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  1. 16 points
    When Minelab started developing our EQUINOX detector, we looked very closely at all of the current market offerings (including our own) to reassess what detectorists were really after in a new coin & treasure detector. A clear short list of desirable features quickly emerged – and no real surprises here – waterproof, lightweight, low-cost, wireless audio, and of course, improved performance from new technology. This came from not only our own observations, but also customers, field testers, dealers and the metal detecting forums that many detectorists contribute to. While we could have taken the approach of putting the X-TERRA (VFLEX technology) in a waterproof housing and adding a selectable frequency range, this would have been following the path of many of our competitors in just rehashing an older single frequency technology that had already reached its performance limits. Another option would have been to create a lower cost waterproof FBS detector, but that also had its challenges with FBS being ‘power hungry’, needing heavier batteries, heavier coils, etc., and relatively high cost compared to the more recent advances that our R&D team have been making with the latest electronics hardware and signal processing techniques. When Minelab develop a new detecting technology we aim to create a paradigm shift from existing products and provide a clear performance advantage for our customers. Our Technology History The multi-frequency broad band spectrum (BBS) technology that first appeared in Sovereign detectors in the early 1990’s provided an advantage over single frequency coin & treasure detectors. This evolved into FBS with Explorer, all the way through to the current CTX 3030 (FBS 2). The multi-period sensing (MPS) PI technology that first appeared in the SD 2000 detector in the mid 1990’s gave a significant advantage over single frequency gold detectors. This key technology exists in the current GPX Series detectors today. Zero Voltage Transmission (ZVT) is our latest gold detection technology implemented in the GPZ 7000 and is a recent example of Minelab’s continued innovation beyond ‘tried and true’ technologies to achieve improved performance. Further to our own consumer products, our R&D team also has significant experience working with the US and Australian military on multi-frequency technologies for metal detection. Introducing Multi-IQ Multi-IQ is Minelab’s next major innovation and can be considered as combining the performance advantages of both FBS and VFLEX in a new fusion of technologies. It isn’t just a rework of single frequency VLF, nor is it merely another name for an iteration of BBS/FBS. By developing a new technology, as well as a new detector ‘from scratch’, we will be providing both multi-frequency and selectable single frequencies in a lightweight platform, at a low cost, with a significantly faster recovery speed that is comparable to or better than competing products. We have come out with a very bold statement that has captured a lot of market attention: “EQUINOX obsoletes all single frequency VLF detectors” Multi-IQ achieves a high level of target ID accuracy at depth much better than any single frequency detector can achieve, including switchable single frequency detectors that claim to be multi-frequency. When Minelab use the term “multi-frequency” we mean “simultaneous” – i.e. more than one frequency is transmitted, received AND processed concurrently. This enables maximum target sensitivity across all target types and sizes, while minimizing ground noise (especially in saltwater). There are presently only a handful of detectors from Minelab and other manufacturers that can be classed as true multi-frequency, all of which have their own advantages and disadvantages. How does Multi-IQ compare to BBS/FBS? Multi-IQ uses a different group of fundamental frequencies than BBS/FBS to generate a wide-band multi-frequency transmission signal that is more sensitive to high frequency targets and slightly less sensitive to low frequency targets. Multi-IQ uses the latest high-speed processors and advanced digital filtering techniques for a much faster recovery speed than BBS/FBS technologies. Multi-IQ copes with saltwater and beach conditions almost as well as BBS/FBS, however BBS/FBS still have an advantage for finding high conductive silver coins in all conditions. “* 20 kHz and 40 kHz are not available as single operating frequencies in EQUINOX 600. The Multi-IQ frequency range shown applies to both EQUINOX 600 and 800. This diagram is representative only. Actual sensitivity levels will depend upon target types and sizes, ground conditions and detector settings.“ Questions & Answers What actually is Multi-IQ technology? What does the name stand for? What frequencies does it use? Is “Multi” the same or different for the various Detecting Modes? Is Multi-IQ the same or different for EQUINOX 600 and EQUINOX 800? Why use a single frequency? How does EQUINOX perform in certain environments? How does EQUINOX perform compared to other Minelab detectors? How does EQUINOX perform against other brand detectors? These are some of the myriad of questions we have seen since we published our EQUINOX Product Notice in mid-September. Some of the answers will have to wait until Minelab publishes reports from our field testers and/or you get your own hands on a detector to try yourself. In the meantime, let’s look further into the aspects of Multi-IQ technology. Multi-IQ is derived from: Simultaneous Multi-Frequency In-phase and Quadrature Synchronous Demodulation. We can go to a statement from Dr Philip Wahrlich, our principal technology physicist, about a key difference of Multi-IQ compared to the demodulation taking place in conventional single frequency VLF detectors: “Within the Multi-IQ engine, the receiver is both phase-locked and amplitude-normalized to the transmitted magnetic field – rather than the electrical voltage driving the transmitted field. This field can be altered by the mineralization in the soil (in both phase and amplitude), so if the receiver was only phased-locked to the driving voltage, this would result in inaccurate target IDs and a higher audible noise level. Locking the receiver to the actual transmitted field, across all frequencies simultaneously (by measuring the current through the coil) solves these issues, creating a very sensitive AND stable detector” Precisely measuring these extremely small current variations is quite remarkable if you consider the levels involved. It’s actually parts per billion, or nanoamp signals, we are talking about here! With Multi-IQ, we can derive much greater target ID accuracy and increased detecting performance, especially in ‘difficult’ ground. In ‘mild’ ground, single frequency may perform adequately, BUT depth and stable ID’s will be limited by ground noise; whereas the Multi-IQ simultaneous multi-frequency will achieve maximum depth with a very stable target signal. In ‘strong’ ground, single frequency will not be able to effectively separate the target signal, giving decreased results; whereas Multi-IQ will still detect at depth, losing a minimal amount of target accuracy. This is how we would generally represent the multi-frequency advantage, based on our engineering test data. Let’s hear more from Philip Wahrlich about the technical details: “For each frequency the detector transmits and receives there are two signals which can be extracted which we refer to as I and Q. The Q signal is most sensitive to targets, while the I signal is most sensitive to iron content. Traditional single-frequency metal detectors use the Q signal to detect targets, and then use the ratio of the I and Q signals to assess the characteristics of the target and assign a target ID. The problem with this approach is that the I signal is sensitive to the iron content of the soil. The target ID is always perturbed by the response from the soil, and as the signal from the target gets weaker, this perturbation becomes substantial. With some simplification here for brevity, if a detector transmits and receives on more than one frequency, it can ignore the soil sensitive I signals, and instead look at the multiple Q signals it receives in order to determine a target ID. That way, even for weak targets or highly mineralized soils, the target ID is far less perturbed by the response from the soil. This leads to very precise target IDs, both in mineralized soils and for targets at depth.” “How many simultaneous frequencies?” you may ask, wondering if this is a critical parameter. Minelab has been carrying out detailed investigations into this in recent years. Just as you can color in a map with many colors, the minimum number to differentiate between adjacent countries is only 4 – a tough problem for mathematicians to prove, over many years. Similar to the map problem, it’s perhaps not the maximum number of frequencies needed to achieve an optimum result, but the minimum number that is more interesting. When it comes to frequencies in a detector, to cover all target types, how the frequencies are combined AND processed is now more important, with the latest detectors, than how many frequencies, for achieving even better results. Efficient new technology = lower power = lighter weight = higher performance. The above diagram is intended to be a simplified representation of how different frequencies of operation are better suited to different target types; i.e. low frequencies (e.g. 5kHz) are more responsive to high conductors (e.g. large silver targets) and high frequencies (e.g. 40kHz) are more responsive to low conductors (e.g. small gold nuggets). The EQUINOX 600 offers a choice of 3 single frequencies and the EQUINOX 800 offers the choice of 5 single frequencies. Both models also have simultaneous multi-frequency options that cover a much broader range of targets than any one single frequency can – and they’re different across the Detecting Modes! Our goal was to develop a true multi-purpose detector that could not only physically be used in all-terrain conditions, but also be suitable for all types of detecting for all detectorists, and particularly those not requiring a specialist premium flagship detector optimised for only one aspect of detecting – e.g. coins, beach, gold, jewelry, water, discrimination, artefacts, etc. This multi-purpose requirement is something that could only be achieved by going beyond single frequency and creating the next generation of multi-frequency technology. Equally adaptable to all target types and ground conditions – just select your detecting location and go! An important update on the Detect Modes… Previously we have stated that Park, Field and Beach would run in multi-frequency and that Gold would only use the single frequencies of 20kHz and 40kHz, giving better results for gold nugget hunting. Our ongoing collaborative field testing feedback from around the world has resulted in further improvements to Multi-IQ to the point where multi-frequency is now the best option for Gold Mode as well, and will be the default setting. Please refer to the revised Getting Started Guide for updated product functions. Now, back to the technology: looking into our Multi-IQ diagram further… a single frequency is most sensitive to a narrow range of targets and multiple frequency is equally sensitive to a wider range of targets (e.g. the orange curve versus the white curve below). According to Philip Wahrlich, “From our testing, the Multi-IQ deployed in EQUINOX detectors has shown no significant trade-offs relative to the best single-frequency detectors and exceeded performance benchmarks in many important attributes, especially discrimination. And, for good measure, EQUINOX can also be operated as a single-frequency detector” While we could delve into this aspect further, many of our readers are likely more interested in what happens within the white Multi-IQ band itself, rather than single versus multi. What has Minelab developed new, and uniquely, with frequencies to give better performance across the whole range of targets for different conditions? The Multi-IQ transmit signal used in EQUINOX is a complex waveform where multiple frequencies are combined in a very dissimilar way than our proven BBS/FBS technology in Excalibur II / Safari / E-TRAC / CTX 3030 detectors. If you view the BBS signal amplitude on an oscilloscope, it looks something like this: In comparison, Multi-IQ looks something like this: Hence – Multi-IQ is not a derivative or evolution of BBS/FBS. Multi-IQ is a DIFFERENT method of simultaneous multi-frequency metal detection. We could also debate “simultaneous” versus “sequential” semantics; however the real detection ‘magic’ doesn’t happen with what is transmitted to and received from the coil alone. Remember, in Part 2, we discussed how frequencies are “combined AND processed” as being important for achieving better results? Let’s assess Multi-IQ for the different Detect Mode search profiles: Park 1 and Field 1 process a lower weighted frequency combination, as well as using algorithms that maximise ground balancing for soil, to achieve the best signal to noise ratio. Hence being most suited for general detecting, coin hunting, etc. Park 2 and Field 2 process a higher weighted combination of the Multi-IQ band while still ground balancing for soil. Therefore they will be more sensitive to higher frequency (low conductive) targets, but potentially more susceptible to ground noise. Beach 1 also processes a lower weighted combination, BUT uses different algorithms to maximise ground balancing for salt. Hence being most suited for both dry and wet sand conditions. Beach 2 processes a very low weighted frequency combination, using the same algorithms as Beach 1 to maximise ground balancing for salt. This search profile is designed for use in the surf and underwater. Gold 1 and Gold 2 process the higher weighted combination of the Multi-IQ band while still ground balancing for soil. However, they use different setting parameters better suited for gold nugget hunting. Earlier we discussed the different Multi-IQ “frequency weightings” for the different search profiles. Now let's explain further why it is not a simple matter of just referring to specific individual frequencies for learning more about Multi-IQ technology. Let’s now consider one of the key practical detecting outcomes and then discuss how this was achieved… “A lot of people are going to be surprised at how well the machine works in saltwater. At the outset we weren’t sure whether reliably detecting micro-jewelry in a conductive medium was even possible, but – with the help of our field testers and the subsequent fine-tuning of the Multi-IQ algorithms – we’ve found the EQUINOX to be more than capable.” Dr Philip Wahrlich Background and considerations While Multi-IQ may appear as ‘magic’ to some, to our team of signal processing experts, it’s the result of a significant number of man-years of development. So where did they start? By assessing the metal detectors and technologies available in the market at that time, along with typical customer perceptions about their practical applications; and actual detecting results achieved: So, an important goal with developing Multi-IQ technology was to retain the above simultaneous multi-frequency advantages AND greatly improve performance in the two key areas where many single-frequency detectors typically excel – fast recovery in iron trash and finding low conductors in all conditions. Speeding up the process Most comparable low-power Continuous Wave transmit-receive detectors (for the same coil size) will have a similar raw detection depth at which the transmit signal penetrates the ground and has the potential to energize a target. To increase detection depth significantly typically requires higher power and Pulse Induction technology. This has advantages for gold prospecting, but discrimination is poor for identifying non-ferrous targets. While we continue to push for depth improvements, Multi-IQ also aims to provide substantial speed improvements, resulting in being able to better find ALL non-ferrous targets among trash in ALL locations. You could therefore say “fast is the new deep, when it comes to EQUINOX!” Let’s start with considering signal processing not as a ‘black box’ where ‘magic’ happens, but more as a complex chain of applied algorithms, where the goal is to more accurately distinguish very small good target signals from ground noise, EMI and iron trash. Now, ‘fast’ by itself is not enough – you can have fast with poor noise rejection and poor target identification, giving no great advantage. Fast is also not just a result of microprocessor speed. Processors operate at much higher speed than is needed to ‘do the signal processing math’. You can think of the signal processing chain broadly as a set of filters and other processes which are applied to the metal detector signals to convert these signals into useable, informative indicators, such as an audio alert or a target ID. For Multi-IQ, keeping the ‘good’ properties of these filters, while keeping them lean and removing unnecessary processing, was an important step towards achieving ‘fast’ for EQUINOX. It’s also important to recognize that these filters are not the coarse filters of the analogue electronics hardware of last century – it all happens in software these days. Perhaps think of the older analogue TV standards versus current digital TV. (Standard digital HDTV has approx.10 times the resolution of analogue NTSC.) With metal detectors, a fast higher resolution filter set will result in improved target recognition. Factoring in the ground conditions However, speed without accuracy is not enough to produce a “game changer” detector – and improved accuracy cannot be achieved with a single frequency alone. Why? – “multi-frequency has more data-points” Philip Beck, Engineering Manager. This is worth explaining in more detail… All transmit-receive detectors produce in-phase (I) and quadrature (Q) signals that can be processed in various ways depending upon the response received from targets, ground and salt. This processing happens through ‘channels’ that have different sensitivities to the different signals received. It is important to recognize that channels are not exactly frequencies. This is why it is more complex to explain than just correlating optimum frequencies to specific target types. With a single frequency detector there are two basic channels for information (i.e. I and Q) that respond differently to good and bad signals, depending upon the frequency of operation and whether you are looking the the I or Q signal. It is also possible to scale and subtract these signals, while taking ground balance into account, to best maximize good signals and minimize bad signals. You could thus think of single-frequency being Single-IQ, with a limited set of data (e.g. I, Q, I-Q, Q-I) that works well for a particular set of conditions. To further enhance performance for a different set of conditions, you need to change frequency and detect over the same ground again. Therefore a selectable single frequency detector has an advantage with more data available, but not all at once (e.g. I1, Q1, I1-Q1, Q1-I1 OR I2, Q2, I2-Q2, Q2-I2 for as many frequencies that you can select from). Now, getting back to Philip Beck’s “more data-points”, and just looking at two frequencies, a simultaneous multi-frequency detector would be able to process (for example) I1, Q1, I1-Q1, Q1-I1 AND I2, Q2, I2-Q2, Q2-I2 AND I1-Q2, Q2-I1, I2-Q1, Q1-I2 to give better detection results. Increase the number of frequencies further and the number of extra data-points also increases accordingly. What Multi-IQ does is process different optimized channels of information (not just individual frequencies) for the different modes. We have previously explained this as “frequency weighting” (in Part 3), where the various EQUINOX Search Profiles are matched to the respective ground conditions and target types. Here is a very simplified example where you can see the result of processing more than a single channel of information (remember, a channel is not a frequency): Channel 1 has a strong target signal, but the salt signal is stronger still. Channel 2 has weaker signals for soil, salt and the target. If the detector just responded to either Channel 1 or Channel 2, the target would not be heard through the ground noise. If the detector processes a subtraction of the channels (e.g. ch.1-ch.2), then it is possible to ignore the ground noise and extract a strong target signal. Now, think back to the high number of possible combinations of I and Q for simultaneous multi-frequency compared to single-frequency and the frequency weightings for the modes. All of the EQUINOX Park, Field, Beach and Gold Search Profiles have dedicated signal processing to best suit the conditions and types of targets being searched for. Conclusion Multi-IQ = more data-points = sophisticated processing = better ground noise rejection = more finds Just as targets are more sensitive to certain frequencies, so is the ground – an important reason why air testing has inherent limitations when comparing detector performance. As soon as you have ground to consider in the signal processing equation, it can greatly impact on the ability of a single-frequency detector to accurately identify a target. Also, the deeper a target is buried, the weaker the target signal is, relative to the ground signal. The most difficult ground response to eliminate is the salt response, which varies greatly between soil, dry sand, wet sand and seawater. It is not possible to eliminate the salt response and the soil mineralization response (e.g. black sand) with just one frequency. However, within the carefully calibrated Multi-IQ channels, EQUINOX is able to identify both signals and therefore mostly ‘reject’ them (just as you would notch discriminate an unwanted target) BUT still detect gold micro-jewelry. The above article is a compilation of a series of blog entries taken from Minelab's Treasure Talk. More will be added here as available.
  2. 11 points
    The White's Goldmaster 24K has been announced and has just started shipping to customers. The Goldmaster 24K is an alternative to the White's GMT updated for the 21st century, with advanced ground tracking technology and increased power. XGB technology is a patent-pending automatic ground balance system. It is purpose-built for operating a high-frequency VLF gold nugget detector in the worst ground conditions. Traditional VLF detectors struggle to balance rapidly changing ground mineralization. Historically this has been where Pulse Induction machines fared much better. With XGB technology, the Goldmaster 24k is able to track small changes in soil composition as well as longer-term shifts in both ground phase and strength. This allows it to operate in ground that traditional VLFs struggle in. Users have extended control over the range of XGB in the Goldmaster’s All-Metal mode. Simply enable Iron Cancel to expand the ground filter in moderate soils. In very challenging soil conditions, hold the Iron Cancel button and select the 2-bar setting for maximum performance in variable ground. New 9/12/18 - Detailed Review Of White's New Goldmaster 24K White's Goldmaster 24K metal detector - new for 2018 The new White's Goldmaster 24K also features a full backlit LCD target id screen and control suite. The potential target id is displayed on the screen whenever possible - the higher the number, the better the chance of a non-ferrous target. There is dual tone capability that reports a low tone for ferrous objects, and a high tone for all non-ferrous targets. White's Goldmaster 24K Features SENSITIVITY - Set the sensitivity at a level that does not result in false signals from the ground. Very strong ground may result in the symbol on screen and a loud sound - this means the sensitivity is too high. GROUND BALANCE - With the default setting, the detector will use XGB to automatically ground balance. Tap to lock the ground balance to the current setting. Tapping when the ground balance is locked will update the current ground setting to what is under the coil. GROUND SCAN - Hold to put the detector into Ground Scan mode. The top bar displays the ground strength and the two digit numbers display the ground type (phase). Useful for tracing paystreaks. IRON CANCEL - Tap to silence hot rocks, trash and mineral changes in both audio modes. Hold to select the Iron Cancel setting (1 bar is default). Note that this setting may decrease the detector’s sensitivity to very small gold, but is necessary in difficult ground conditions. VOLUME and THRESHOLD - Tap to adjust the volume with the up and down buttons. Hold to adjust the threshold with the up and down buttons (“th” displays on screen). Set these to a comfortable level for your hearing and preference. AUDIO MODE - With the displayed on screen, the detector is in “BEEP” audio mode (high tone = good target, low tone = bad target). The default setting (without on screen) is a traditional All-Metal audio mode with greater sensitivity to small targets. SAT - SAT can smooth out ground inconsistencies. Hold to adjust it (“Sa” displays on screen, 2 is the default setting). PINPOINT - Hold for non-motion pinpoint mode. In difficult ground this mode may be affected by mineralization. BACKLIGHT - Tap to enable the backlight (this reduces battery life). FREQUENCY SHIFT - Hold when turning the detector on to shift frequency (useful when there is EMI). Power off to save the selection. FACTORY RESET - Hold when turning the detector on to perform a factory reset. Not only does the new White's Goldmaster 24K features a new ground tracking system, but the gain has been boosted with an increase of voltage to the coil. From the Advanced Guide (link below): "When our engineers set out to build the GM24k, the goal was simple: improve the user’s chance to find gold without hurting their wallets. The obvious way to achieve this goal is increased sensitivity. The GM24k features a 54% increase in coil voltage over the GMT. You will see this in increased sensitivity to small nuggets. While testing this machine in Brazil, this was shown in a tiny, 0.4 grain crystalline nugget we found encased in quartz. In some cases this much power can be counter-productive if the ground is very challenging, so use it with caution! Even at lower gain settings the GM24k is an extremely “hot” machine on small gold and specimen nuggets." The new White's Goldmaster 24K comes with both rechargeable batteries and a holder for AA batteries. The GMK comes standard with the 6" x 10" DD search coil. Currently the is one accessory coil available, a 6" round concentric coil. Both a 14" x 8" DD and 6" x 4" DD coil are possible in the future but have yet to be offered for sale as of March 2019. White's Goldmaster 24K display and controls Here is a video released August 8, 2018 that goes over the basic features and operation of the Goldmaster 24K... Official White’s Goldmaster 24K Page White's Goldmaster 24K Quick Start Guide White's Goldmaster 24K Owner's Manual White's Goldmaster 24K Color Flyer Detailed Review Of White's New Goldmaster 24K White's Goldmaster 24K & GMT Compared Forum Threads Tagged "whites goldmaster 24k" White’s Metal Detector Forum White's Goldmaster 24K Technical Specifications* Internet Price $729 Technology Induction Balance (IB) Frequency 48 kHz Autotune Mode(s) Variable Self Adjusting Threshold (V/SAT) Ground Rejection Tracking & Fixed w/Grab function, Ground Balance Offset Soil Adjust No Discrimination Visual & Audio Ferrous ID Volume Control Yes Threshold Control Yes Tone Adjust No Audio Boost Yes Frequency Offset Yes Pinpoint Mode Yes Audio Output 1/4" headphone socket & speaker (Headphones Included) Hip Mount Shaft Mount Only Standard Coil(s) 6" x 10" DD Coil standard Optional Search Coils 6" round concentric coil Battery Rechargeable NiMH plus Eight AA Pack Included Operating Time 20 - 40 hours Weight 3.5 pounds Additional Technology XGB Ground Tracking Technology, Ground Scan mode for tracing black sand deposits, Meter backlight Notes IP54 Rain & Dust Resistant *Notes on Technical Specifications - Detailed notes about the specifications listed in this chart. From this thread: GOLDMASTER 24K WHITE'S PAPER XGB - A New Way To Ground Balance The biggest challenge we face as electronic prospectors is highly mineralized ground. Simply increasing the gain on the current VLF platforms might help prospectors in very mild ground conditions, but what about more difficult areas with concentrations of black sand, maghemite, serpentine, or alkali salts? On a trip to Brazil we witnessed a combination of these conditions, with soil that ranged from red to black to purple, and exhibited a combination of ferrous and alkali properties within a 4 ft square section. We saw first-hand VLFs from each manufacturer fail to balance out the combination of minerals. Even the top-of-the-line pulse induction machines struggled in this area - machines which cost the garimpeiros (the local term for gold miners) several years’ wages. Our goal was simple: a nice even threshold in challenging ground conditions without giving up sensitivity. The theory is that the main battle most electronic prospectors fight is being able to discern a potential gold signal from ground noise. A smooth threshold would allow users to use more gain and increase their odds of finding small gold where it likes to hide - in mineralized ground. The issue with other VLF detectors on the market is that they were tracking a single ground balance point. When the ground type changes quickly, the machine gives off a false signal. For a user the result is ear fatigue, frustration, and less positive signals dug. One easy way to mask variable ground is implementing an auto-gain feature that automatically numbs the detector. This does not solve the issue, only hides it. The Goldmaster 24k’s XGB is a new automatic ground tracking system that works by tracking multiple ground points simultaneously and quickly. Where other VLF’s track one ground balance point, the Goldmaster 24k tracks several, and can determine an optimal “ground window” based on ground history and strength. This is very useful in rapidly changing ground conditions, where other VLF machines may struggle to track the mineralization changes. Combine this with the speed at which the Goldmaster 24k is able to grab ground samples, and you have a superior ground balance system for a prospector’s VLF. XGB Ground Balance versus legacy methods With any automatic process, there are some concessions. Take vehicles for example - manual gearboxes are still preferred by car enthusiasts. That’s why we felt strongly about including a TracLock® ground option. When used with the Ground Grab, a locked ground balance setting allows users to set the ground balance in an area and lock it until they need to re-ground balance. For users after the tiniest bits of gold, this option allows for the maximum sensitivity to small signals. One technique we observed from field testers was allowing the XGB to automatically track, and then after getting a solid hit or finding a patch, locking the ground balance for target location and retrieval. For many users this combination will be the best of both worlds - the strength of XGB, but only when you need or want it. The net result of an overhauled automatic ground balance system is a VLF gold nugget detector that can be used in wider variety of ground conditions with a nice stable threshold. Operating a machine with a smooth threshold allows for a user’s ears to tune into those slight variations that just might be the next nugget. Our goal is that our customers are able to have success with the Goldmaster 24k in areas that other VLF’s struggle, and at a price that allows more people to get a taste of electronic prospecting. Tom Boykin White's Project Manager Gold nuggets found with new White's Goldmaster 24K - smallest under 1/10th grain
  3. 10 points
    White's MXT Engineering Guide David E. Johnson, engineering consultant This Engineering Guide is written to provide dealers and customers greater insight into what kind of product the MXT is, from an engineering perspective. It does not attempt to provide complete information on the features and use of the MXT: for that, please consult the MXT user's manual. A BIT OF HISTORY In January 1998, White's decided to develop a true multipurpose metal detector, with the kind of sensitivity it takes to be a real gold prospecting machine, and with computerized ground tracking for ease of use. White's in-house engineering staff was tied up on the project which eventually became the DFX. Therefore, in February White's asked me if I might be interested in taking on a new protect. I had a good track record on gold machines so it seemed like a good fit. I agreed. A month later at a dealer seminar in Sacramento, California, Jimmy Sierra announced the project, and said if the engineer didn't deliver, the engineer would have to go into hiding in Mexico. I was sitting in the back. We ran into one problem after another along the way. Jimmy, good chap that he is, didn't sic the thugs on me, though there were periods he was frustrated enough that the thought must have run through his mind. Although the project took longer than we expected we got two products out of it - the GMT and the MXT. The first major hurdle was to get the basic circuit and software system running, with a first class ground tracking system. The system architecture was totally new, not a revision of the existing Goldmasters. In early spring of 1999 an ugly prototype was up and swinging, and Larry Sallee became involved in field-testing. By April the ground tracking system was working so well that since that time very few changes have been needed. At that point we knew we had a solid foundation, so work began on the display, discrimination and target ID features. During the fall of 1999, we decided to tackle the problem of desert heat head-on. A lot of gold prospecting is done in desert heat in full sun. I set up a crude but effective, thermal engineering laboratory, measuring the temperatures reached inside housings of various configurations and colors in full sun. Then began the task of finding an LCD, which would handle the heat. Because the LCD display is an important feature of the MXT, we revisited the whole issue of display. The manufacturers of LCD display had expanded their product offerings. We found a larger one, and changed the mechanical design of the MXT to accommodate it. A FSTN 0160 F was selected, (there are more to choose from nowadays, so we used a bigger one than the GMT in the MXT.) In early 2000, White's decided to bring out a new Goldmaster based on the work that had already been done, while development of the multipurpose unit continued. So we modified a prototype to work with the Goldmaster search coil at about 50 kHz, and you know the rest of that story - the GMT "tracking Goldmaster" was introduced in early spring of 2001. As work continued on what eventually came to be called the "MXT", we spent a lot of time on the discrimination and target ID system. There are many different ways to do discrimination and ID, each with its own advantages and disadvantages, which aren't always known until you've had the thing in the field being tested for a while. A lot of work got thrown out as we found deficiencies in what had already been done, and discovered ways to improve things. As the project got closer to production, more people became involved with it, and offered their own ideas to improve it. The reason the MXT is as good as it is, is because of that long process of field-testing and revisions. While the MXT was still under development, the DFX was introduced. The MXT design was then revised to run at about 14 kHz in order to take advantage of the DFX loops. When it was finally time to call it "good" in June 2002, the MXT went into production quickly and smoothly. CIRCUIT DESIGN The circuitry of the MXT is almost identical to the GMT, which has already been on the market for a year and a half and has proven to be rock-solid. The GMT's circuitry broke a lot of new ground. It uses a reactive impedance transformation network to boost transmitter voltage for higher sensitivity. It uses an active transmitter regulator to keep transmitter voltage constant even when the search coil is moved over black sand that would blow an unregulated machine off the air. The differentiator-filter circuits usually found in metal detectors are eliminated. Those functions are now done in software, which is made possible by the use of a high-precision 16-bit A/D converter used in a way that makes it equivalent to 17 1/2 bits. All the controls are digitized, their function actually performed via software rather than in circuitry. The audio system is temperature compensated in software to eliminate threshold drift. For the MXT, we chose an operating frequency of 13.889 kHz. This is high enough to give good sensitivity to gold, low enough to give good target ID on typical coin, trash, and relic targets, electrically compatible with search coils derived from the DFX and halfway in between power line harmonics to minimize electrical interference. SOFTWARE The MXT uses a Microchip PIC 16C76 micro controller, chosen for its low power consumption and its set of features, which was a good match for this application. The software that runs in this chip is based on that in the GMT, but almost all of it is new or has major revisions, except the device drivers and the ground tracking system. Much of the new software is for target ID and discrimination, features that were not present in the GMT. Even the iron probability and VSAT systems in the MXT are new, despite their apparent similarity to the GMT. The MXT/GMT does as much of the signal processing as possible in software rather than in circuitry, using what we call "low-speed DSP architecture". The demodulated signals are digitized, and processed and analyzed in software. Control positions are also digitized and made part of the data in software. The desired audio signal is computed, and then converted back to voltage using a 12-bit D/A converter. The circuit board communicates with the LCD and trigger switch in the "pod" via a custom-designed serial link. In the MXT the filters, differentiators, and sample-and-hold functions are performed in software, not in circuitry. This eliminates the problems of channel mismatch and drift, which are often encountered in such circuits. The discrimination system is a second derivative ("two-filter'') design for quick response over a broad range of sweep speeds. The analysis system for determining what kind of target is present has special features which reduce interference from ground minerals, and which automatically scale target ID confidence according to the mineralization level. GROUND TRACKING SYSTEM The ground tracking system comprises two subsystems: a ground analysis engine, and a ground balancing system. The ground analysis engine continuously monitors incoming signals to determine whether the signals probably represent ground, or may be something else such as metal targets or electrical interference. Signals, which seem to be ground only, are put into a data analysis subsystem, which analyzes the data for a number of variables. Then it can be determined what the balance point of the ground matrix is and how fast that balance point is changing. It'd be nice to describe all this in detail but we'd rather not teach our competitors how to do it. The ground balance system does the actual balancing of the signals, doing in software somewhat the same job as a ground balance knob does on a manually balanced machine. When the TRAC toggle is in the "ground" or "salt" positions, the ground balancing system follows the output of the ground analysis engine. When the toggle is in the center "lock" position, the ground balance subsystem stops following the output of the ground analysis engine, which is still chugging away in the background continuing to gather ground data. The ground analysis engine can do a good job of telling the difference between ground matrix and anomalies such as hot rocks and metal targets. In order to tell the difference, it has to see matrix by itself during at least part of the sweep. When you're not in "lock", keep your sweeps broad, and don't loiter over the top of a target when checking it out. Otherwise the analysis engine may lose the ground matrix and start tracking into the target. However, if the target is strong enough to register on the VDI readout, the target ID system will tell the analysis engine to halt, allowing you to check the target without tracking into it. In all three programs, pulling the trigger to pinpoint a target also tells the ground analysis engine to halt. Some users will hunt with the tracking toggle in "lock", occasionally updating the ground balance by flipping into "ground" or "salt" momentarily when they start hearing too much ground noise. The resolution of the ground balancing system is 1 part in 4,000, and most of that resolution is concentrated in the range where high mineralization occurs. Therefore, the individual resolution steps are below audibility under all conditions. THE VSAT SYSTEM The VSAT system on the MXT is similar in a general way to the one on the GMT. The VSAT function is done entirely in software. Up to about 2/3 rotation, the SAT is of the conventional (first derivative or auto tune) kind, giving a "zip" sound on a nugget and a "boing" sound on a negative hot rock (cold rock). As you approach maximum rotation, the MXT goes into "HyperSAT". HyperSAT is a completely different type of SAT system with different sounds and target responses. The background threshold sound is a little rattier, but nuggets are crisper, the ground is quieter, and negative hot rocks vanish when you slow down your sweep. For all but the most experienced users whose ears are calibrated to hear every little nuance of a regular SAT signal, HyperSAT gives more effective depth in bad ground than normal SAT. THE DISCRIMINATION CONTROL The discrimination control does pretty much what you'd expect. Unlike some discriminators, when the control is at zero, there is no discrimination at all - i.e., "true zero discrimination" - and all targets will be detected. Below about 2, the discrimination is based on a combination of both signal phase, and signal strength relative to the strength of ground mineralization. This feature allows the user to get good rejection of shallow iron with minimal loss of deeper targets. THE GAIN CONTROL The gain control knob controls two things at once: the preamp circuit gain, and the software gain. The following is a simplified explanation which is not technically correct in all its details, but will serve to give a general picture how the gain control works. As you advance the gain control from 1 to 10, the preamp circuit gain steps through five levels of gain: xl, x2, x4, x8, and x16. On most machines (depending on minor variations in search coil alignment) you can hear a momentary blip as the machine switches from one gain level to the next. The recommended preset (marked by the triangle) corresponds to a preamp gain of x8. In mild ground conditions where there is no electrical interference, you may want to advance the gain control into the crosshatched region. In this region, the signal data in software is multiplied by successively larger numbers, increasing the loudness of the signals. It is somewhat similar to the "audio boost" function found on some other models of metal detectors. It's particularly useful if you're using the speaker rather than headphones and there's a lot of noise from traffic or wind, or if you're demoing the machine to someone else. BASIC SENSITIVITY PERFORMANCE Since this is a multiple-purpose machine, a U.S. Nickel coin is the most appropriate standard test target. With the gain cranked up, and in the absence of electrical interference, a nickel will typically "air test" beyond a foot using the standard 95O search coil. Your actual "air test" distance will depend on your hearing, the sweep speed, what search coil is used, how much electrical interference is present, and how you have the controls set. In comparison to other machines in this price range, the MXT is extremely hot on low-conductivity items. On gold, it's right in there with the more popular gold machines, being especially hot on the larger, deeper nuggets. It will compete with all comers on low-conductivity , relics and on nickels. On high conductivity coins such as quarters and silver dollars, it is still an excellent performing machine, but there are several other products in the same league for sensitivity. GROUND TRACKING PERFORMANCE The ground tracking system is nearly identical to that in the GMT, which is widely regarded as one of the best tracking systems on the market. Compared to most other trackers, the MXT has superior resolution, tracks faster, "jumps" into new ground more quickly, has greater resistance to tracking into targets, and tracks over a wider range of soil conditions. The MXT allows tracking to be inhibited if desired. DISCRIMINATION PERFORMANCE All discriminator designs are compromises. Here's how the discriminator in the MXT stacks up against other machines. AIR TEST "DEPTH": generally well beyond 10 inches, because of high sensitivity, with effective discrimination to within 0-3 inches of the basic air sensitivity of the target. Most discriminators will discriminate in air to within 0-3 inches of the target air depth on most targets, but most don't have the sensitivity of the MXT. QUICKNESS & TARGET SEPARATION: among the best, because of medium-speed second derivative ("two-filters") design. Initial field reports indicate that the MXT's mixed-mode tone system gives indication of adjacent ferrous/nonferrous targets, superior to that obtainable through discrimination. IRON REJECTION: Because of its high sensitivity and a slight preference in the software for not losing questionable targets, it'll be a little chattier than some less sensitive machines. Reducing sensitivity by cutting back on gain, or by reducing the threshold control setting to minimum, will help quiet it down when necessary. DEPTH IN MINERALIZED GROUND: Although the MXT is a two-filter system, it incorporates special techniques which reduce ground interference and which reduce the "chopping & popping" which plague most other two-filter machines. This, together with its high basic sensitivity, makes it an excellent machine from the standpoint of discrimination depth. FAST SWEEPING: Many discriminators tend to lose good target signals, even shallow ones, when quickly sweeping the search coil. The MXT is tolerant of moderate search coil sweeps, that is to say good at both faster and slower search coil paces. SUMMARIZING: The MXT has the responsiveness and sensitivity of a first-rate 2 filter machine, combined with the discrimination accuracy of a first-rate 4-filter machine. TARGET I.D., ETC. With its small medium and large blocks on the target ID screen, the ID system in the MXT bears a superficial resemblance to the "Signagraph" of the Spectrum XLT. It should be realized that the traditional White's Signagraph system is typically (optionally) set to accumulate data over multiple passes over a target, and displays the accumulated average. The MXT displays fresh data on each pass and scales the size of the block according to how strong the signal was relative to the ground conditions on that specific pass over the target. The visual ID system on the MXT is fast, easy to read, generally more accurate than the discriminator, and gives a visual indication (via block size) of how reliable the identification is. It is going to change the minds of many beeper enthusiasts who previously thought visual ID to be of little practical use outside typical coin shooting. CASCADE THE CASCADE OF EFFECTS OF GROUND BALANCE SETTING: In order to know what the ground balance setting is; flip momentarily to the gold program if you were in another mode. Electronic ferrite material and most "negative hot rocks" (cold rocks) will usually read in the 75-88 range. Most soils will read somewhat lower. Readings will almost never go below 25 except in salt or moist alkali soils. When readings indicate smaller numbers than 50 you may notice some reduction in sensitivity. Below 35, some rusty iron may give unpredictable responses. Below 25, iron objects may give unpredictable responses and/or may disappear entirely and the sound on nonferrous objects may become slightly more abrupt. MANY THANKS To Kenneth White and Alan Holcombe for having sufficient confidence in me to put food on my table through the good times and the rough times on this project. To Jimmy Sierra for having the patience to argue with me about all the stuff that needed arguing about, for being so passionate about the need for this product, and for being willing to compromise when that's what it took to keep the project moving. To Larry and Sue Sallee, for their personal hospitality and for field testing prototypes. To Keith Zorger, Randy Smith, Mike Brighty who field-tested and helped develop the MXT. To Bob Canaday, for being such a competent technical/engineering liaison, doing a lot of not glorious but necessary work well and managing the project during its sometimes difficult phases. To Rick Maulding, for overseeing the project, for technical contributions to the discriminator and to the salt system, and for committing White's engineering department's finest minds to engineering review during the "slow SAT isn't hot enough" crisis, which led to a major system revision that made the whole machine better. To John Earle and Dan Geyer, for diligently hacking away at problems until they became non-problems. To Steve Howard and Pam Godell of White's. There were other people involved in this project whose contact was primarily or exclusively with White's and not with me. The risk of printing credits is that one may inadvertently omit a name that belongs there; so, if I missed someone whose name belongs on this list, I'm sorry, it was an unintentional oversight. - D.E.J. P/N 621-0468 published 8/2002 by White's Electronics
  4. 9 points
    Where Do I Begin? by Ron Wendt You’ve developed an interest in prospecting for gold. A couple friends have told you how much fun they’ve had looking for gold. In this article I’ll point out the pros and cons about this activity and in the end you’ll probably have decided to what degree you want to pursue your search for gold. To begin with, it must be pointed out, there are several types of prospectors: 1 - Those who wish to dig right in as a recreational prospector. 2 - One who is serious about learning about the finer aspects of geology related to precious metals and would pursue possibly developing potential income from this endeavor. 3 - A hardcore, hand miner “give me a bulldozer, I wanna gamble.” Of course mining can be a gamble and the biggest mistake some folks make is getting too serious about it. Many times most of the fun goes right out the window when it becomes serious. What happens is the deep desire for gold becomes elusive and discouragement sets in when there are no results. Looking for gold can be hard work with few rewards. Years ago an old timer once told me; “the fellows that got rich during the gold rush were just plain lucky!” Napoleon once said that too: “I want good generals, but I also want lucky ones!” Yes, there is a lot of luck in this business. The old timer and Napoleon were right. A lot of it is luck, but a lot of it is hard work to. You can choose to enjoy it with a little reward or to not enjoy it with little reward. The truth is the odds are you won’t get rich, but you might get lucky! We all know about luck. You can go to the gambling hall and pull on the “one armed bandit,” all day and not make a dime. Such is mining and prospecting. I’ve been lucky and I’ve been unlucky. I’ve been rich and I’ve been poor. I like rich better, and I like getting lucky. Shoveling gold bearing dirt into power sluices To be a prospector you must be willing to take a risk to a certain degree. There are those who think they can go out and simply put their shovel into the ground and there it is! They believe they’ll strike it rich. I have known some who have struck it big their first few times out. They didn’t have a clue, but were in the right place at the right time. There are several things in your character you should be aware of. 1 - You should be the type of person not easily discouraged. 2 - You should not be afraid of getting dirty and not afraid of hard work. 3 - You should have a keen interest in exploring, prospecting things that are related in this field because it is all connected. 4 - Be frugal. Don’t mortgage the farm. It doesn’t take much in the way of investment to get into this “field of study,” as I call it. 5 - You should not be afraid to get wet, camp out, or endure the elements. 6 - Attitude is a major in this business of mining/prospecting. This probably goes along with “don’t be easily discouraged.” 7 - Don’t be afraid to fail. Failure is a great learning experience. 8 - Have some curiosity about what could be over the next hill or under the next rock. 9 - Be optimistic. If you’re not, you probably shouldn’t be in this business. 10 - Most of all enjoy it. Enjoy it even though you don’t get rich from it. Your reward is experience and experiences many will never have the opportunity to do. Where do I begin? First off don’t go out and buy a bulldozer, when a gold pan can simply do the trick. In other words, start out learning the basics. Those basics are the gold pan, pick, shovel, sluice box, and perhaps a sniffer bottle to suck up gold from cracks. It would be good to go along with a veteran, not only to see how it’s done but to see if you like it. I have seen many times where folks will go out and buy a $1,500 suction dredge only to sell it the next year because they probably got discouraged, when a gold pan and hand tools would have sufficed. A big majority of prospectors I know will tell you they started out small, by that I mean, small mining tools which would include sluices, gold pans, picks and shovels. Once you decide you will make prospecting your side line, one can eventually branch out into other methods. Dredging for gold There are some who will head out into the world of nugget detecting. Here’s something to think about. When you spend $600 to $1,000 on a brand name detector, before you even make a decision to buy it, ask yourself this; “Where will I use it?” This may seem like a funny question, but in Alaska and the Yukon Territory, we may have a lot of gold scattered around up here, but is it detectable and accessible? Will I be able to drive somewhere during my time off from my regular job and spend enough time detecting nuggets? Is there a location close by where gold is detectable? Am I willing to invest this kind of money to use this machine in a proven area? There’s nothing worse than buying a piece of mining equipment and not be able to get into areas that are productive. For instance, the mountains behind my house generally yields mostly fine gold and some hardrock gold. For me to get any bigger gold I must travel south of my house about two hours down the highway or 5 to 10 hours to the north to get into productive ground. I am willing to spend times going to my favorite remote spots in search of gold. So you must determine how much am I willing to put into this to get results? It’s the same with going from your gold pan/sluice operation to a high banker or a suction dredge. Are you planning on a few choice trips to areas to get results, which by the way aren’t guaranteed? My recommendation is build up your knowledge of prospecting over 2 or 3 years before investing in bigger toys. This way once you’ve established a good, possible gold source, you might feel it’s now time to go for higher production. Large scale industrial miners work in much the same way. I have a good friend who suction dredged for a few years on a creek. After taking out numerous ounces of gold, he made a decision to go bigger. From there he bought a small D-6Cat to feed a sluice box, then eventually he added a backhoe. Today he has a D-9, a bigger backhoe and a dragline. He’s been seriously at it for over 25 years. In the off season he has another job to support his “sickness” called “gold fever.” Gold found by a prospector I’ve met a few folks who complained: “Yeah, I went out for a couple hours, and didn’t get a thing. There’s nothing out there!” He immediately was very skeptical there was any gold at all out there.” I said that was fine. There’ll be more for the rest of us! I told this fellow, a couple hours does not do the trick. You have to work at it. It won’t jump up into your pan, and no one will tell you exactly where it is because they don’t know themselves where it is exactly. We have an idea, but we can’t always pin point it. Most of the time we walk right over it. I remember an old prospector from up on the Yukon River was once asked where he kept all his gold, to which he replied; “Its in a safe place in the creek!” He knew he could dig it out anytime he wanted to, but he had to make the effort. No one would get it for him. He took out enough gold to survive on most of his life. It was his lifestyle and sole occupation. Finally, recapping everything, I can’t stress enough: 1 - Start small, then gradually increase your devices to accommodate your potential production. You might advance from a sluice/gold pan to a nugget detector. You might eventually obtain all the tools of the trade, short of buying a bull dozer. The bull dozer purchase would probably indicate you’re pretty serious or you’ve got money to blow! 2 - Enjoy this endeavor. If you don’t enjoy it, get out of the business. You probably should not have gotten into it. 3 - There’s no room for discouragement. If you’re easily disappointed then prospecting is probably not for you. 4 - Expect to work hard at it. Be patient. Patience is a virtue. You will put in time of no rewards, but when they come, it’s worth it all. 5 - Don’t get greedy. If you hit it big, a few ounces here and there or bigger, consider it your much deserved reward. 6 - Don’t mortgage the farm. Never, never do this! I’ve known miners to put all their eggs in one basket and they all cracked! Unless you like living in tents on the edge of town, never gamble with your stability. 7 - Enjoy prospecting. Its one of the most fascinating occupations I can think of. What better way to enjoy the outdoors, splash around in cold water on hot days, explore old ghost towns, collect rocks, view big game, there are folks that would give their right arm to do this. A word of encouragement to those in search of gold: Practice patience, be optimistic. Always learn from your mistakes and always keep enough bug dope in your pack! by Ron Wendt 2005 Note from Steve Herschbach - Ron was a dear friend who left this world too soon. He donated this article for use on the website not too long before his health finally failed. We all miss you Ron! R.I.P. Ron Wendt 1956 - 2007 From the obituary: Ron Wendt was born April 24, 1956, in Fairbanks, in the Territory of Alaska. He was raised on his family’s homestead on Chena Hot Springs Road outside of Fairbanks and his father’s mining claims in the Circle gold fields. He developed an early interest in Alaska history by exploring ghost towns and mining camps and talking with old-timers from the gold rush era. Ron worked as a gold miner, newspaper reporter, photographer, college instructor, construction worker and custodian before starting his own publishing business, Goldstream Publications, in Wasilla. He wrote about gold rush history, modern day mining and prospecting, and many tales of Alaska. He was a member of the Alaska Miners Association, an avid baseball fan and loved to travel the roads of Alaska with his wife, Bonnie.
  5. 9 points
    There are a few key things to know about headphones for use with metal detectors. The most important thing is to know that some detectors operate in mono, and some in stereo. If you mismatch headphones you can end up with audio in one ear only, or none at all. In fact, this has happened to me. I took my White's DFX out to do a little detecting, and grabbed an old pair of Fisher Phones I had around, and when I got out I found the phones would not work on the DFX. So most detector phones have a stereo/mono switch, or are specially wired to work either way. Make sure your headphones match your detector for stereo or mono operation. But best case is to only use headphones that can do both so you can use them with any detector. You never know when they might get put to use on a different machine. In a situation where you are determined to use a mono headset on a stereo detector or vice-versa plug in adapters can be purchased at most electronics supply houses. 99% of the detectors out there have a 1/4" headphone plug, but many generic headphones have a 1/8" plug. Sure, you can use an adapter, but it just adds a weak spot in the system. So get a 1/4" plug unless your detector is one of the rare 1/8" models. Again, pay attention to the mono versus stereo issue. The good news is that if you make a mistake there is almost always an adapter that will fix the problem but it is best to try and get the correct match. Does your detector have a volume control? Many do not. It is best to buy headphones that have their own volume controls, so you can use them with detectors that do not have a volume control. Again, you never know when you might switch detectors. Ohm matching can be important, and generally higher ohms is better. This is not always true however and some detectors do work better with lower ohm rated models. It is usually easy to determine what the headphone ohm is but almost impossible to know what the detector rating is. I therefore recommend that you should have your detector in hand and be trying the headphones before you buy them instead of going by specs on this point. Things to look for: 1. How do they sound? Are targets sharp and clear to your ear? If not, you can now pass on this set and try another. Different headphones match up with different machine and different ears in such a way that nothing short of trying them can sort this point out. They either sound good to you personally, or they do not. It does not matter what your friend likes. Some detectors allow you to change the pitch from high to low. Try different pitches with your detector to see what sounds best. How do faint targets sound to your ear? People have different frequency responses, some like low tones and some high, and the type of speaker wired into the headphone can make this sound vary a lot. Get a set of headphones that make faint signals as clear as possible to your particular ear. 2. Assuming they sound good, how adjustable is the volume? A good match will give you the ability to fine tune the sound with the volume control on the headphone. In other words, the volume control will have some range. If you have very high ohm headphones and use them on a high volume machine that has no volume control, the headphones may be so loud you have to set the volume on the headphone nearly off. And then tweak it within a fraction of a turn. Some headphones are too powerful for some detectors! The volume control should run from off at one end and too loud at the other, with lots of adjustment in between. 3. How many volume controls are there? Some people like two, one for each ear. This can be great if you have poor hearing in one ear and need to compensate. I personally prefer a single control that works both ears at the same time, so I do not need to fiddle two controls. So this is a personal preference thing, but your headphones should have one or two headphone volume controls. A note on setting your headphones. Turn the detector volume all the way up, if it has a volume control. Turn your headphones all the way down, then turn on your machine and wave it over a large metal item. Turn the headphones up until the loudest sound you will get over a large item is not so loud as to damage your hearing. Now, set the threshold sound on your detector for a faint buzz. You should now be able to hear faint variations in the threshold, but going over a 55 gallon drum will not damage your hearing. Metal detector headphones showing 1/4" 90 degree jack, coiled cord, padded muffs, and dual volume controls 4. How well do the phones exclude outside noises? Normally, get a set of headphones that will exclude outside noises like running water, wind in the trees, or anything else that might distract you from the detector sounds. Sometimes it may be advantageous to use phones that let you hear outside noises, like in bear or snake country. Or maybe in real hot climates bulky units get too warm. But from a pure detecting standpoint sound excluding headphones are best. Earbuds are perfectly acceptable however for quieter locations. 5. How well do the headphones fit and feel? Imagine they are going to be on your head for 12 hours. Something that feels good initially can feel pretty bad in a few hours. Beware of headphones that are too tight or that have too little padding. I prefer phones that completely cover my ear and seal to the side of my head. I do not like the kind that squash my ear but people's preferences vary. Make sure your headphones are comfortable for long hours of use. 6. How tough do the headphones appear to be? This can be hard to gauge sometimes, but in general avoid anything that looks to have cheap construction. The number one failure point is the cord, so make sure it is strong and well anchored so it cannot pull out. Headphones that feature a 90 degree plug are often desired to reduce strain and prevent the plug from pulling out due to a simple tug on the cord.Some top end models feature replaceable cords so you can carry a spare. I prefer to simply carry a complete spare set of headphones. 7. Finally, be aware that the newest metal detectors are coming equipped with built in wireless headphone capability. Early versions have either been standard Bluetooth, which is too slow, or some faster proprietary method. Standard Bluetooth has a significant lag between detecting a target and the actual audio response heard in the headphone which is bothersome to most people. The problem with proprietary is that you are stuck with very limited options as to headphones. The best option currently for most people is aptX Low Latency (aptX LL) Bluetooth, which is fast enough that most people are satisfied with the speed, and options abound in the choice and style of headphones. To sum up, if buying headphones at Big Box Inc. at the least you'd probably want a set with a stereo/mono switch, 1/4" jack, and volume control/controls just to make sure it will work on most any detector. But remember that headphones are like tires for an expensive sports car. They are one of the only important items on a detector you can customize for optimum performance, the other being search coils. Finding the set of headphones that is just right for you can make a real difference in detecting success, so it deserves some effort in getting the right set. This is where a local dealer with a good selection who is willing to let you try them all out on your detector can really help you out. ~ Steve Herschbach Copyright © 2009 Herschbach Enterprises
  6. 7 points
    This page has links to a collection of online "books" about prospecting and metal detecting subjects of interest. Most of these were actual printed books or brochures that are now available as html or pdf documents. In the case of pdf documents especially you can download and save these creating your own library of essential information. Many of these are out of print and hard to find so we are very lucky they are being scanned and made available on the internet. Metal Detecting How Metal Detectors Work by Mark Rowan & William Lahr - Originally published by White's Electronics as a booklet P/N 621-0395. Basic but rather technical information on how induction balance and pulse induction metal detectors work. Metal Detector Basics and Theory by Bruce Candy - Bruce is a co-founder of Minelab and the man behind their most advanced designs. This information delves into much greater detail than the above link and has many more illustrations and diagrams. Metal Detecting Terminology - Metal detecting terminology and definitions, with an emphasis on Minelab technology wording and descriptions. Gold Prospecting with a VLF Metal Detector by Dave Johnson. Dave is the Chief Designer for First Texas Products and has been involved in designing most of the VLF gold prospecting detectors sold over the last 30 years. This is an excellent primer on using VLF detectors to prospect for gold. The History of Metal Detectors, with Emphasis on Gold Prospecting from First Texas (Bounty Hunter, Fisher, Teknetics) by Dave Johnson. A talk given to the El Paso Chapter of the GPAA February 12, 2008. Metal Detecting Technologies for Gold Prospecting from First Texas (Bounty Hunter, Fisher, Teknetics) by Dave Johnson. A short essay of key technologies for gold nugget detecting. Understanding the PI Metal Detector by Reg Sniff. An excellent, understandable primer on pulse induction metal detectors. Metal Detector Information - Get lots of great answers to basic detecting questions along with info and field reviews of Tesoro detectors. Common Questions About Metal Detecting from White's Electronics. Recommended Recovery Methods by Robert H. Sickler - Do not damage the turf! Fisher Intelligence 5th Edition by Thomas Dankowski. Thought provoking articles on aspects of metal detecting not often talked about. Advanced Nugget Hunting with the Fisher Gold Bug Metal Detector by Pieter Heydelaar and David Johnson. This out-of-print book is a good basic text on nugget detecting. Although it uses the original Fisher Gold Bug as an example the information applies to most nugget detectors. Part 2 by David Johnson is an excellent primer on hot rocks. The Painful Truth by Thomas Dankowski - There is more good stuff left to be found but hidden from current technology - read why. A follow up to Dankowskis classic Beneath The Mask article. Head-To-Head Comparison Testing by Thomas Dankowski. It is not as easy as it looks! Why people get different results testing metal detectors, and how to do it properly. Halo Effect & Related Ground Oddities - from Fisher by Dave Johnson. An explanation of factors that can possibly enhance detector depth - myth or reality? Steve's Guides - Articles about basic metal detecting and gold prospecting subjects. Metal Detector User Guides & Catalogs - User guides, catalogs and brochures from various manufacturers. ads by Amazon...
  7. 7 points
    The secret to the Minelab GPX series is thoroughly understanding the timings and when to use each one. Timings are variations of the basic pulse induction technology at work in the GPX series that gives you far more flexibility than exists in other pulse induction detectors. Unfortunately this extra flexibility also adds complexity, and so it is not unusual that some people may not be using the optimum settings in many cases. It is very important when investing in a Minelab GPX detector to take the time to read the manuals and study until you fully understand what the settings do and how to adjust the detector for the best performance. Otherwise you will not be getting all the potential out of your investment. The chart below shows the timings and what GPX models they are available on along with a general description. The descriptions are from the owners manuals that are available by download at the bottom of the page. In general you should always use timings as near the top of the chart as possible, with the exception of the Salt settings. Those are for alkali flat and salt water beach areas only. Using timings designed for more mineralization than is actually required may result in less depth on desired targets. Imagine the timings as another sort of ground balance setting. Low mineral settings are more powerful than high mineral settings and should be used whenever possible. Some confusion is the result of the timing names. Some people assume the Fine Gold timing is best for fine gold. This does make a sort of sense, but the fact is Fine Gold is just better than other high mineralization timings on smaller gold. In milder ground Sensitive Extra will obtain better results on small shallow gold. It is also very important to know that some timings work better with one coil type or the other. Minelab GPX Timings Chart Little or No Mineralization Coin/Relic (GPX 5000 ONLY) Coin/Relic is for use in lightly mineralized soils including many beaches and loamy soils. It offers maximum detection depth on a range of target sizes, significantly greater than any other timings. However, if the ground is any more than lightly mineralized, the detector may not ground balance properly. On ocean beaches containing significant quantities of black sand, better results may be had by using Normal or Salt settings. Mild Mineralization Sharp (GPX 4500, 4800, 5000) Sharp is similar to Normal but creates a more powerful detection field. It is capable of an improvement in depth, but is more susceptible to interference and will increase the severity of false signals in difficult grounds. This timing is best used in quiet conditions and can work well in combination with Deep Search Mode with a reduced Rx Gain setting. Sharp is an excellent tool for pinpointing faint signals due to the very "sharp" signal response. Sharp will work best with DD coils in most gold field locations. Medium Low Mineralization Sensitive Extra (GPX 4000, 4500, 4800, 5000) This timing may increase the signal from certain hot rocks near the surface, but can actually help smooth out the Threshold in certain ground types, particularly with Double-D coils. In mild ground conditions Sensitive Extra will provide the best signal response on a small, deep target. Medium Mineralization Normal (GPX 4000, 4500, 4800, 5000) Normal gives you the best performance on a wide range of soil conditions, and it will provide the best depth on a wide variety of target sizes. It works particularly well with the supplied 11" DD search coil for general detecting. You should always use Normal in new areas where you are unsure of the soil mineralization and the depth of targets. Medium High Mineralization Salt Coarse (GPX 4000, 4500, 4800) The effect of alkaline salt mineralization is vastly different to the effect of ironstone and mineralized clays. Normal should be tried first in these areas, but if the Threshold is too unstable then better performance will be obtained in Salt-Coarse. Using the Salt-Coarse timing may result in a loss in signal response to smaller targets. However, the response on larger items remains relatively unaffected and ground noise is usually minimized. Medium High Mineralization Salt/Gold (GPX 5000 ONLY) Provides the best signal response on small to large gold in salt saturated and mineralized ground conditions. It should work well on dry inland salt lakes, high salt concentrated goldfields, and mineralized saltwater beaches. Extremely salt saturated soils may still need to be searched with the coil switch in Cancel (using a Double D coil). High Mineralization Fine Gold (GPX 5000 ONLY) Fine Gold is sensitive to smaller targets in highly mineralized ground. It provides a sharper signal on small gold compared to Enhance, and improves the detectability of rough/flaky gold and specimens, while ignoring most hot rock signals and false ground noises. Shallow, highly mineralized ground where gold has been found previously should be re-examined with Fine Gold, and best results will be had by using the optional 8” and 11” Commander Monoloop coils. Note: Sensitive Extra will provide superior results on small gold in milder ground. Very High Mineralization Enhance (GPX 4500, 4800, Improved in GPX 5000) Runs quietly in most heavily mineralized, variable and "hot rock" infested grounds using a monoloop coil. It is more sensitive and detects deeper than Sensitive Smooth but can be slightly more affected by severe ground mineralization. Severe Mineralization Sensitive Smooth (GPX 4000, 4500, 5000) Sensitive Smooth is optimized for an improved response on smaller, shallow nuggets in severe soils. There is a loss of depth on bigger targets; so you should not use this setting when seeking out large, deep nuggets. Sensitive Smooth is best suited for use with monoloop coils in difficult soils. It eliminates most false signals from hot rocks, and ground mineralization, whilst retaining excellent sensitivity to small targets. The example below shows three common timings and where they should be used. It also highlights why using the wrong timing for the conditions can result in missed targets. Minelab Mineralization and Timing Example The following chart illustrates the procedure for finding the correct timing for each situation. In general, always start with the Normal timing. If the detector is stable and quiet, try timings on the left - Sensitive Extra, Sharp, or in rare cases, Coin/Relic. If ground noise or hot rocks present problems in Normal, then try timings on the right - Fine Gold, Enhance, or Sensitive Smooth. Salt settings should generally only be used on alkali ground (salt flats) or salt water beaches, but may have applications in other ground. The goal is always to find the most powerful setting that allows for stable operation. Each timing can be adjusted within certain parameters, primarily through the use of the Gain and Stabilizer settings. Adjusting for a lower Gain, for example, may be preferable to going to a less powerful timing. Minelab GPX Timing Selection Chart - Click on image for larger version Finally, each timing may work best with a certain type of coil (DD or Mono) and the timings have varying level of resistance to Electro Magnetic Interference (EMI). The matrix below attempts to show which timings offers which benefits and strengths/weaknesses. Minelab Timing Coil EMI Matrix - Click on image for larger version The simple chart below can be printed out and taped or glued on your detector shaft as a reminder in the field as to which timing may be best. Click on the image to download a large version. Minelab Timing Decal - Click on image for larger version Minelab GPX 4800/5000 Instruction Manual Download Here Minelab GPX Series Quick Start Guide Download Here Minelab GPX 4800/5000 Product Brochure Download Here Minelab Commander Coil Brochure Download Here Minelab GPX 4500 Instruction Manual Download Here Minelab GPX 4000 Instruction Manual Download Here ~ Steve Herschbach Copyright © 2011 Herschbach Enterprises
  8. 6 points
    What is metal detector “autotune” or automatic tuning? Not automatic ground balancing or automatic ground tracking. Autotune is something so common now it is taken for granted, but it is a key feature when considering how detectors work, especially those designed to work with a faint threshold sound, like most nugget detectors. Prior to the 1980's most detectors had to be ''tuned''. You held them at a fixed height over the ground and manipulated a ''tuner'' until you got a bare threshold sound. A very faint sound you could barely hear. An increase in this sound meant you had a target. You could hold the detector over the target when you found it, and the increase in sound held steady. When the detector was moved off the target, the sound went away. No motion was required to get a signal, and so this mode of detecting is referred to as the ''non-motion mode''. There were two problems. First, the detectors of that day ''drifted''. The faint sound you set would either get louder or fainter. As the machines adjusted to temperature differences, or as the batteries ran down, the threshold changed. It did so rather rapidly, and so you constantly had to adjust the faint threshold setting manually to keep it on that vital edge. Also, the machines of the day could not ground balance. So if you raised the coil you got a false signal. If you lowered it the detector ''detuned'' and the threshold went away. Faint targets were lost. This was mostly an issue with small depressions in the ground. If you had the detector tuned to a fine edge, going over even the slightest depression gave a false positive signal. What I did myself was hold the detector an inch over the ground, tune it, and then lower it to the ground. This slightly detuned the detector and gave up the fine edge, but eliminated false signals from small depressions in the ground. Early 1970s "Mineral - Metal" ttuner control The first solution to this issue was push-button retune. If the faint threshold you had set got too loud or went away for any reason you just pushed a button, and you went right back to the original threshold setting. It was a great advance in its day, as pushing a button was much easier than turning a knob to get back the correct threshold. The detector “remembered” where you set the threshold, and a push of the button instantly returned it to where you had previously set it. This also made for better pinpointing of targets, as you could get close to the target, hit the button to detune the detector, and then zero in on the sharpest signal. Some detectors today still feature this form of ''non-motion pinpointing''. The next advance was electronic. The detector took note of the threshold you set, and circuits attempted to maintain the same threshold level. Since the original idea was to ''tune'' your detector, autotune was born. The detector automatically tuned the threshold. But a side effect was that if you held the detector steady over a target it was ''tuned out'', as the machine sought to return to the ideal threshold level. You had to keep the coil moving over the target to hear it, and so the “motion mode” was born. The original Gold Bug is the best example of all this. If set in the ''non-motion'' mode you can hold the detector over a target and get a louder sound that does not fade away. The closer you are to the target, the louder the sound. Great for pinpointing. But if you set the Gold Bug in this mode, it drifts. The threshold sound tends to get louder and louder. A button is provided to retune the Gold Bug to the original threshold sound. You must hit it about once a minute. The Gold Bug also has an ''autotune'' mode. This is the mode you would normally use. The detector now reads the threshold setting and keeps it steady. The side effect is that if a target is held steady under the coil, it is ''tuned out'' rapidly. The coil must be kept in motion over the target to get a signal, otherwise the autotune circuitry adjusts it out. It does not matter what causes the threshold to vary. The circuitry just attempts to keep it steady. Nothing is being tuned other than the threshold sound. Fisher Gold Bug controls, with autotune in lower left Various detectors were introduced with this feature. What varied was the rate at which they retuned. A slow retune meant that the detector would not adjust as rapidly to variations in the threshold sound. The slow retune had less of a tendency to ''tune out'' small targets or very deep targets. A fast retune was more forgiving of variations in the way the detector was operated, in particular as regarding the distance of the coil over the ground and false signals, but is more prone to tuning out very small or very deep targets. Whatever retune rate is chosen, it is a compromise. And what works well in one location does not work so well in another. When nugget detecting became popular a new variable was introduced. Ground mineralization, and more importantly, variations in ground mineralization, was something coin hunters rarely had to deal with. It was something a nugget hunter commonly encountered. Detectors at this time developed the ability to ground balance, or adjust out the ground effect that caused early detectors to give a false signal if the distance over the ground varied. Depth of detection dramatically increased. The ground balance control initially was a manual control, and so could be set for a certain ground condition. Any change in the ground mineralization tended to produce false signals. Autotune once again came to the rescue, as evidenced by its use in the original Gold Bug model. Units with a slow autotune had fewer tendencies to tune out small gold nuggets, or very deep gold nuggets. The downside is they had to be operated very slowly to allow the autotune to keep up with ground variations. Units with a fast autotune could handle variations in the ground conditions better, but had more of a tendency to tune out small or deep targets. Overall depth was usually decreased with faster autotuning but ease of operation increased. Another split in the technology came along. Many detectors, especially coin detectors, opted for a “silent search” mode. This mode eliminates the threshold sound entirely, very much like taking a detector with a threshold control and turning the threshold down until it cannot be heard. This makes for a quiet machine and became the preferred mode for many coin detectors. But it gives up a fine edge and so top performing units continued to offer a threshold control. Detectors that are silent search units do not need an autotune circuit. You can test a detectors autotune rate on detectors that have a threshold setting by holding a coin under the coil, and noting how fast the threshold adjusts back to its original level. This can vary from a couple seconds to almost an almost instant adjustment. An interesting side effect of autotune is ''overshoot''. If the detector is swept to one side and encounters a target, it attempts to ''tune into'' the target. If the target is a ''positive'' target, in other words the threshold increases, then the autotune circuitry immediately reads the increase and attempts to adjust lower. As the coil passes the target, there is a brief moment of silence as the autotune now has to turn around and increase the threshold back to its original level. In practice, you normally do not hear this. You hear the increase in tone, but not the decrease that follows. The target goes ''beep-beep'' as you swing back and forth over it. The ''beep'' is centered over the target. Move the coin back and forth under the coil and you will hear the sound. Now hold the coin under the coil until the threshold steadies, then remove the coin. The machine will go silent for a short period, again depending on how fast the autotune circuit is. However, if the target is an iron mineralized rock, most commonly a rock with a high magnetite content, then the threshold ''detunes''. The threshold is reduced and goes silent. So as you pass over the hot rock the threshold sound goes silent. The autotune circuit attempts to adjust by raising the threshold sound. But at this point you have passed over the ''negative'' target. A distinctive ''boing'' sound results since the threshold sound is now too high, and the autotune immediately attempts to adjust back down. The ''boing'' sounds occur to each side of the target as you sweep back and forth over it. The quiet spot, or ''null'' at the point between the opposing boings indicates the actual location of the target. To reiterate, autotune creates two types of signals. A beep-beep signal with the beep centered as the coil sweeps over it in both directions. Or a boing-boing signal, with the apparent target dancing back and forth as the coil sweeps over it. The null between the two boings is the actual location of the target, usually a hot rock. When White's introduced the Goldmaster V/SAT it featured "Variable Self Adjusting Threshold" or V/SAT. Self Adjusting Threshold is White's term for autotune. It is a more appropriate term as it explains what is really happening. People tend to confuse autotune with automatic ground balance. Unfortunately, White's fondness for acronyms is such that most people do not know what SAT or V/SAT stands for. The latest acronym is iSAT by Nokta/Makro for "Intelligent Self Adjusting Threshold". White's GMT Variable SAT Control The Goldmasters are the only nugget detectors that allow you to vary the rate at which the threshold readjusts itself via a knob - anything from very fast to very slow. This allows for more control in varying situations. In general, use the lowest SAT setting that allows for smooth operation. As ground variations increase, setting a higher self adjusting threshold can be beneficial. At low settings, the coil can be swept slower. High settings demand a faster sweep rate. The Gold Bug 2 has a “High”, “Normal”, and “Low” mineral modes. These are actually three preset autotune adjustments, with Low being the slow autotune and High being the fastest. Normal of course is in the middle. With the vast majority of the nugget detectors you have no ability to vary the autotune rate. A few programmable coin detectors offer the adjustment but usually relate it more to sweep speed so the detectors can be set for a slow sweep speed or a fast sweep speed. To sum up, it is very important to know how fast your detector is autotuning. If it has a fast autotune and you move the coil too slowly, you will lose very small and very deep targets as the machine tunes out the faint signal before you hear it. Conversely, if your detector has a very slow autotune rate (rare these days, but common on old detectors like the Compass Gold Scanners) then moving the coil too quickly will also cause very small or very deep targets to be lost. The best way to observe this is to bury a target, and sweep the coil over it. Go real slow, go real fast, and try something in between. You will find a certain speed will produce the loudest and sharpest signal. Going much faster or much slower will muffle the target. Detector engineers try to shoot for a normal sweep speed, and newer detectors are much more forgiving than older units. But sweep speed does impact the performance on many detectors. One thing that sets the pro apart from the novice is that the pro keeps the coil moving at the optimum rate that produces the best signal. When autotune is combined with auto ground tracking, this awareness of optimum sweep speed is even more critical. As a rule single frequency machine can handle faster sweep speeds. Multi-frequency and pulse induction (PI) detectors benefit from slower sweep speeds. People used to one type of detector often have a hard time adjusting. It is very common for operators of single frequency fast sweep detectors to swing PI detectors far faster than they should, resulting in significant lost performance. Do not be one of those people. Experiment with your detector to find the optimum sweep speed, and in the case of the few machines that allow for adjustments, experiment to see how slower and faster settings affect the performance. It can make all the difference between finding that gold nugget and missing it. ~ Steve Herschbach Copyright © 2010 Herschbach Enterprises
  9. 6 points
    This is not intended to get into every nitty-gritty little detail, but instead is a brief overview for those unfamiliar with the Minelab Pulse Induction (PI) detectors. The units released so far are the SD2000, SD2100 (and V2 variant), SD2200D (and V2 variant), GP Extreme, GP 3000, GP 3500, GPX 4000, GPX 4500, GPX 4800, and GPX 5000. The Minelab SD2000 was the first of the series, a genuine breakthrough in metal detector technology. It is the basis on which all the other models were developed. It was the first true prospecting pulse induction metal detector and it had a major impact in the Australian goldfields for which it was designed. The main drawback was a definite lack of sensitivity to nuggets weighing under a gram or two. The SD2100 and SD2100v2 are fairly simple manual ground balance units that refined the SD2000. The frequency could be manually adjusted to avoid interference from outside sources, such as a nearby detector. The SD2200d and SD2200v2 offer automatic ground balancing or a fixed/locked ground balance. They also introduced an iron disc feature of dubious reliability, audio boost, and automatic frequency offset. The GP Extreme offered enhanced sensitivity to small gold that was lacking in the earlier units. Much of this came about from Minelabs patented dual voltage technology (DVT) which was introduced with the GP Extreme and is featured on all subsequent models. There were quality control issues with the unit however and so performance varied on GP Extreme detectors. The GP 3000 is essentially just a refined GP Extreme and the GP 3000 performance is more consistent between units than was seen in the GP Extreme. Threshold smoothness was improved to be less erratic. The GP 3500 offered manual frequency tuning to help eliminate electrical interference and three tracking speeds for the automatic ground balance system. A button was added to the handle to allow for easy switching between the manual and automatic ground balance modes. The GP 3500 was the last of the analog models in the series. Where it all started - the Minelab SD2000 "Super Detector" The GPX-4000 was a break from the past, going to a digital control system. This allows for more adjustments but also more complexity. The GPX models can attain smooth thresholds on par with the best VLF units. A major advance is in the form of various optional "timings" that allow the detector to be customized for various types of ground mineralization and hot rocks that might be encountered. The GPX-4500 is a basically a refined 4000. A pattern develops by now in that Minelab tends to make a major model revision, then follow up with another model that is just a refinement of the earlier unit. Model releases come about every two years with major changes about every four years. The Minelab GPX 4500 was extremely popular and the next model release was delayed to the point that two models came out. The Minelab 4800 was intended as the next release, but before it hit the market developer Bruce Candy came up with a couple new refinements different enough to warrant yet another model, the GPX 5000. The 4800 therefore became a sort of "non-model" as most dealers and users focused on the GPX 5000 as the new top-of-the line detector. The main change is a wealth of new timings allowing the GPX 5000 to get optimum performance in many varied ground conditions. The new Fine Gold timing in particular offers the ability to pull gold out of ironstone hot rocks that previous models missed. Minelab SD2200v2 pulse induction (PI) metal detector I disagree with those that say you can get more depth on large gold from earlier SD units than from the latest models. Having used all the models the largest improvement I've seen over time is vast improvements in threshold stability and the ability to adjust for more varied circumstances. It may be that in a particular location an SD will do just as well as a GPX. But not where I hunt. My SD units all had the famous Minelab "warble" whereby the threshold constantly wavered. This meant that small nuggets or very deep larger nuggets had to give enough of a signal to break through the waver. A far cry from listening to a rock solid threshold for the faintest whisper or "break" in the threshold. You can get just such a rock solid threshold with the GPX units. It is not that the GPX goes deeper, it is that you can hear nuggets you would miss with an SD as they could not be discerned as clear signals. More important on my ground was that my SD units simply could not tune out the intense magnetic basalt cobbles we have to contend with. The cobbles give a faint gold hit. So you either dug them all (impossible) or simply ignored the faint signals. But some of them were small nuggets or very deep larger nuggets. When the GPX arrived at my property I saw so many more small nuggets and deeper large nuggets come out of areas well hunted to the point of being "hunted out" that it was obvious the GPX had a significant edge. I'm not talking a nugget or two - I'm talking pounds of gold. The new GPX timings can allow for a clean solid threshold in areas where that was impossible with earlier units. Those that do not hunt such locations do not see the value in a GPX. Those that do know what I'm talking about. There is no way I'd go back to using an earlier model than the GPX-5000 by choice. Minelab GPX 5000 - pulse induction metal detector technology refined It should be noted is there are quite a few people modifying older SD units to get better performance on par with later units, and I'll admit these modified units are a wild card. Some swear by them and I'm not going to doubt them. But modifying older detectors is beyond where most people want to go so I think there is little doubt these units will only see use by a certain hardcore group of knowledgeable detectorists. The GPX 5000 has refined the platform to the point where realistically it is hard to think of ways the unit can be improved from a detecting standpoint. The only obvious deficiency is the ferrous discrimination system. While it does have its uses the ferrous discrimination on the Minelab PI detectors is notoriously unreliable and only to be used when absolutely necessary. Its use will inevitably cause gold nuggets to be left in the ground, misidentified as iron or steel. This area has been so resistant to improvement, however, that I look more for advances in the physical package as my most desired area for improvement. The general control box and rod design with backpack mounted battery has not changed since the original SD2000. Development of a GPX type detector housed in a package more reminiscent of the new Minelab CTX 3030 would be a major advance in the usefulness of the lineup with no actual change in performance aspects of the electronics. It has been well over two years since the GPX 5000 was released, and so I do not think it will be too long before we see what Minelab has in store next for nugget hunters. ~ Steve Herschbach Copyright © 2013 Herschbach Enterprises P.S. When I wrote this article in 2013 I had no idea that two more years would pass before we saw what Minelab had up next - the Minelab GPZ 7000. It turned out that Minelab also thought the GPX 5000 had taken the pulse induction as far as it could go, so the GPZ 7000 features new ZVT technology. The biggest surprise for me however was that Minelab may have paid attention to my "GPX in CTX housing" comment above. That may or may not make some people happy! And the GPX 5000? Still in production as the top-of-the-line PI from Minelab!
  10. 5 points
    The Fisher Gold Bug Pro was released in 2010 and is still in production. It is the final version of a series of new digital Gold Bug releases intended to replace the older analog Gold Bug models. The easiest way to tell the new Gold Bugs from the old Gold Bugs is that the new models sport a prominent digital readout. The model is also marketed separately by First Texas, Fisher's parent company, as the Teknetics G2. The G2 has a different rod and handle assembly and comes standard with the 11" elliptical DD coil for slightly more money. The Gold Bug Pro comes standard in three versions - with a 5" round DD coil (actually 4.7" diameter), or with the 7" x 11" elliptical DD in which case it is called the Fisher Gold Bug Pro DP. Finally, there is a dual coil package the includes both the 5" round DD coil and the 5" x 10" DD coil. In addition to the three coils mentioned here DeTech markets the 13" Ultimate DD coil for the G2 that will work on the Gold Bug Pro. For more information see the Guide to Different Versions of the Fisher Gold Bug. I have come to rely on the Gold Bug Pro as my general purpose prospecting detector for when I want a unit that can handle trashy areas. I appreciate its light weight and simplicity in getting the job done. I prefer to run the detector in all metal mode for the best depth and sensitivity. The nice thing is that the meter always displays possible target ID information to help make digging decisions without having to switch or toggle to another mode. This is far more efficient in the field not to mention wear and tear on switches. I prefer the 5" x 10" DD coil for general use - it is too bad Fisher does not sell the Gold Bug Pro with that as the stock coil. The only way you can get it is as a package deal or as a separate accessory item. The only thing I wish was that instead of displaying the ground phase as a large number while in all metal mode the Gold Bug Pro instead displayed the possible target ID number. The target ID is displayed on a small "racetrack" display above the ground phase number. I rarely if ever need to know what the ground phase is but I constantly refer to the target ID. Hopefully this will be addressed in future versions. Fisher Gold Bug Pro - Gold Bug DP variant (7" x 11" DD coil) I normally hunt in all metal. The detector hits all targets with the same audio signal except the stronger the target, the stronger the signal. There is a little "speedometer" target id readout in all metal above the big ground phase reading and so after hearing target I work it and eyeball the reading. If you get no target id it is target deeper than disc can hit (all metal prospect mode goes deeper than discriminate mode) so dig until you get target id or target. You need to decide on what target id to dig and what to pass. In theory all 40 and above is non-ferrous so in theory just dig all 40 and higher. Reality is small gold or very deep gold can read iron. I usually opt for digging some iron, and so depending on types of ferrous trash and ground mineralization the actual number I choose may be 35-39, usually 38. Then, and this is key, work the target. If the number bounces even once to or above your chosen break point, dig. The numbers bounce around, and if they consistently read at or below your chosen reject number, for example 38, if the number is always 38 or lower pass it up. If it bounces even once to 39 or higher dig it. Again, number picked depends on actual ground conditions. Start lower, maybe 35, then adjust upwards after digging targets. As long as you are not digging too much ferrous stay put but is too much digging adjust higher. VLF discrimination can and will lie on small or deep gold so better conservative and digging at least some ferrous than leaving gold. Fisher Gold Bug Pro with 5" x 10" elliptical DD coil Ok, let's assume too much trash, to many signals to analyze each one. Go to disc mode. Immediate depth loss! But now we can set target id audio break point. The unique tone disc system has three tones, mid tone, low tone, and no tone (target rejected). You can move range but it is not totally adjustable. The low tone area compresses as the disc is set higher. If you set low tone cutoff at 30 all target below 30 make no sound at all and all passed up. You never know they are there. 30 to about 55 will be low tone, meaning most gold and small ferrous, 56 and above will be mid tone, usually brass but maybe big nuggets. There is no high tone on the GBP. You can adjust this potential gold tone range to a certain extent. Set at 35 and nothing below 35 reports, 35 to maybe 60 (doing this from memory so may be off a bit on the numbers) will be low tone, above 60 mid tone. Or if trash really is bugging you set at 39 so only 40 and above beeps. But because some targets read mostly ferrous but bounce non-ferrous at times it is a fuzzy choice. If you set for 40 and above and small nugget reads 38 on first pass, you miss it and never know it was there. At the end of the day it depends on trash level and how much target analyzing you want to do in the fuzzy zone. Most small nuggets actually read around 50 but again all depends on gold size, shape, purity, ground mineralization and other factors. ads by Amazon... Lots of nuance in what is a deceptively simple detector. The more I use it the more I appreciate it. In all metal with 11" x 7" DD it approaches PI depths on most average size gold in moderate to mild ground. I very much like having the dual ability of hunting in all metal while having visual target id. No toggling back and forth. I not only use the Gold Bug Pro for prospecting but for jewelry detecting. It is a not the best coin detector in the world but does well, especially in trashy areas with the little 5" coil. All in all a great little machine, one I can swing high and low all day long with little fear of arm strain. I highly recommend the Gold Bug Pro for anyone looking for their first nugget detector or for old pros like myself wanting something light, simple, and effective. Official Fisher Gold Bug Pro Page Download the Fisher Gold Bug Pro Instruction Manual Here Guide to Different Versions of the Fisher Gold Bug Forum Threads Tagged "fisher gold bug" First Texas (Fisher) Metal Detectors Forum Fisher Gold Bug Pro Technical Specifications* Internet Price Basic Gold Bug $499 / Pro $549.00 (5" coil) or $599.00 (7" x 11" coil) Technology Induction Balance (IB) Transmit Frequency 19 kHz Autotune Mode(s) Pre-Set Slow Motion Ground Rejection Manual Touch Pads with Grab Function Soil Adjust No Discrimination One turn control, Visual ID, Tone ID Volume Control No Threshold Control One turn control Tone Adjust No Audio Boost No Frequency Offset No Pinpoint Mode Yes Audio Output 1/4" headphone socket & speaker Hip Mount No Standard Coil(s) Choice of 5" round DD or 7" x 11" DD Optional Search Coils Many accessory coils available from Fisher and aftermarket Battery One 9V Operating Time 15 hours Weight 2.5 pounds with 5" coil Additional Technology Continuous ground phase readout Notes Also available as 5" plus 10"x5.5" DD two coil package for $749 *Notes on Technical Specifications - Detailed notes about the specifications listed in this chart.
  11. 5 points
    This discovery was made earlier in 2016 but I did not get around to publishing details about it until now. I was detecting near some small hydraulic pits in California and wandering around in the area below one of the pits. At first I thought I was on virgin ground but the ground slowly revealed itself as a tailing outwash area from the pit above. The material is now so overgrown with trees and covered with a thick layer of duff (pine needles, bark, branches) that it gives the appearance of unmined ground. I got a massive boomer signal on the GPZ and I honestly thought it was a can. A quick dig with my pick revealed instead a large chunk of gold and quartz. The first sight of the nearly 9 ounce piece about stunned me but I soon determined that what I had found was mostly quartz, but still, a pretty nice find. There are around a couple ounces of gold embedded throughout the white quartz. In theory this is the largest "gold nugget" I have ever found, but obviously the fact it is mostly quartz takes a little of the shine off that. Still, absolutely no complaints from this kid on making this find! The large specimen was obviously washed through whatever sluice and riffle system the oldtimers were employing, and washed down to end up resting on top of the tailing outwash fan. At one time it was just sitting there in plain view, although it would have taken a sharp eye to have spotted the gold if a person was just walking by. Then a forest grew on the tailings and a century of pine needles and branches fell and obscured the piece. Steve at location where 8.75 ounce gold specimen was found I of course had visions of even more finds to be made in this apparently overlooked location, but very diligent hunting for quite a few hours turned up nothing but some trash and one little bit of rock with gold in it. In Australia specimens like this are usually just crushed (dollied) and the gold panned out. We have a better market for specimen gold and so this could be sold as is. Unfortunately the mass of quartz hides most of the contained gold so this is not a prime specimen. It would be better with less quartz showing more of the gold. If the quartz were pure white it also would be more valuable but it has darker mineral inclusions. Still, I have considered slicing it up to see if any good cabochon material can be obtained for jewelry purposes. I have also considered just soaking it in Whink as an experiment to see how many months it would take for very weak hydrofluoric acid to completely dissolve the quartz, leaving loose crystalline gold. For now doing nothing has been the easy option. Close up of 8.75 ounce gold specimen found by Steve Herschbach I would like to say the Minelab GPZ 7000 had something to do with my finding this specimen, but the truth is I think there is enough lumpy gold in it that nearly any decent detector would have found it. The GPZ 7000 is remarkably sensitive to specimen gold containing finely dispersed gold, but that is not a problem with this specimen. The warning for some however is that as a shallow and very loud response it is easy to assume a trash target like a can. Always be aware that there are still large gold nuggets and specimens out there at very shallow depths, and the faint "zip-zip" sound so many ears are trained to find can initially be thrown off by what seems to be a junk signal. I seriously thought I was excavating a can so that I could properly dispose of it! I get irritated by all the aluminum cans I see discarded when I am out detecting and end up packing them all out. I wish I could say the same for all the steel cans and trash I find, but that simply is not practical, though I haul out what I can. The California Mother Lode country is criss-crossed with gold-bearing quartz veins large and small. Most were too small to be developed into mines and many were small enough to be completely overlooked. Even quartz veins that for the most part are barren may have one small section that is rich in gold. What this means is that chunks of quartz like this can be found almost anywhere in Mother Lode country. Clark, William B., “Gold Districts of California;” Bulletin 193, California Division of Mines and Geology Sacramento, California, 1970 This article originated as a post on the DetectorProspector Forum. Additional details may might be found there in follow up posts. ~ Steve Herschbach Copyright © 2015 Herschbach Enterprises
  12. 5 points
    This year has not been going exactly as I imagined it would. My stated goal for the year was to set a new record for days in the field detecting. So far however, it has been anything but that. No complaint - I have been devoting myself to visiting family and other things that took precedence over prospecting. Weather has also been a bit dodgy this spring leading me to sit out things a little waiting for better conditions. What time I have had for prospecting has mainly been spent in northern Nevada. I am really taken with the desert and am very partial to the sagebrush and grassland country. It reminds me a lot of the time I spent in Australia with huge wide open spaces to wander. I enjoy the idea that gold can be found nearly anyplace, the exact opposite of Alaska, and I love just wandering from valley bottom to hill top because, well, you just never know. There is some old and interesting geology here that leaves nuggets in what might seem to be pretty unlikely locations. I did find one nice little patch that produced about half my gold this spring, but the rest were just strangely random isolated nuggets. I would find one and get all excited, then after several hours of methodically gridding the area wonder why that one nugget ended up there all alone. My largest nugget, at 3/4 oz, was just such a find. I wandered out of what looked to be the "good area" and just lucked into this nugget all by itself on a hillside far above the valley floor. Where did it come from? Why nothing else near it? I like to wander around freely but due to the nature of the gold deposits I am relying heavily on the GPZ 7000 map screen and GPS track to attack areas in chunks. I just start someplace and then use the GPS mapping screen to fill in all the pixels as completely as I am able in a given area. My goal is to completely hunt that area and then write it off forever as being hunted. Each hunt area is dumped to X-Change building my master map of hunted areas. I am approaching it much like building a jigsaw puzzle, each planned hunt taking in a segment and filling it completely. I still like to wander around a lot but the main focus is long term - the many years I have ahead of me hunting these areas. I could just do what I have always done and hunt piecemeal but I decided it is time to switch gears and get more methodical about things. I figure there is a lot of that random "scattered gold" out there and that a slower long term goal to gather it up is a major part of my plan going forward. Using GPS mapping is key to getting good coverage while eliminating the chance I might waste time hunting and rehunting the same locations over the years. The GPZ is also critical to this effort as I have great confidence in its ability to sniff out almost any gold that finds its way under the coil. Small gold, flat gold, wire gold, deep gold - the GPZ is my gold vacuum. All detectors miss gold, including the GPZ. But right now if I have to hunt an area once and once only, and have my best shot at finding what might be there, I do not know of a better option for me than the GPZ 7000. One detector, one coil, one pass over the ground ever - what are you going to use? Steve's Minelab GPZ 7000 going deep for the gold! If gold is found a person of course has the luxury of coming back with different coils and different detectors and trying to find gold missed before. The problem is finding that first nugget. If it does not get found, you just wander on, never knowing that maybe you just missed a great patch, for the lack of finding that first, most important nugget. I am convinced there are many undiscovered patches out there still. The patches with the big easy to find solid gold may be very rare now, but "weak" patches comprised of smaller, or deeper, and harder to find specimen type gold surely exist. They will be found by people hunting outside the commonly known popular areas. That is what I have been doing. Hunting locations where other prospectors are rarely if ever seen. I honestly think I have been a bit lucky as of late but the methodology is sound and it is what I will be doing for as long as I have left to swing a detector. GPZ 7000 gold fresh out of the ground I continue to follow the various posts around the world about the GPZ 7000 and people's experiences with it. Mine are pretty boring. I turn the machine on, maybe do a quick ground balance routine, and go detecting. I may not even go through the ground balance motions. I just turn it on and pick up from where I left off the previous day. I usually run in High Yield, Normal Ground, Gain of 12, Smoothing Off, Ground Tracking On. I leave most audio settings alone. The detector will often run noisy with these settings, especially in alkali locations. I may lower the threshold to 20 to knock out some excess noise, or just lower the overall volume level using my headphones. The GPZ lacks a master volume control that lowers all sounds at once, and so benefits from the use of an external booster with master volume control. The problem for me is that is one more battery operated gizmo, and so I often just use my headphones instead to gain the overall volume control I crave. I tend to run my detectors noisy but like it to be quiet/noisy not loud/noisy. 2.14 ounces of nice Nevada gold found by Steve with Minelab GPZ 7000 Beautiful 3/4 ounce gold nugget found in northern Nevada by Steve with GPZ 7000 When the ground responses get a bit much, as is the case with ground salt, I react more by slowing down and modifying my swing than changing detector settings. So far I would say about half the gold I found was pulled out of fairly high salt response ground with the attendant moaning/groaning or hee/haw responses the GPZ produces in that type of ground. That seems to be a show stopper for a lot of people but I don't pay much attention to it myself. I have this theory that killing those responses might kill my gold finding capability on this ground to a certain extent, as I know some of these locations have seen other detectors that ignored the salt. They also missed the gold. Coincidence? Maybe. I have plans for more experiments regarding this but have had a hard time tearing myself away from my limited detecting time to do more comparative tests. Later. Anyway, I have quietly picked up just over a couple ounces of gold with my GPZ 7000 so far this spring. The largest nugget is 3/4 oz and there are several other nice pieces I am very happy with. Nice solid, clean gold, my kind of stuff. An odd mix from very worn appearing to rough. I am unfortunately getting waylaid again with things I must attend to before I can go prospecting again and so I decided I may as well post this update now. It could be weeks before I get out prospecting again. Until then, here are some happy pictures to enjoy! This article started as a thread on the DetectorProspector Forum. Additional information may be found there in follow up posts. ~ Steve Herschbach Copyright © 2015 Herschbach Enterprises
  13. 4 points
    The Garrett ATX was introduced by Garrett Electronics in 2013 and is still in production. It is a pulse induction metal detector waterproof to ten feet. It is unique in that it is one of the few metal detectors retailed to the general public in a housing developed for military applications. Garrett makes a military land mine detector called the Recon Pro AML-1000. It was developed and marketed after the Garrett Infinium, the only underwater ground balancing pulse induction (GBPI) metal detector made by a major manufacturer at the time. The Recon is notable for the waterproof telescoping compact design with hidden coil cables. The new ATX is a highly refined detector combining the best of the Garrett Infinium and Garrett Recon AML-1000 into a single package. The actual housing is almost identical to that used by the AML-1000. The electronics has attributes from both detectors. It is a considerable improvement over the much older Infinium electronically and folds into a remarkably small package without disassembly. I was one of the first individuals to obtain a Garrett ATX when they came out as I had been waiting for a new waterproof ground balancing pulse induction metal detector ever since the Infinium came out over ten years ago. I honestly was a bit surprised Garrett came out with a second generation waterproof GBPI before the competition has released any at all. Ground balancing PI detectors have the ability to work in a combination of salt water and black sand/hot rock environments in unique ways. VLF and even standard non-ground balancing PI detectors suffer under these extreme conditions. The Infinium showed me what might be possible in Hawaii but it suffered from issues common in first generation detectors. There was room for improvement, and I am hoping the ATX addresses the electromagnetic interference (EMI) and salt water instability problems that plagued the Infinium. My first impressions were positive, with my first detailed report at Gold and Silver with the New Garrett ATX. I have a separate article on prospecting with the ATX at Gold Nugget Detecting with the Garrett ATX. The ATX is a versatile detector and will see use prospecting, relic hunting, jewelry detecting (above water and under) and even coin detecting. I have two beach detecting articles on the ATX - Beach Detecting in Hawaii With The ATX and Garrett ATX Return To Hawaii. Garrett ATX waterproof pulse induction (PI) metal detector with 10" x 12" coil The Garrett ATX is uniquely versatile in its physical aspects. It can be extended longer than most people need yet can collapse into a very short diver configuration due to the three piece lower rod design. Garrett ATX collapsed for diving use For storage or backpacking the ATX folds even shorter yet to only 20" in length due to the rotating/folding coil design. The ATX coils are rather unique in that they are integrated with the lower rod with the wires running through the rod and a rear mounted hinge on the coil. This allows the coil to fold back completely over the rod and/or detector body. The rod/coil assembly can be rotated 90 degrees for hunting walls and to enable a more compact stowed configuration. Garrett ATX folded for storage or backpacking All the ATX functions are accessed through a top mounted control panel with rubber topped touchpad buttons and LED indicators. A shift button allows each button to have at least two functions allowing for a full feature set in a simplified layout. Garrett ATX Control Panel Quick Guide to Garrett ATX controls from Owner's Guide - Click image for larger version The Garrett ATX comes standard with a 10" x 12" DD search coil. Optional 8" round and 15" x 20" mono coils with integrated lower rods are also available. New for 2017 are 11" x 13" enclosed coil options in both mono and DD designs. The ATX does have a built in waterproof speaker and so does not require headphones. It does come with land headphones that use a waterproof connector, the same connector that Garrett uses on the Infinium and AT Pro/AT Gold models. The same waterproof headphones available for those models work on the ATX and are required if it is desired to put the headphones underwater. The included headphones have a waterproof cable that can be submerged but the headphones themselves must be kept dry. A short adapter dongle is also available to convert the ATX waterproof headphone connector to the standard 1/4" female receptacle so standard metal detector headphones may be used. See the Garrett ATX Accessory Page for details on headphones, search coils, and other accessory items available for the Garrett ATX. There is information there on using Garrett Infinium coils on the ATX, and notes on how to chest mount or even backpack mount the ATX control box. Finally, the ATX runs off eight standard AA batteries, eliminating any shipping or airline issues that can be a problem with some PI detectors. The detector comes complete with both alkaline and NiMH rechargeable batteries plus a 110V and 12V charger system. The detector runs approximately 10-12 hours on a charge when using headphones, less if running off the speaker. The best method is to use the rechargeable batteries and carry the alkaline set as backup. Garrett ATX search coil options I have had the Garrett ATX now since the fall of 2013 and so have had a solid year with the detector. It really does take about a year for me to settle down my thoughts about a detector. I tend to be all giddy with the new toy at first, having fun, and discovering new things. The strong points and weak points are revealed with use over time, and now I think I can offer up a fair summary of the detector. The ATX is a bit difficult in that Garrett started with the premise of using an existing housing designed to military specifications, and then decided to put a detector in it for consumer retail sales. On one hand this is really great as we get this very unique detector design that would never have been developed just for consumer sales. On the other hand it means for some uses the ATX is just not a very good fit. For other uses it works pretty well. It just so happens I am an avid prospector and an avid beach hunter. I do not beach hunt as much as I like but when I do it I really go after it. Because of this the ATX hits a particular sweet spot for me personally. I really do need a good pulse induction metal detector that can be submerged in saltwater. I would keep the ATX for that purpose alone. I am very happy with its performance as a beach detector especially on beaches where there is black sand mineralization or volcanic rock to deal with. The fact it also does very well as a prospecting PI is almost a bonus for me. From a straight up prospecting perspective Garrett also scores though nobody needs a seven pound detector waterproof to 10 feet while desert prospecting. However, if all I had was a couple thousand dollars to invest in a brand new, full warranty PI for gold prospecting it would be a Garrett ATX. I believe the ATX is superior to the White's alternatives in overall performance and it is far less money than a new Minelab PI detector. I will not speak for the Australians but in the U.S. the ATX holds its own for PI performance and I feel quite comfortable using it gold prospecting. I could wish for a lighter package but the fact is it works and a person who puts in the effort should do just fine with the ATX. I know I can. The ATX does well for relic hunting applications and I have even found I can cherry pick coins halfway well with it. I have always been partial to pulse induction detectors and Garrett has won me over with the ATX. I enjoy using the detector and I can make good finds with it, and that is all I can ask of any detector. Some of Steve's finds with the Garrett ATX in the first year of use In retrospect I have actually done remarkably well with the ATX since I got it, considering it is only one of several detectors I have been using and not the one with the most hours on it. I have found about 3 ounces of gold and platinum jewelry with the Garrett ATX plus about two ounces of gold nuggets with it. I have found gold nuggets in Alaska, Arizona, California, and Nevada with the ATX under sunny skies and in pouring rain. My ATX has spent a couple weeks of days underwater in rough surf and is none the worse for wear. Many thanks and a hat's off to Garrett for producing my all time favorite Garrett detector. ~ Steve Herschbach Copyright © 2015 Herschbach Enterprises Official Garrett ATX Page Garrett ATX Instruction Manual Garrett ATX Color Brochure How To Disassemble and Clean the ATX Coil Shaft & Camlocks Garrett ATX Accessory Page Report on new 11" x 13" Search Coils Forum Threads Tagged "garrett atx" Garrett Metal Detectors Forum Garrett ATX vs Minelab GPX 5000 Garrett ATX Technical Specifications* Internet Price $2120.00 Technology Ground Balancing Pulse Induction (GBPI) Frequency 730 pps Autotune Mode(s) Slow Motion and Non-Motion Ground Rejection Four Tracking Speeds and Fixed Soil Adjust Can ground balance into salt soils Discrimination Dual Tones, Iron Check & Reverse Disc Volume Control Volume Limiter plus headphone controls Threshold Control 25 level push button setting Tone Adjust No Audio Boost No Frequency Offset Automatic Pinpoint Mode Yes Audio Output Proprietary headphone socket, Headphones supplied plus Waterproof Speaker Hip Mount No Standard Coil(s) 12" x 10" Open Spoke DD (Or Optional 11" x 13" Coils) Optional Search Coils 8" Round Mono, 20" x 15" Mono, 11" x 13" Enclosed DD, 11" x 13" Enclosed Mono Battery 8 AA rechargeable and disposables supplied Operating Time 10 - 12 hours Weight 6.9 pounds Additional Technology 13 level adjustable gain control Notes Waterproof to 10 feet (requires optional submersible headphones) *Notes on Technical Specifications - Detailed notes about the specifications listed in this chart.
  14. 4 points
    Metal detecting for gold nuggets is perhaps the most difficult type of metal detecting. That is partly because simply having an excellent gold nugget detector does little to insure success. The operator not only needs to be extremely proficient with a capable metal detector, but also needs to have general knowledge about gold prospecting and where gold is likely to be found. This short guide is intended to focus on some of the most important aspects a person should consider when starting out new in the nugget detecting game. Metal detecting for gold nuggets is the gold mining equivalent of big game hunting. Many areas produce fine gold and small flakes, but these areas will not usually prove productive with a metal detector. Only areas with larger gold nuggets will be of interest, and so many locations that are fine for panning and other types of mining will not be worth your time if you plan on going for the big nugget. Researching the area to confirm that large nuggets have been found there in the past will help make your hunt successful. While detecting may limit you to fewer sites and more time between each nugget you find, the fact is that successful detector operators tend to find gold nuggets far larger than the finds of the average recreational miner. Detecting is not nearly as physically demanding as most types of mining, and lends itself well if you enjoy roaming freely rather than working hard at a single site. Steve metal detecting for gold with White's MXT metal detector Here are a few facts and tips to get you started: Today's machines can detect gold weighing under a grain with ease. There are 480 grains per Troy ounce with nuggets under a grain quite literally being pinhead size objects. The depth of detection grows with the size of the target. A one grain nugget may be found at two inches, a match head size nugget at four inches, and a quarter ounce nugget at ten inches. Only the largest nuggets will be found at depths over a foot. Metal detectors will not normally find buried accumulations of fine gold directly. The higher the operating frequency of the detector, the more sensitive it will be to small gold, but with the penalty of also being more sensitive to iron minerals. This can result in more false signaling and difficulty of operation in highly iron mineralized areas. Lower frequency detectors are generally less sensitive to small nuggets, but handle iron ground better. Frequencies on today's nugget detectors range from a low of 3 kHz to a high of 71 kHz. Pulse induction (PI) detectors are a special type of unit that act like they are extremely low frequency detectors. PI detectors main strength is in ignoring the worst ground mineral conditions and finding large gold nuggets at maximum depths though a few models also do well on the smaller gold. Most models feature manual ground balance controls, which allow the machine to be adjusted for the general iron content of the ground. When the ground being searched is relatively homogenous, these controls require minimal adjustments and work well. When the ground being searched has wildly varying iron content or many out of place mineralized stones (referred to as "hot rocks") then these manual controls will have to constantly be adjusted to maintain proper performance. Detectors that feature automatic ground balance will require less adjustment and will have less false ground noise. The best option is to have both manual and automatic ground tuning options in one detector. Nugget detectors find all conductive metals. Most units have the ability to tune out many common iron and steel trash items. Pulse induction detectors are not so good at discriminating out trash items and should generally be considered as "dig-it-all" type detectors.. Any gold located should be treated as an indicator, since rarely will a nugget occur by itself. It is much more likely that more nuggets are nearby, and gold smaller than the detector can locate or beyond its immediate depth of detection is present. Such leads should be followed up with further excavation and sampling with gold pans or other mechanical methods, A metal detectors greatest advantage is that it needs no water, a near-universal requirement for most methods of placer sampling. Use this to your advantage to easily check material that is far from water, such as arid locations or deposits located well uphill from the stream. Large nuggets sing out with a loud signal, but since most targets will be small, train yourself using the smallest detectable nuggets your machine can find. Learn the faint but very distinct sound that small or deeply buried nuggets make. Small aluminum or lead targets can be used as an acceptable substitute for gold. Always use headphones to enhance your ability to hear these faint targets. Coil control is one of the most important aspects of proper metal detector technique. Small items may only be detected at a few inches or fractions of inches. Hovering the coil any appreciable distance over the ground is one of the most common reasons for gold nuggets being missed. The detection field projected underground resembles an inverted cone, with the deepest depth of detection in the center of the coil. At maximum depths only a tiny area is seen by the detector, and so overlapping the sweeps is important when detecting a productive area or "patch". To find gold go where gold is found! Metal detectors can be used to prospect new areas but do not expect to find much gold in areas where gold has never been found. Instead, research and frequent areas with past known production of the kind of gold you want to find. Research is a real key to success. Remember to always obtain permission to detect on mining claims or private property and be aware of any possible restrictions on public lands. Commit yourself to learning your detector. Do not make the investment if you do not plan on spending some time to properly give the method a chance. It will be time profitably spent. The one thing that sets successful detector operators apart from the crowd is their patience and persistence. They enjoy the hunt itself, and consider the day well spent even if no gold is found. Consistent success will only come with practice. I strongly believe there is no one best detector for all conditions. The best detector for each area will depend on how much ground iron is present, how large the gold is, and how much trash is in the area. Operator expertise has by far the greatest effect on success. If you purchase a second detector, having a low frequency model and a high frequency detector will give you more versatility. Identical detectors will also interfere with each other electronically and must be kept far apart, whereas differing models can work side by side. The most important accessory item you can own is a quality set of headphones. A good set will muffle outside noise, enhance the faint sounds most nuggets make, and be comfortable for hours on end. Audio quality is of extreme importance. Insist on trying several headphones with your detector before you buy. The differences can be amazing. Make sure that the headphone has its own volume controls and matches your detector for mono or stereo operation. Several ounces of gold detected at Ganes Creek, Alaska in 2010 by Steve Herschbach Other important accessories include a stout digging tool, such as a stainless steel trowel or a short handle pick. A magnet can easily pick up small steel trash items that may be found and are hard to locate exactly. A plastic scoop or cup is indispensable in helping to separate a small nugget from the soil by scooping and waving the soil over the detector search coil. Snap plastic search coil protectors over the bottom of your search coil to protect it from wear. Carry spare batteries and a plastic bottle for your finds. Check into the possibility of using a belt or chest harness with the detector control box to protect it and remove the extra weight from your arm. Do not overlook accessory search coils. Smaller search coils will be more sensitive to smaller targets while giving up some overall depth. Larger coils will produce more depth of detection on larger targets, but will lose the ability to find some smaller nuggets. Small coils are more popular and will pay off in bedrock areas in particular. They can make a detector of moderate sensitivity perform like a higher frequency detector. Large coils work well for finding oversize nuggets discarded in tailing piles. Coils are not interchangeable between models; only coils made for your machine will work with it. The chart below shows the advantages of using both smaller and larger accessory coils. Coil Size vs Depth Fisher Gold Bug 2 Source - Field Testing the Gold Bug 2 by Gordon Zahara The most important goal is to put yourself on nugget bearing ground. These areas are well documented and can be researched. Check the land ownership and contact claim owners if need be for permission to nugget hunt. If you frequent areas that have not produced coarse gold, do not be surprised at a lack of success. For information and reviews of specific metal detectors see Steve's Guide to Gold Nugget Detectors. A huge resource for questions asked past and present is this website's Metal Detecting & Gold Prospecting Forums. Be responsible! Fill your holes behind you, and remove any small trash you excavate. Proper and responsible practices will keep more areas open to us all. Do not remove gold from mining claims without permission. It is theft and may result in that claim being made off-limits to other nugget hunters. Protect our hobby so we can all continue to enjoy it in the future. Good Luck & Good Hunting! ~ Steve Herschbach Copyright © 2009 Herschbach Enterprises
  15. 3 points
    FISTS FULL OF GOLD - How You Can Find Gold In The Mountains And Deserts by Chris Ralph Yes, it’s true that you can prospect for and find your own gold – it’s still out there! The title of my book is “Fists Full of Gold” because that’s what I hope it will bring you. I’ve put in years of experience to make this book the most comprehensive prospecting book ever written. It's very different from what is on the market already – It's focus is to teach you how to find gold deposits, both placer and hard rock. There is a huge amount of information here that is just simply not available in any other prospecting book. It has plenty of basic coverage for new prospectors but lots of material for those guys who have some experience and want to learn more, plus even more advanced information for prospectors with decades of experience. It is up to date with all the latest technology and science. - Chris Ralph This book takes a unique and different approach in teaching the “trade skills” of prospecting – it covers not just equipment, but the knowledge you really need to find those locations with recoverable gold. This information is important because in the final analysis, no matter well you operate your dredge, metal detector or other prospecting equipment, unless you can find the deposits where the gold is concentrated, your equipment cannot help you recover it. It's designed to be the one prospecting book you will never outgrow. It’s a quite a reference: more than 360 pages long with over 225,000 words. That makes it longer by far than any other prospecting book written for individuals – longer than any 2 or 3 of them combined! In spite of this, it’s all written for the average individual who does not have any formal training in geology or mining. Fists Full Of Gold book by Chris Ralph A note from Steve Herschbach, professional prospector - "I was privileged to be able to help proof Chris' book and I can say without doubt it would have saved me years of learning things the hard way had it been available when I started out. This book addresses the huge gap that exists between books teaching elementary prospecting methods and hard to read technical manuals. Chris brings together a wide array of information in a readable fashion. If you are ready to take that next step up from the basics, this is THE book to read". Some of the highlights of the information contained in the book include: The basics of prospecting and finding gold, including: The fact that there is lots of gold is still out there to be found How to use a gold pan, including crevicing, mossing and sniping for gold How to get the best recovery out of your sluice box or highbanker How to use a suction dredge to find and recover paystreaks How to operate a dry washer for gold An extensive section on metal detecting, perhaps the best on the market Building your own equipment, including building your own: Portable sluice box Lightweight suction dredge Desert dry washer How to operate a small scale commercial mining operation How to deal with and get the most out of your black sands How to get the best prices for your gold, specimens and nuggets A full coverage of the geology of gold and silver mineral deposits: All about minerals and how to identify them Minerals associated with gold deposits Rocks: what they are and how to identify them Basic geology for the prospector in an understandable form A detailed explanation of placer geology and how paystreaks form A detailed explanation of hard rock geology and how gold deposits form How to recognize many types of hard rock gold and silver deposits How to do research to find your own rich concentrations of gold: Using and understanding topographic maps, aerial photos and GPS Where to find little known sources of information on gold deposits How to use geology maps to find gold Signs and indicators of gold deposits that you want to look for in the field: How to read and interpret signs of old timer workings How to recognize geologic indicators of gold mineralization How to prospect for commercial deposits of gold and silver Mining law and how to stake and maintain your own claim Platinum placers and deposits – How to prospect for them Diamonds in placers – How to recognize them Maps of where to find gold in the US and Australia Plus hundreds of photos, diagrams and illustrations to explain the concepts presented in the book. 8" x 11" 362 pages. Find It On Amazon
  16. 3 points
    This section focuses on gold prospecting for individuals and small time operators. Equipment used may include metal detectors, suction dredges, gold pans, and sluice boxes. You will find articles here to help you for both beginners and pros. There is location information, equipment reviews, and more. Steve's Mining Journal - Real life gold prospecting and metal detecting stories spanning over 40 years. Gold Prospecting & Metal Detecting Guides - Basic information to get you started. Recreational Mining Sites, Parks, Museums, etc. - Locations available to the public to look for gold and other rocks & minerals. State Specific Information - General gold locations, geology, and history. Mining Claims For Sale in Alaska - Mining claims and leases in Alaska that are being offered for sale. Gold Prospecting & Metal Detecting Library - Online books and other reference material about gold prospecting and metal detecting. Steve's Guide to Gold Nugget Detectors - updated now for over 20 years, Steve gives honest opinions regarding various metal detectors past and present. Steve's Reviews - Equipment reviews focused on metal detectors for gold prospecting, much more in depth than the previous summary. Detector Prospector Forums - Forums on metal detecting for gold, gold panning, rocks & minerals, gold dredging, geology, plus coin, relic, jewelry, and meteorite detecting. Links To Other Websites - Links to other websites and forums with relevant information. Metal Detector Database - Metal detector feature and specifications database with user reviews.
  17. 3 points
    Our first trip of 2004 to Moore Creek got a lot accomplished, but the big jobs remained ahead. I was contacted by my friend George, better known on the internet forums as seeker. He has a background with heavy equipment and offered to help out with the generator and bulldozer. George is a very accomplished and well traveled detectorist and this trip would give him a chance to try out his brand new Minelab GP 3000. And so we scheduled a another trip up to the mine. Our first attempt was aborted at Rainy Pass due to bad weather. It was some of the poorest flying conditions I have experienced in some time. We sat and drank coffee in Skwentna hoping for the weather to lift, but it never did. This is one of the frustrations of flying in Alaska that one faces from time to time. There is nothing much to be done about it but try again in the future. But the false starts are disappointing and you never get back the lost time. Yet another trip was scheduled for a couple weeks later, and this time we made it. My brother Tom was able to break away from work for this short weekend trip, and so it was my father, George, Tom, and I. This time the weather was better and so we made it into the mine with no problem. Then came the usual task of hauling our gear to camp and opening the place up. Every time we leave we have to try and “bear-proof” the place by covering all the doors and windows with steel. Every time we return we have to open everything back up. I want to make some heavy-duty hinged steel doors for covers to speed this process up. For now it is lots of work with hammer and nails. George took a look at the generator and after a bit of work with the fuel system got it going. The previous owners had rigged it to auto feed with a fuel pump out of a barrel. George hooked the original fuel tank back up and bled the fuel system and it finally fired up. We now had electricity to add to our propane stove and propane refrigerator/freezer amenities. Suddenly Moore Creek was starting to feel civilized; the microwave even worked! Aerial view of Alaska Range on way from Anchorage to Moore Creek Arrival days are always short days. We decided to look for a little gold. I gave Tom my Minelab GP 3000 and I tried the White’s MXT I had brought along just to see how it worked in the hot rocks. George had his new GP 3000 and my father his Tesoro Lobo. It was a bit of fun at the end of the day, but only Tom came up with gold, a nice 0.55 oz specimen. Tom has always had a knack for detecting although he has done relatively little detecting over the years. It must run in the family. The next day we got more serious. George wanted to try and start the old D9-18A bulldozer that we have sitting in camp. This unit had been sitting next to the trail going from the airstrip to the cabins during all those early years when we had made visits to Moore Creek. It apparently was abandoned as dead but in the last couple years the previous owner had finally got it running. A piston was replaced and they got a little trail work done before the unit started shaking badly again. They thought it might have a bent crankshaft, which would be bad news. Still, it was running when it was parked, so we figured we might as well try and get it started to see how bad it was. The fact that it is parked in camp makes it easier to work on than the one located over four miles by trail out of camp. These old bulldozers have a small gasoline engine referred to as a “pony motor” that acts as a starter for the main diesel engine. The first thing to be done is to get the pony motor running. They use a six volt battery instead of a twelve volt to run their own little electric starter motor. We hooked up a battery with a charge and determined the starter worked. We then checked for fuel… and there was none to the carburetor. It turned out the fuel line from the little gas tank to the pony motor was plugged up with rust particles. The line was so well plugged it was hard to believe they had used the pony motor to start the dozer. Nothing all that hard to fix but time consuming taking all the lines apart, cleaning them out, and reassembling everything, especially since many of the fittings were stripped or otherwise in poor condition. D9-18A bulldozer in camp The throttle controls were disconnected from the pony motor, so George sat up top and ran the starter while I worked the choke and throttle manually. The pony motor started and I immediately wished I had hearing protection on. That little motor was loud. It also became immediately apparent we had a coolant leak in the head. But it did not look too bad for a short try, and so George kicked in the clutch and turned over the big diesel. It cranked and my brother shot some starter fluid in the air intakes while I kept working the pony motor throttle. The big motor turned and we got some smoke puffing. It looked ready to start. So we backed off. We wanted to let the pony motor cool down as the short effort had it pretty hot. We also looked the big motor over and checked for coolant and found none. Off to the creek with buckets we went. We dumped the water into the system, and it promptly ran right back out of the bottom of the radiator. Well, we looked but the radiator is fairly well enclosed. We think there is a drain open or hose pulled. We sure hope so, and that the radiator is not cracked. I have to believe they drained it before walking away. We were tired of fighting with the unit, and decided a set of manuals would be very helpful at this point. The dozer seemed like we could start it, but I had no desire to hurt things more by running the unit without better information about the recommended oils, coolants, etc. We decided to round up manuals before making another try at starting the dozer so we could run the unit through a full pre-start checklist. And find out where that drain is. My father and I figured to start trail work up to the other bulldozer outside of camp and it was decided that George and Tom should go hunt for gold. It was hard to say when Tom would get a chance to visit again, and George had already done well in getting the generator going and a start on the dozer in camp. Dad and I figured we would go off and do some work and let them have a little fun. Prospecting can actually be pretty tough work, but looking for gold always beats working on equipment or clearing trails since you just might find gold. There is an old bulldozer trail up to the unit that the operators were following when they got the dozer stuck about three miles from camp. It is about 4.25 miles by trail to the dozer along the trail itself. It starts out in the woodlands at camp, rises above tree line into that nasty alder and willow zone one runs into in Alaska, and then up onto the clear areas above. The small mountains around Moore Creek rise a couple thousand feet above camp, to total elevations of around 3000 feet for the tallest. Once you get above the alders it is very open terrain and very easy travel whether by foot or ATV. Old dozer trail in wooded area above Moore Creek camp The old dozer trail was in pretty good shape but alders had grown into some lower stretches and willows choked off some upper stretches. These two plants are like giant weeds in Alaska, and the alders in particular grow at amazing rates in the long daylight hours. They are the bane of the Alaska hiker due to their propensity to grow outward horizontally from a slope before curving upward. Along trails they curve in from both sides and crisscross in the middle. You don’t hike through alders; you climb over and under them, and so they really slow travel. It is impossible to drive an ATV through them, and they rapidly grow into and shut trails off to ATV access unless a trail is constantly maintained. One secret of locating old trails in Alaska is to look where the alders are thickest. They love disturbed ground, and old trails and ditches are easily spotted by looking for lines of alders and willows on hillsides. My father and I headed up the trail with chainsaws. He walked on up ahead and I followed with the Honda 200 three-wheeler. He was pretty much just scouting ahead, while I followed up at a slower rate, making sure the trail was clear enough to easily get through on the three-wheeler. With the dozer over four miles away by trail and over a couple 2000 foot hills, we wanted to be able to drive there with fresh batteries, tools, oil, etc. We could have just bushwhacked on up and got to work, but it would be a case where something would be needed, and then you would be looking at a long hike to camp and back. The trail needed to be cleared for ATV access to the dozer. This proved to be a very wise decision. My father disappeared up the trail while I worked along. I would park the ATV, then clear on up ahead with the chainsaw. Then set the saw down, walk back tossing brush aside, and get the ATV to drive it up to the chainsaw. There was lots of back and forth but I was making pretty good time. There were long stretches that needed no clearing, and so after slowly getting though a thicket a sudden advance would be made for some distance. I was bringing the three-wheeler forward at one point, when the unit made a loud squeak and stopped like the brakes were on. A long period of rolling back and forth and cutting logs to get the rear off the ground and I determined a rear axle bearing was seizing up. I decided to hike down and get George to seek advice as I had no tools on me anyway sufficient to tackle an axle. I was about a mile out of camp but it was all downhill and therefore a short hike. I found George by the ponds above the cabins with his new Minelab GP 3000 metal detector. I told him what had happened. Then I finally asked him if he was having any luck. He said he thought so and dropped a heavy rock in my hand. I could tell by the heft this was more than one of our regular gold/quartz specimens. Amazingly, George has not washed it off yet. Gold was glinting thought the yellow mud caked on the nugget. I headed over to the pond and washed it off. I think I was almost more excited than George. It was a fantastic gold nugget about the size of a golf ball! Not just any nugget, but one with small fingers of gold creating a delicate pattern over the entire surface of the nugget. George's amazing museum quality gold nugget from Moore Creek Moore Creek has lots of smaller nuggets that are predominately just gold, but the gold here is very close to the original source. Even the smallest gold is not worn or rounded, but just as it appeared as the rock that enclosed it rotted away. This also means that much of the gold has quartz attached, and the larger multi-ounce pieces have generally been about half gold and half quartz. I had come to expect this, and was surprised and very happy to see such a large relatively solid chunk of gold come from Moore Creek. The fact that George found one means that more are out there to be found in the future, and that made me very excited indeed. We went back to the cabin, and the nugget weighed in at 3.74 ounces. This surprised George somewhat as it was heavier than he thought and so he was thrilled. Not a bad find for his very first nugget with his new Minelab GP 3000 and his first at Moore Creek! Bottom view of George's Nugget Another very good sign for the mine is that the nugget was found in virgin soil on the edge of what we suspect is a large chunk of virgin ground. The fact is that I and others had missed the nugget by the smallest of margins. We had all hunted the area getting just smaller gold. I’m sure I’d been within a couple feet of the nugget, and it was only a few inches down. Anyone could have found it, but George was the first to get right over it. In any case, that virgin area is looking pretty good right now. I figured George would be hot to go look for more gold after a find like that. But on hearing the problem with the three-wheeler he put his detector aside and we hiked up to the Honda. After a brief consultation we decided I should just get on it and ride it back to camp. It needed more work then we wanted to tackle there in the woods. So I got on and went. It squeaked, and would seize up but I would roll it backward to free it up and go on again. Then it seemed like it decided to work again and I cruised into camp without pause. We drained the oil out of the motor and got the Honda turned upside down. We got it apart enough to determine there was really not much we could do without a new rear axle assembly. One wheel had actually been welded onto the axle and the rest was in poor shape. We drilled a hole in the bearing carrier and pumped it full of grease. Then got it back together and I drove it around camp a bit. It seemed better, but it was obvious we had not repaired it. The bearing could totally give out at any time. Honda 200 ATV with trailer at old cabin in Moore camp Tom finally showed up and he had quite a pile of gold to show. He actually had not been doing very well, but got into a hot spot and found several specimens in a fairly small area. He had 0.19, 0.43, 0.53, 1.06, and 1.78 ounce pieces and so was feeling pretty good about it, but his eyes about popped when he saw George’s nugget. George was playing it all kinds of humble and stuff but we assured him we’d trade twice the normal type of gold finds at Moore for a fantastic museum quality piece like he had found. It is truly a find to be proud of. It was late and we all were tired so we cooked up some food and waited. It was starting to get darker, which tells you how late it was, and still no sign of dear old Dad. I learned a long time ago not to worry about Bud Herschbach in the wilds of Alaska, but still as it got even darker I started to wonder at what point we should go out looking. But then he finally showed up, and just as well as it was getting dark enough to be hard walking. My father can out-hike most people half his age, and had decided to go all the way up to the stuck bulldozer to check it out. He reported that a half mile up the trail from where I had stopped there was a very thick patch of willows where he lost the trail. He calmly described literally crawling through these willows and having “something very large” jump up a few feet in front of him and make a huge amount of noise moving off in the brush, but he never did figure out if it was a bear or a moose the brush was so thick. It was probably a moose. He is telling this and I’m thinking I would have had a heart attack right about that time but he refused to make much of it. He has run into a lot of animals in the woods in his years as one of Alaska’s pioneer surveyors. He finally made it up to the bulldozer and reported it looked in a lot better shape then he had expected and certainly better than the one in camp. It was buried to the top of the track on one side and to about half a track on the other side. On his return trip he found looking downhill that he had gone through far more willows then need be, and had picked out what he thought was the shortest route possible through the thicket and marked it with flagging on both ends. There was one day left to go on our three day weekend trip. After a good night of sleep Dad and I hiked up to do more trail work. We decided to save the Honda for now for the critical task of hauling heavy loads to and from the airport, like the big empty bottles of propane we planned on backhauling out this trip. I had decided to go on a hunt for more three-wheelers to fly into the mine. Honda three-wheelers are still pretty common in Alaska and can be had for very little money. Most importantly, we can fly them in easily in the Cessna 206. Being dependent on a single three-wheeler that could break down any moment did not seem like a good idea. I wanted some redundancy and more spare parts. We could also use more ATVs for the upcoming bulldozer project to make it easier to get multiple people with loads up to the site. This trip wound down with little excitement to report. We got the trail cleared all the way up to where the willow thicket started, and once through that it would be clear sailing. My father and I had had enough clearing for the day and so we figured we’d leave that last small but tough stretch for later. Tom and George had prospected most of the day, but the luck had run thin and only Tom had found a 0.35 ounce piece. Funny how quick you get spoiled finding gold that I now say things like that. Not long ago a third ounce nugget would have really seemed like a big nugget. Just over 8 ounce gold nuggets and gold specimens found at Moore Creek, Alaska Overall the nugget detecting was quite productive. Tom and George did most of the detecting and found over 8 ounces of specimens between them. George's 3.74 ounce nugget is his largest ever, and Tom's 1.78 ounce piece surpassed his previous largest of 1.64 ounce, found at Moore Creek on his last visit. While this nugget detecting is fun it serves a very serious purpose at Moore Creek. First, 50% of detected nuggets go to the LLC to help fund operations. Or, as in George's case, the finder has the option of purchasing back the LLC percentage which achieves the same goal. More importantly, every nugget find is plotted on maps. As of this trip almost 70 specimens and nuggets have been located totaling over 50 ounces of finds. The map is revealing certain "hot" areas on the creek. Certain zones are producing more nuggets than others. Some tailing piles have produced multiple finds, some none at all, and some just a single piece. Any finds at all increase the probability of a particular pile containing more gold from mere speculation to almost total certainty. Some areas that look very good have turned out to be not so good and vice versa. At Moore Creek it can truly be said that metal detectors are a vital part of our initial exploration program. Our short but really productive trip wrapped up and we flew back to town. Our generator is running, old dozer puffing, trail nearly cleared to the stuck dozer, and more. But this particular trip will always be remembered as the one when George found that beautiful 3.74 ounce gold nugget. It truly is a find of a lifetime and the nicest at Moore Creek so far. ~ Steve Herschbach Copyright © 2004 Herschbach Enterprises
  18. 3 points
    The Minelab GPX 4500 detector was released in the spring of 2008 and is currently still in production. The Minelab series of pulse induction (PI) metal detectors starting with the SD 2000 are widely acknowledged as being some of the most powerful gold nugget prospecting detectors currently available. The GPX 5000 is the latest and most refined in the series but the GPX 4500 is only just a step behind it in features and performance. See Steve's Guide to Differences of Minelab SD, GP, & GPX for details. The GPX 4500 created a page in gold rush history by being singled out as the detector of choice in Africa for some time. Many large nugget finds were made there with the new GPX 4500 and starting around 2009 demand far exceeded supply as African prospectors were willing to pay any price to get what they believed was the only detector capable of possibly making them rich. Buyers in the U.S. drove prices far over retail due to extreme demand and these units were resold in Africa for prices well exceeding $10,000 per machine. This amazing demand was almost single-handedly responsible for driving Minelab sales and stock prices to all time highs. When the GPX 4800 and GPX 5000 were introduced Minelab stopped selling the GPX 4500 in the U.S. and Australia but demand was such that it continued to be sold in Africa. Finally, in 2015 the GPX 4500 was reintroduced for sale again in those countries as an entry level pulse induction model (for Minelab) priced at less than half what the GPX 5000 sells for. This makes the GPX 4500 an exceptional value at this time. Minelab GPX 4500 Pulse Induction (PI) metal detector for gold prospecting and more I got my own GPX 4500 in 2008 and saw many others in use at my old mine at Moore Creek, Alaska. The GPX 4500 made the ground light up like it had never been hunted with many nuggets found in already detected locations. Here is my report at the time about what I observed at Moore Creek: "I have run a little pay-to-mine operation at Moore Creek for four years now. We have old tailing piles that have nuggets in them. Some piles produced quite a few nuggets, and so everyone and their brother has been over them hoping for just one more. For instance, Dean's Hill. Dean found a 6.54 oz nugget a mile below camp on a pile. Rich Lampright found I think about 6 more ounces of smaller specimens on the same pile. Anyway, well over a pound came off this one pile. Now, these piles are small hills. You might be talking 300 feet long by 100 feet wide by 40 feet tall. Big but not something a person can't cover every square inch of. There have been probably 50 people hunt Dean's Hill using everything from the SD2200 on up to the GP3500 and probably a GPX-4000 or two last summer. There are other hills with similar reputations, including Bud's Island right near camp. Over 100 people have hunted it since it is so near camp. So the guys show up this year with the GPX-4500. A determination was made almost immediately that all ground should be treated as virgin again, and sure enough nuggets started coming out of Dean's Hill and Bud's Island and other places that were well and truly "hunted out". It was simply way too many nuggets to chalk up to anything other than the GPX-4500 being able to hear nuggets previous units could not hear at Moore Creek. ads by Amazon... I attribute this to two things. Previous SD/GP units had a tendency to sound very faintly on hot rocks at Moore Creek. So you got to where you usually ignored those sounds as they were almost always rocks and listened for something just enough different to indicate a real target. It is possible with the GPX to completely and absolutely tune out those faint hot rocks, allowing whisper faint nuggets to be detected. They might not actually be deeper per se, it is just that you could not discern them before. Same difference as far as I'm concerned. Plus, with the Gain and extra timings you can crank the GPX up for some insane performance. Steve F got his biggy by running the GPX up to the point where the ground was super noisy. You'd not normally hunt that way but he was focused on one spot, and it did allow him to get an exceptionally deep target. The bottom line is I am absolutely convinced the GPX is doing stuff that could not be done before. It was too many people getting too many nuggets out of too many hard hit spots to be anything else. There is no doubt in my mind that money spent on a GPX-4500 is money well spent. Remember, though, it can't make the gold. We had a couple GPX users who simply could not seem to get over nuggets. Anyway, hopefully Rob and Glenn and Steve and other Moore Creek visitors will chime in here with some of the settings they were using at Moore Creek to help little old me out. I am headed back up to Moore Creek August 8th to prep ground for next season but plan on firing my new GPX up for the first time finally. I gave away everything I found in June so it would be nice to have at least one nugget to call my own this summer!! Any tips would be most welcome. Steve Herschbach Moore Creek Mining LLC July 25, 2008" Gold found with Minelab GPX 4500 at Moore Creek, Alaska in 2008 - largest nugget 3.5 ounces The was a period of time after the GPX 4500 was discontinued in the United States that the GPX 4800 and GPX 5000 were the only two PI models available from Minelab. Garrett introduced their new Garrett ATX at less than half the price of those detectors. It was a bargain at $2120 compared to almost $6000 for the GPX 5000. I do not know this for a fact but I believe that Garrett had something to do with the GPX 4500 being reintroduced for sale. The GPX 4500 at $2699 with two coils was close enough to the $2120 ATX with one coil, that it pretty much stopped the ATX dead in its tracks as a prospecting detector. Up until that point I had been recommending the Garrett ATX as a bang-for-the-buck alternative to the much higher priced GPX uits. Given the extra power and versatility of the GPX 4500 at the new lower price, and the GPX 4500 is now my recommendation for anyone wanting a "bang-for-the-buck" new full warranty high power PI for gold prospecting and possibly even beach or relic detecting. Official Minelab GPX 4500 Page Minelab GPX 4500 Instruction Manual Minelab GPX 4500 Product Brochure Minelab GPX 4000-5000 Timings Charts Difference Between Minelab SD, GP, and GPX Models Forum Threads Tagged "minelab gpx" Minelab Metal Detectors Forum Minelab GPX 4500 Technical Specifications* Internet Price $2699.00 Technology Ground Balancing Pulse Induction (GBPI) Frequency 1100-4500 PPS? Autotune (Motion) Mode(s) Very Slow, Slow, Medium and Fast Ground Rejection Slow, Medium, Fast Tracking, Fixed, and Off Soil Adjust Six settings (timings) - see chart below Discrimination Variable 1-10 and Off in Menu Volume Control Variable 1-20 in Menu Threshold Control One turn control Tone Adjust Variable 1-100 in Menu Audio Boost Quiet, Normal, Deep, Boost in Menu Frequency Offset Automatic Tune plus Manual 0-255 in Menu Pinpoint Mode No Audio Output 1/4" headphone socket (No speaker) Headphones supplied Hip Mount Shaft Mount Only Standard Coil 11" round DD and 11" round Mono Optional Search Coils Over 100 accessory coils available Battery Rechargeable 7.4VDC 9.2A/hr Lithium Ion Operating Time 14 - 15 hours Weight 5.3 lbs (w/11" coil, excluding battery (1.7 lbs) Additional Technology Multi Period Sensing (MPS) Dual Voltage Technology (DVT) Smart Electronic Timing Alignment (SETA) Numerous Audio Adjustments via menu Coil (Double D/Mono/Cancel) - 3 pos. switch Notes The GPX 4500 employs an external battery carried on a backpack harness and connected to the control box via a power cord. The detector is normally suspended from the harness with a bungee cord, allowing for nearly weightless operation in level ground. *Notes on Technical Specifications - Detailed notes about the specifications listed in this chart.
  19. 3 points
    The White's V3i was introduced in 2009 and is still in production. The V3i was originally released as the White's Spectra Vision or simply White's Vision. Due to a name conflict with another company the name was changed to White's Spectra V3. The original Vision and V3 models both suffered from software issues. Updates were issued and finally consolidated into the final White's Spectra V3i model which is still being manufactured today. All previous models can be updated to the latest V3i software by returning the detector to White's Electronics. Details here. This all leads to quite a bit of model confusion when buying used versions of these detector because it is not always clear if a model has been updated or not. The V3i was also later released in a feature limited model called the VX3. There are several things that make the White's V3i unique. One of the most obvious is the use of a very bright high contrast color screen, still ahead of its time compared to anything else on the market. The V3i takes screen customization to a level that quite frankly is unlikely to be exceeded in the near future if ever. There is a reason for that that I will explain shortly. The V3i was also one of the first metal detectors to incorporate a proprietary wireless headphone system designed to overcome the lag issues common in aftermarket solutions at the time. It was initially promised that the wireless system would also enable communication via a plug in dongle that would allow the V3i to be programmed via software on a PC. This ended up being one of the never realized disappointments of the White's V3i. The headphone system ended up working well enough after initial problems were ironed out but the proprietary nature of the system limits the choice of headphones to a single model. White's V3i multifrequency metal detector The V3i is the direct successor to the White's DFX, a dual frequency metal detector that could run at 3 kHz and 15 kHz, either separately or both at once. The V3i took this another step, by running at 2.5 kHz, 7.5 kHz, or 22.5 kHz, again either separately or all three at once. This is very unique on the market today. Most multifrequency detectors either let you selectively choose a single frequency to run at from several choices, or they run several frequencies at once. The V3i is unique in letting you do it either way. The V3i comes with a 10" round DD coil. One of the design goals was that is was to be able to use the coils already in existence for the White's DFX and MXT models, the so-called Eclipse series. The V3i did achieve this goal, but the ability to use a transmit boost function was generally limited to newer versions of those coils that are "V" rated. Coils that are not V rated may overload when transmit boost is employed. This is honestly a bit of a non-issue as there is little reason to ever employ transmit boost but it does seem to worry a lot of people that non-V rated coils might not be performing up to specs. White's coils are individually serial numbered, with the serial number stamped into on mounting ear of the coil. Serial numbers that start with "V" indicate the coil is V rated. Aftermarket coils would be especially suspect in this regard. For more information on Spectra coils some excellent information has been compiled here. D2 10" Round DD coil, 6" x 10" DD coil, and 4" x 6" DD "Shooter" coil The 10" round DD coil that comes with the V3i is a decent coil. The 6" x 10" Eclipse DD coil however is possibly the best all around prospecting coil for the V3i. The solid construction is less likely to hand up on stubble and the narrow profile is good for getting into tight locations. The 4" x 6" Shooter DD coil is great for trashy locations and small gold nuggets. The large 12" concentric coil and even the 9.5" concentric coil do not handle extreme ground mineralization very well, and the 12" is too large for many other tasks, like coin detecting trashy locations. One aftermarket coil is worth mentioning, because it is one of the only reasons I own a White's V3i. A company called Applied Creativity made some coils marketed by famed White's dealer Jimmy Sierra. One of these coils was a 3" x 18" model with a special "figure 8" winding called the Bigfoot. This coil was actually made for the DFX and is an exceptionally light weight coil yet capable over covering large areas quickly and efficiently. The Bigfoot does not get a lot of depth, but for recovering shallower targets like recent coin drops and jewelry it is unmatched in performance. Unfortunately this coil is no longer made and used ones easily go for several hundred dollars if you are lucky enough to find one. Several types were made and not all will work on the V3i, only those made for the the MXT and DFX are compatible. Original White's Spectra Vision model from 2009 with Bigfoot Coil Compatible being a relative thing. The Bigfoot is not V rated and some will not work properly on the V3i. Almost any of them will exhibit highly skewed target id numbers in the 22.5 kHz range, but oddly enough this can be used to good effect for some jewelry detecting. The bottom line is I had a Big Foot for my DFX and kept it for use on my V3i. The Big Foot / V3i combo is my number one dry land jewelry detector. White's V3i - My Third Try. The White's V3i does have a 22.5 kHz Prospecting Mode and other features that in theory make it a proficient prospecting detector. The machine is hot on small gold in the 22.5 kHz mode. When the original Vision came out I did some bench tests on it versus the MXT sing a 0.7 grain test nugget (480 grains per Troy ounce). An MXT with a 4" x 6" Shooter coil at max Gain would barely signal on the nugget within 1/4" of the coil. The same Shooter coil was used on the Vision in Prospecting Mode (22.5 kHz only), with no tweaks except max RX Gain. The threshold a bit ratty but no worse than MXT at max Gain. The Vision got a good hit at 2" and whisper at 3". I then engaged the TX (transmit) Boost, raising voltage to the coil from 10V to 30V. I then got a good hit at 3" and whisper at 4". That is a 50% increase on a tiny nugget by engaging TX Boost. This is easily better than MXT performance and actually closer to what I'd expect from a GMT. This was an air test and ground conditions are unlikely to allow running at full gain with TX Boost engaged but it would work in milder ground. In fact Transmit Boost will work against you in bad ground and it also cuts battery life dramatically. Still, this test shows there can be benefits on small gold items in particular. Of interest also is that the test was done with an old coil from my MXT, proving that not all coils need to be V rated to work properly. 0.7 Grain (480 grains per Troy Oz) Gold Test Nugget There have been some good gold nugget finds made with the V3i in the mild ground at Ganes Creek, Alaska. My friend Marko used the V3i there for at least two visits and reported to me that he thought the V3i was unexcelled at identifying deep ferrous junk versus gold nuggets in the relatively mild ground at Ganes Creek. He had quite a few ounces of gold to prove it! He used the stock Prospecting mode exclusively. The bottom line is that the V3i is first and foremost a detector designed for coin and jewelry detecting, and I would not recommend it specifically for somebody looking for a gold nugget prospecting detector. Other machines like White's own GMT or MXT can be had for half as much money that are far more practical as nugget detectors. However, if you do own a White's V3i, rest assured it can be used to find gold nuggets. It would in particular be useful in milder ground with copious amounts of ferrous trash where its advanced discrimination capabilities can be put to good use. In more mineralized ground the V3i the V3i may struggle however because it's ground balancing system is not up to tracking in bad ground and manual adjustments can be difficult to make due to the way the ground balance system is controlled. The tracking must be "locked" and the only manual adjustment that can be made from that point forward are small offsets to the locked setting. Don't worry about this for regular metal detecting - I am specifically talking about gold prospecting in highly mineralized ground. If the V3i has a weak spot this is it. ads by Amazon... I said earlier in this article that the V3i takes customization to a level unlikely to be exceeded now or in the future. The V3i is very much metal detector engineers dream detector, with direct access to many machine functions that are hidden in other detectors. This in theory allows the user to create almost any detector they want with the right degree of programming. What has been revealed in actual use however is that the number of functions and their interactions create layers of complexity that overwhelm most people. The V3i can be operated quite well with its factory preset programs and a bit of tweaking, but at the end of the day it represents feature overkill. It is a great detector for people who love to fiddle with the detector itself, but for most metal detecting the average users prefer something simpler that just gets the job done. The VX3 was a response to this by offering similar functionality in a more feature limited way. I think the V3i will be a high water mark when it comes to this type of feature overload and it is unlikely anyone will in the future try to outdo it, for the simple reason doing so is not the sure way to sales success. For me personally the V3i is one of the most capable jewelry detectors ever made, especially when coupled with the Bigfoot coil. The ability to customize both the screen and audio responses combined with expanded target VDI ranges on jewelry type targets at higher frequency ranges makes the White's V3i a jewelry hunters dream machine. That said, similar results can be had by people with simpler and less expensive detectors. The V3i is just a machine for the true detector nerd, and I have to say I guess that is what I am! Official White's V3i Page White's V3i Instruction Manual White's V3i Advanced User Guide White's V3i Information Page White's V3i & VX3 Master Reset Selectable Frequency And Multiple Frequency Forum Threads Tagged "whites v3i" White's Metal Detector Forum White's Spectra V3i Technical Specifications* Internet Price V3i $1349.00 w/Wireless Phones $1555.00 Technology Induction Balance (IB) Frequency 2.5, 7.5, & 22.5 kHz, together or separately Autotune Mode(s) Varied Motion Settings Ground Rejection Tracking, Fixed & Manual Soil Adjust Beach Mode Discrimination Visual, Tone, Notch - Ultimate Customization Volume Control Yes Threshold Control Yes Tone Adjust Yes Audio Boost Yes Frequency Offset Yes Pinpoint Mode Yes Audio Output 1/4" headphone socket & speaker Hip Mount Shaft Mount Only Standard Coil(s) 10" Round DD Optional Search Coils Over 15 accessory coils available Battery Eight AA Operating Time 8 - 10 hours Weight 4.5 pounds Additional Technology Wireless headphones, exceptional color screen, ultimate in programmability Notes A machine for true "detector nerds"! *Notes on Technical Specifications - Detailed notes about the specifications listed in this chart. V3i example screens - click image for larger version
  20. 3 points
    Benchtesting Rocks & Minerals with an F75 Metal Detector Introduction From the earliest time when we were aware of our surroundings, most of us looked for pretty rocks. We wondered what interesting or valuable minerals might possibly comprise them. Now as adult hobbyists, I doubt if any of us hasn’t benchtested an interesting rock from curiosity, and wondered what actually produced the signal. Although a sensitive benchtest usually has little in common with how marginally conductive rocks and minerals respond to metal detectors in the field due to ground effects, we can learn and become familiar with how rocks and minerals in our respective areas respond to metal detectors in a benchtest. A sensitive metal detector’s electromagnetic field penetrates rocks, usually generating either a positive or a negative signal in response to whatever material is in the rock. We can sometimes determine whether such signals should be investigated further, or whether worthless iron minerals produced them. I’d generally describe my benchtest results as worthwhile and informative, but that notwithstanding, I look forward to doing a benchtest because I think it is an intriguing study on its own merit. That said, how do you conduct a benchtest? I’ll describe my methods and hopefully we’ll see what you think about it. Benchtest Requirements and Techniques Benchtesting ideally requires a visually displayed, fully calibrated, manually adjustable ground balance that covers the entire (soil) mineral range from salt to ferrite. As a minimum, the detector should feature a threshold-based true motion all-metal mode, and preferably an additional true non-motion all-metal mode for significantly improved sensitivity to borderline samples. Visual displays in either of the true all-metal modes are essential for target ID, Fe3O4 magnetic susceptibility and GB readouts. I prefer a small (concentric) coil to promote detector stability and improve sensitivity to the rock sample, to ensure uniform sample exposure to the coil, and to minimize EMI (electromagnetic interference) especially if benchtesting at home. Elevate the sensitivity control as high as possible while maintaining reasonable detector stability such that you can clearly hear changes to the threshold. To check for a target ID, move the sample back and forth across the coil at a distance that produces the best signal but does not overload the coil. To determine ground balance and Fe3O4 readouts, advance the sample toward the coil, back and forth to within an inch or two (depending on sample size and signal strength) of the coil’s electrical sweetspot. Ensure your hand does not come within detection range of the coil to avoid creating false signals. If you extend your fingers to hold the sample, this is not an issue when testing larger samples. If necessary use a plastic or wood food holder that can firmly grasp small samples. Benchtests should be conducted utilizing a minimum of two widely diverse GB control adjustments. Initially I prefer the same GB control adjustment that is typically required to keep my detector ground-balanced to the substrates in my prospecting areas. It’s a personal preference that works for me. That particular GB control point (F75 / GB86) is more likely to improve any rock or mineral sample’s signal strength compared to using a more reduced (more conductive) GB compensation point. The next step is to use a dramatically reduced GB control adjustment (F75 / GB45) as suggested by Fisher Research Engineering. This setting ensures that (obviously weathered) oxidized samples do not generate a positive signal from any type of non-conductive iron mineral inclusions, particularly maghemite mineralization that may be present within such rocks. It follows that this second benchtest will, if anything, slightly subtract from the sample signal strength, particularly with low grade and otherwise marginally conductive samples, compared to the first step of the benchtest at GB86. As a general rule, I do not recommend the F75 / GB45 compensation point for benchtesting (non-oxidized) mafic samples that are dominated by constituents such as common magnetite or other black minerals that normally support highly (non-conductive) elevated GB readouts. Such samples can produce strong negative threshold responses at the reduced GB compensation point. It will be difficult or impossible for the signal from a marginally conductive substance to successfully compete with those negative threshold signals. For non-oxidized samples Fisher Research Engineering suggests using F75 / GB65 rather than the F75 / GB45 compensation point, since obvious iron mineral oxidation should visually be absent from such samples. With the above discussion in mind, extremely fine-grained, unweathered magnetite that occurs in pyroclastic material (for example volcanic ash) can drop into the GB45 range, but it is extremely rare. Unweathered volcanics do frequently drop into the GB70's due to submicron magnetite, but the recommended F75 / GB65 compensation point will eliminate those positive signals. The arsenopyrite sample depicted above is a good example of a commonplace mineral that we encounter in the silverfields of northeastern Ontario. Generally field examples could be described as marginally conductive and many are low-grade. A good many react with only a mild positive signal, and sometimes not at all to a benchtest depending on which GB compensation point is used. The high-grade, solidly structured sample above produces a strong positive signal in either zero discrimination or true motion all-metal mode with the ground balance control adjusted to the GB compensation point required for our moderately high mineralized soils. As noted, that’s approximately F75 / GB86, although in the field, of course, it varies somewhat depending on location and coil type / size employed. The response is not as strong as a similar size and shape metalliferous sample would produce, but it does generate a surprisingly strong benchtest signal that would be readily detectable in the field. Even with the GB control dramatically reduced to more conductive values (F75 / GB45), to ensure that any positive signals produced by non-conductive iron mineral inclusions should now only produce a negative threshold signal, it is no surprise that this (non-oxidized) specimen continues to generate a strong signal. For those readers unfamiliar with detector responses to such minerals, the same general response scenario described above with arsenopyrite applies to other marginally conductive minerals such as galena, pyrrhotite and to a lesser extent even iron pyrites. Ordinary iron pyrites is generally innocuous, but maghemitized pyrite, pyrrhotite, and the copper sulfide ores, particularly bornite and chalcocite, can be a real nuisance in the field due to magnetic susceptibility, magnetic viscosity, and / or electrical conductivity, just depending on what minerals are involved. Such variable responses from arsenopyrite and many other mineral and metalliferous examples clearly infer that signal strength and potential target ID depends on a sample’s physical and chemical characteristics, including the quantity of material within a given rock. These factors include structure, size, shape, purity (overall grade), and magnetic susceptible strength of iron mineral inclusions. Moreover, the VLF detector’s sensitivity, the GB compensation points employed, the coil type and size, and the sample profile presented to the coil further influence benchtest target signal strength and / or potential target ID readouts. Incidentally, neither of my PI units will respond to the arsenopyrite sample depicted above, even with a TDI Pro equipped with a small round 5” mono coil, the GB control turned off, and a 10 usec pulse delay to deliver its most sensitive detection capability. That result is typical of most, but certainly not all sulfides and arsenides that occur in my areas. Higher grade and solidly structured pyrrhotite, an unwelcome nuisance iron sulfide, and collectible niccolite, a nickel arsenide, are commonplace mineral occurrences here that do respond strongly to PI units, although their respective VLF target ID ranges are quite different. As a related but slight diversion, the photo below depicts a handsome example of the widely occurring mineral sphalerite. It forms in both sedimentary beds, and in low temperature ore veins. It is interesting to collectors because it possesses a dodecahedral cleavage which means that it breaks smoothly in twelve directions, and it is usually triboluminescent, meaning that it gives off a flash of light when struck sharply. Like many desirable minerals lurking in prospecting country, unfortunately sphalerite doesn’t react to metal detectors. A Final Word The foregoing is intended to illustrate that sensitive metal detectors can be utilized as a supplementary tool to assist with evaluating rocks and minerals. There is no question that the benchtest has serious limitations, particularly if trying to distinguish positive signals produced by some types of iron mineral inclusions from weak conductive signals. That notwithstanding, a positive signal that persists below the F75 / GB45 compensation point cannot be confused with iron mineral negative threshold signals produced at that same compensation point. Therefore a positive signal merits further investigation. Such signals are almost certain to be generated by a marginally conductive mineral or a metalliferous substance. On the more interpretive side of a benchtest, we need to point out that weak positive signals from lower-grade samples of minerals such as arsenopyrite, galena, pyrrhotite, chalcopyrite, and doubtless a few others, may disappear well before the GB control is reduced to the F75 / GB45 compensation point. We learn early that benchtests are frequently equivocal and require interpretation based on any further evidence that might support the benchtest result. Look for iron oxidation in addition to structural or other physical evidence as described above that could explain why a sample reacts as it does to a metal detector. Jim. This article was promoted to an article from a forum thread. Additional information may be found there in follow up posts.
  21. 3 points
    The gold pan is the basic miner's tool. They are used for prospecting and testing of deposits for heavy minerals. The final cleanup of most sluicing and dredging operations is done with a gold pan. For some, gold panning is a mining method in itself. To find gold, a beginner needs nothing more than a gold pan and some basic tools. While many associate steel pans with gold mining, steel pans today are mostly sold to the arts and crafts market and as souvenirs. Plastic pans are molded with riffles that aid panning and are colored to help show the gold. Green is considered the best color as it not only shows gold well but also the blacks sands that one is attempting to separate from the gold. Some pans feature a recessed bottom referred to as a "drop center". This creates a catch trap around the bottom of the pan to hold the gold. Some panners prefer this design while others feel it also holds undesired material so both styles are popular. Plastic pans can be molded with "cheater riffles" that make it easier to pan and still not lose the gold. A 14" gold pan is about the right size for most adults, while most children would probably be better served with a 10" gold pan. The ''standard'' steel gold pan of old was 16'' wide at the top, 10'' wide at the bottom, and 2.5'' deep. When full, and level with the top (a ''struck pan''), it would hold about 336 cubic inches, or 0.0072 cubic yard. In theory, this means that 140 pans equal a yard of material. In reality, packed gravels ''swell'' when removed from the ground. A swell of 20 to 25 percent is average. It can therefore take from 150 to 200 pans to process a yard of material. The figure used most often is 180 pans per yard. Assuming about ten pans per hour, a good panner should be able to pan about a half-yard a day. A very proficient panner working easy material may be able to pan up to a yard a day. Needless to say this would be back-breaking work! In good hands, the pan is one of the most efficient gold recovery devices available. In fact, panning samples that show substantial amounts of extremely fine float gold has misled many a miner. This is gold so small that although it can be recovered with a gold pan, it will wash out of most simple sluice boxes and gold dredges. Anyone wishing to mine for gold needs to become proficient with a gold pan. It is an invaluable tool for testing, and for the cleanup of larger scale equipment, such as sluice boxes. There is some skill involved in gold panning, however, and the big mistake most people make is in not learning how to pan before going out for the first time. Gold pans old and new - classic 16" steel pan (rusted) and square riffled plastic LeTrap pan Find a tub large enough to move the pan around inside the tub. Obtain a few flakes of gold, or lacking gold, use small flattened lead shot. The gold or lead flakes should be about 1/16" in diameter or smaller. Fill the tub with water, and fill the pan level to about 1" short of the top with sand, gravel, and small rocks. Some actual stream gravels are best. Carefully count out a number of lead or gold pieces and push them into the material in the pan. This is the key thing about this process. It is necessary to start with a known number of pieces in order to gauge how well the panning process is going. Ten flakes is a good number to use. There are lots of ways to pan, but all that is important is getting rid of that sand and gravel while keeping those sample pieces. Submerge the pan just below the surface of the water, and allow the water to soak into the material. It may be necessary to stir the material up somewhat to wet all the material in to pan. Pick out any larger rocks at this time. Then shake the pan vigorously side to side and front to rear, all the while keeping it just under the water and basically level. The goal is to get all the material in the pan moving vigorously and very soupy. The gold or lead is much heavier than an equal size piece of sand, and so with all the material moving around the test samples will quickly sink to the bottom of the pan. The next step involves taking the pan of material and tilting it forward, away from the panner, and scooping some water up out of the tub. The goal is to try and make a wave similar to that seen on a beach. Scoop the pan into the water and then lift the pan while tossing the water away. The water should ride up the tilted pan, and then as the water flows back out of the pan it will carry some material out with it. Getting comfortable while panning can be challenging! The secret is in keeping the material in the bottom of the pan stationary and letting the water wash off the top layer in the pan. Do not dump the material out of the pan; wash it out of the pan. Three or four of these washing actions take place. Then the pan goes back to the level/submerged position for another round of vigorous shaking. Then back up, tilt forward, and scoop/wash the material. And that is it, over and over, until only a few spoonfuls of material remain in the pan. Watch the material carefully while washing for a glint of gold or lead. If a piece is seen, stop and shake it back down into the bottom of the pan. If the pieces are seen often, it means the shaking action has not been vigorous enough to sink the samples to the bottom of the pan. More care must be used when washing as the last bit of material remains in the pan. One wrong scoop and everything in the pan will go in the tub! When only a spoonful of material remains, swirling the material around in the bottom of the pan with a small amount of water will reveal the pieces of gold (or lead). A very handy tool at this point is the snuffer bottle. The snuffer bottle is a plastic squeeze bottle with a tube inserted into in such a fashion that small items can be sucked into the bottle but cannot escape. This makes it easy to spot your samples, and then suck them up while getting as little sand as possible. When all the pieces have been captured, dump material still in the pan into the tub. Then take the cap off the snuffer bottle and dump out the captured pieces back into the pan. It should now be very easy to separate the test samples from the tiny amount of sand remaining. Now count them! All the original test pieces should be captured. If not, rinse everything out of the tub into the pan and start all over. The first goal is to get to where the test pieces are reliably recovered every time. When that point is reached, the next goal is to try and pan faster, to speed up the process. Beginning panners take incredible amounts of time on a single pan when they are learning, sometimes 15-20 minutes or more. But with practice it should take no more than a few minutes to work a pan of material. Gold panning championships are measured in seconds, not minutes. If this kind of practice does not take place before going out to do some actual gold panning, the chances for any kind of success are very minimal. The new prospector will have no idea if there was gold in the material they have chosen to pan. When nothing is found, they will have no idea if it is because of poor panning technique or just because there was no gold to start with. It is very important to have confidence so that when a particular spot is sampled with a pan a few times and nothing is found, the decision is then made to try panning somewhere else. Video - Basic Panning Equipment & Panning Techniques One item that can really help the panning process is a screen. Screens are used to remove rocks from material before panning, aiding considerably in the panning process. Screens are designed to fit into or over the pan. Choose a screen size that will eliminate most material while not being so small that gold will not pass through the screen. A screen with a 1/2" hole size is safe for most locations. If all you anticipate is small gold, a 1/4" hole size will eliminate more worthless material quickly. Consider carefully before using a screen any smaller than 1/4". It is good practice to thoroughly wash material through the screen with vigorous shaking, then to quickly flip the screen over and dump it out where you can take a quick look at the discarded material, in case a large nugget has been accidently screened out. The last thing you want to do is toss the screened material out into deep water, and see what you think is a large nugget flying out with the rocks! Other items handy for gold panning are rubber gloves for protection from cold water, rubber boots, a small shovel or large scoop, a small pry bar and of course a snuffer bottle. And a bottle to put the gold in. Do not use glass, as it can be too easily dropped and broken. Next is the question of where to go gold panning. Always attempt to go where gold has already been found, as stumbling on an unknown gold deposit is not likely to happen. Be sure that the area is open to the public, or that permission is obtained from whoever has jurisdiction over the property. For most visitors with limited time it will be best to stick with known public sites. For a list of panning sites in Alaska visit ourPublic Mining Sites page. When panning, it usually will make more sense to spend extra time and effort filling the pan with quality material. For example, splitting bedrock crevices and cleaning them thoroughly can take some time, but the material produced will usually have a better chance of producing a good showing of gold than simply filling the pan with a couple shovels full of bank material. Panning can produce substantial amounts of gold, but the material must be chosen carefully for good results. Good Luck and Good Panning! ~ Steve Herschbach Copyright © 2009 Herschbach Enterprises
  22. 2 points
    After returning from Moore Creek in July I put the word out that I was looking for Honda 200 three-wheelers. I was offered one in good condition and bought it, plus another one not running that I purchased for parts. My father came up with a Honda 110 that a friend gave him. Our little fleet was growing. I wanted to make sure that for our assault on the old bulldozer we had plenty of ability to transport people and tools the three miles over the mountain to where the unit was stuck in a bog. When we acquired Moore Creek some of the equipment we got was actually over the mountain at another creek named Deadwood Creek. In fact, that other location was where the bulldozer was coming from when it got stuck three miles out from our camp. There was another Honda 200 ATV over at that far camp, and so my father and I decided to fly up to Moore Creek, drop off one of our just purchased Hondas, and then fly over the hill and get that three-wheeler. This proved to be a true Alaska Bush pilot adventure. I’ve flown around Alaska with my father for 40 years now and we have seen some pretty exciting moments in that time. But in recent years usually the flying is uneventful and even downright boring. Every once in awhile though you tackle some new airstrip in a remote location and things can get very interesting, to say the least. This proved to be one of those times. We crammed a Honda 200 3-wheeler into the Cessna 206 and flew it into Moore Creek. No big deal there. My father had checked out the Deadwood Creek airstrip previously when we had a friend up to Moore Creek with a Super Cub. He figured he could put the 206 in and so we went for it. The strip is dozed over the curve of a hill and grown up with brush. It is always something to be making a landing for the first time on a strip like that, and this was no exception. We hit the ground going uphill, and then had to skid to the left to stay on what appeared to be the best route. You roll up over the crest and down the other side, so forward visibility is limited. We made it but it was one of the more exciting landings I've made with him in some time. Airstrip at Deadwood Creek, Alaska over the hill from Moore Creek We explored a bit, and then loaded up the Honda 200 three-wheeler to take over to Moore Creek. The unit appeared to have real low hours but had been sitting in the weather for years. Two tires were flat, and although it would turn over the fuel tank was full of rust and it would not start. Then came the fun part... takeoff. A Cessna 206 with two guys and gear is iffy on this strip. We ran flagging over the hill so we would know which way to go since we could not see over the crest of the hill. Not only does the strip run over the hill but it is not straight. We had to spend an hour breaking brush and even tall grass as it slows you down plowing through it. We rolled the plane on down to the lower end of the strip, which meant a takeoff run up a pretty good slope, leveling at the top, then hopefully getting off the ground as we rolled down the other side. We had a preference for one direction as there are ridges to clear both ways, but the one way the ridge is farther away. Plus, if we had to abort the crash zone was smoother that way. We would run into downhill sloping brush as opposed to falling into a small valley the other way. No, I'm not kidding, you plan your crash... just in case. Only problem was a tacking tailwind going that way. So we parked and waited a half hour watching a piece of flagging tied in a tree. It finally hung down straight indicating a lull in the breeze, and we went for it. After all the suspense, we got off with no problem. That, my friends, is what it is like flying small planes in Bush strips in Alaska. This scenario may sound insane to some but it is what you have to do to be able to see and operate in the vast 99% of Alaska that nobody else ever sees. You have to be willing to land on beaches and ridges and marginal airstrips just barely carved out of the wilderness. The secret to success is an old Alaska Bush pilot saying - “There are old pilots and bold pilots but no old bold pilots”. You have to know when to go for it, and when to just give it up and go back home. And dear old Dad has proven he knows how and when to make those calls. The stage was set for the next attempt to get the old bulldozer back into camp. However, before I would return to Moore Creek I planned on making one last nugget hunt at Ganes Creek. This trip was prompted by Steve Burris finding an incredible 33.85 oz nugget at Ganes in June 2004, right on top of the ground in an area heavily hunted by others in the past, including myself. It was the largest nugget found at Ganes with a detector up until that point, and highlighted just how easy it is to miss nuggets when dealing with an area the size of Ganes Creek. Seeing a picture of the nugget gave me a case of gold fever, and the desire to give Ganes just one more try. I put the word out I was planning a trip to Ganes Creek, and in short order a group of people signed up to go the same week. Half were local people I know, and the other half were visitors from down south, mostly from Arizona and Nevada. Some of these I knew by reputation and the internet to be knowledgeable nugget hunters and so it had the makings of an interesting week. I planned on meeting my father in McGrath as the group left Ganes Creek and going straight over to Moore Creek rather than returning to Anchorage. The stuck D9 bulldozer The Ganes Creek trip is a long story in itself, but one I’ll leave for another time. The short story is that we had delays getting both into Ganes Creek and out due to the smoke from the many forest fires in Alaska that summer. It also became apparent that the years and number of hunters at Ganes Creek have had an effect on the chances of finding nuggets at Ganes Creek. I actually was very pleased with the nuggets I found, but the fact is that most of the visitors from the Lower 48 had pretty poor luck finding gold. In the early days most anyone swinging a detector at Ganes Creek could find a nugget, but at this point I think only the very experienced or very lucky will be finding nuggets in the future at Ganes Creek. It also was obvious that nugget detecting experience elsewhere does not prepare people for nugget hunting tailing piles in Alaska. It is a different game, and requires a different set of skills. Some of the guys from down south were not too happy with their finds… or lack thereof… for the week. While I found some nice nuggets and had a good week at Ganes Creek, it was with a certain amount of relief that I found myself watching the rest of the group get on the plane in McGrath and head back to civilization. I count among some of the very best times of my life those times when I have been totally on my own in remote locations of Alaska. There is something enlivening about being totally dependent on ones self and the knowledge that there is nobody to bail you out if something goes wrong. So now what? The smoke from the forest fires prevented my father from making it over the Alaska Range to McGrath to pick me up for the trip to Moore Creek. It was morning still, and I faced the prospect of checking into a hotel and waiting it out. By the time I got supper and breakfast I’d be looking at a $100 bill. The smoke was thick in the area but had lifted since early morning, and it looked flyable to me. So I wandered over to Magnuson Air and asked Lucky if he thought he could get me to Moore Creek. It costs $250 one way to the mine from McGrath but I figured I’d be getting a $100 discount by not staying in McGrath. Plus, I’d be able to get to work at the mine instead of just killing time. Lucky figured we could make it to Moore Creek, and so I loaded my gear up into the Magnuson 206 and we headed for the mine. It was actually a nice, sunny day despite the smoke, and the smoke thinned as we got to Moore Creek. We landed at the mine, and then Lucky took off to head back to McGrath. I opened up the camp and did odds and ends work waiting for my father and cousin Bob to arrive. I hung around camp a bit the next morning half expecting them to show up, and was just getting ready to go up and clear trail when they did finally arrive. They had a tale of wandering mountain passes in thick smoke trying to find a way over the Alaska Range that sounded not a bit fun, so I was glad they had made it to the mine safe and sound. We cleared the last bit of trail to the top of the mountain and so were finally able to drive our three-wheelers all the way to the bulldozer. The trail is actually an existing bulldozer route that has grown up over the years and so along some portions is actually like an old road in the lower elevations but fades to a bare trail above tree line. Once you get above tree line the ridges are rounded and smooth and so it is pretty easy to get around on an ATV. Using Honda 3-wheelers to run supplies over hill to stuck D9 bulldozer We took a dual approach to getting the bulldozer unstuck. A combination of trying to dig it out and trying to get the old beast started up. The D9 is a 1950’s era model that uses a small gasoline motor referred to as a “pony motor” for a starter. So first step was to try and get the pony motor started. It uses a 6V car type battery and so we used the ATVs to haul up a battery plus some fresh gas. The first thing we discovered was that the small exhaust pipe sticking straight up out of the top of the dozer had not been covered, and when we cranked the pony motor over water puked up out of the exhaust pipe! We drained what we could, and then ran the battery dead trying to clear water out of the system. The battery did not last any time at all, actually. The old starter motor seemed to just suck it dead in very little time. We spent the rest of the day digging away at the lower rear track where it was sunk in the mud. If we could get the motor running, we could hopefully use the rear ripper hydraulics to push down and lift the rear of the dozer up, so that logs could be stuffed under the tracks. But since we had more people than we really needed digging seemed to be another approach to take while also keeping busy. The old bulldozer has a cable lift blade in front, which unfortunately cannot be used to do the same thing up front. It can only lift, not push down. We headed back to camp eventually and put the battery on a charger overnight. Dad and Bob decided to fly over to one of the nearby mines to borrow a jack and returned with a loaned 40 ton jack. Then back up to the dozer for more digging and work. We got the rear corner of the dozer dug out far enough to get the jack under it and this started an effort of putting rocks and timbers under the jack and driving them down into the muck until a solid base was created. It took a lot of work to finally get the rear of the dozer to lift a couple inches. And with that accomplished, we stuck timbers under the rear of the track, which when the jack was let down just sunk into the muck. Over and over we jacked the unit up, stuffed timbers and rocks under the track, and let it down to all sink right back to where we started. We got the pony motor clear of water but it still would not start before the battery ran dead. And finally after a couple days we ran out of time and had to return to Anchorage. Lots of digging, lots of work with hydraulic jacks and log sections This time I returned with my other partner John, along with more batteries as the single battery was not giving us any life before it ran dead, and having to return to camp to charge it overnight was taking too much time. Plus a new jack. I found there was no spark on the pony motor, and so I pulled off the magneto, cleaned up the points, and put it back together. And Pow, Pop, Pop, Pow! Smoke came out and more water came from somewhere and got the plugs wet but at least we had fire! But we ran the batteries dead without the motor actually starting. We spent more time digging, and more time pulling every part of the pony motor apart we could trying to get it to start. It would pop and backfire and do everything but actually run. Finally we gave up and once again we had to return to Anchorage, frustrated by our inability to get the motor running. The dozer was now so dug out that it would most likely drive out of the hole, if only we could get it running. The fall colors were out in full, and winter was coming fast. We needed to do something soon or winter would put things off for another season. I got a hold of my old friend Tom, who has worked with heavy equipment for many years. He is a very busy person, but he agreed to come up and try and figure out what was up with the pony motor. I was stymied at this point, and was worried about the delay. Overland permits for bulldozer travel off claim blocks can generally only be had in the winter months. The ground is softer in the warmer months and so travel when the ground is frozen protects the ground. If we could not get the dozer running before winter set in, we would most likely lose an entire season. The main limitation in the permits is the requirement that the ground have snow cover. We needed to get the bulldozer onto the claims while the ground was still frozen. Tom, my father, and I returned to the mine for one last try in early October. The snow could fly at any moment, and we not only wanted to try and get the bulldozer running, but also wanted to stake some more mining claims. We had our hands full, and this was likely to be the last chance with the bulldozer for the season. We made it to the mine, and settled in for the evening. And awoke the next morning to snow and thick fog. It was only a dusting of snow, but it covered the ground just enough to hide the trail to the bulldozer. Add in the heavy fog, and we were soon basically lost up on top of the mountain trying to find our way to the bulldozer. Luckily I had used my GPS on the previous visit to trace the trail. Even so, what the GPS said argued heavily with what our eyes were seeing. Were it not for the GPS I have doubts we would ever have found the bulldozer that day. Winter is coming - fresh snow at Moore camp But find it we did, and Tom proceeded to try and figure out why the pony motor would not start. We had over time eliminated almost every possibility, and when you get right down to it these old motors really are not very complicated. You need fuel, compression, and spark. The only thing that seemed weird was all the backfiring and that the carb would want to blow out backwards instead of pulling air. There simply seemed to be no options left, when I thought back on my previous work on the motor. Early on I had pulled the magneto apart to clean the points. Did I maybe not put it back together correctly? It is a simple thing to disassemble, but if you are not careful you can put it back together 180 degrees out of where it came apart. I wondered about this for awhile, and finally piped up with “you know, maybe I put the magneto back together backwards”. So we pulled the magneto off, rotated it 180 degrees, and put it back together. Tom got on the dozer, turned the pony motor over… and it fired right up! I felt a very strange combination of embarrassment at having been the cause of a lot of extra work, and happiness at having finally figured out what the problem was. Tom let the pony motor run a bit, and after a rough start it smoothed out and sounded just great, albeit loud as heck. Kind of like listening to a shotgun firing 3600 times per minute. Then he engaged the clutch to the main motor, and smoke puffed out the big stack. And puffed, and puffed, and then all the sudden our bulldozer was running! Smoke coming out of the stack - the D9 starts!! What an incredible moment! The main engine really sounded good, and Tom let it warm up for some time. Then he gave a pull on a lever, and the blade lifted. We have a ripper unit on the back of the dozer, and had filled the tank with fresh hydraulic fluid. Tom pulled another lever, and the ripper blade lifted up. Dad and I got all the remaining timbers we had and laid out a parking pad just ahead of the dozer on level ground. We had just enough logs to cover two track lengths. Then the moment of truth arrived, Tom pulled more levers and the bulldozer drove out of the hole. Whoops and yells and handshakes all around ensued. Tom parked the bulldozer on our logs, and powered her down. We drained and covered everything to the best of our ability for the winter ahead, and left the dozer for the next spring. It was amazing how everything finally happened in so short a period of time, but it was all the hours of preparatory work that made it all seem so easy at the end. Dozer up and out of the hole, ready to drive to Moore Creek next spring We did our claim staking, and closed up the camp for winter. The year 2004 at Moore Creek came to an end, and the snows of winter came shortly after we left the mine. Success could not have come any later that year. Events slowed, but I did get an Overland Permit lined up in anticipation of moving the bulldozer into camp in the spring of 2005. Travel within a claim block is covered under our mining permits, but since the bulldozer was off the claims we needed a permit to bring it into camp. The main limitation was that overland movement had to be while the ground was frozen and covered with snow, and so we were aiming for an early spring operation. We were planning for April, but the winter of 2004-2005 proved to be one of the heaviest snow years on record. Dad and I flew up to the mine in April, but the dozer had snow drifted over the seat. It was still too early, and so we took advantage of the snow, and asked our friend Mike to fly a load of gear up to the dozer with his Super Cub, which was on skies for the winter. He landed on the hill by the dozer, and left a battery, propane tanks, a heater, and tarps plus some miscellaneous gear. Dad and I planned on flying into Moore Creek just before the snow melted, and so getting that gear to the dozer would have meant lots of snowshoeing. Now we were set. We monitored the snow situation, and finally flew up in early May in my brother-in-laws Citabria. Our original permit expired the end of April but I was able to get a two week extension due to the extreme snow conditions. There was still a few feet of snow on the ground in places but in most areas there was less than a couple feet. We made some passes over the bulldozer, and I launched sleeping bags and some basic camping supplies out of the plane. I’ve done some of these “bombing runs” before and they are actually kind of fun. Dad does all the work, however. I just hold stuff out the door until he yells “Go”! and I let go of it. With any luck it lands halfway close to the target. Aerial view from Citabria of snow in the hills in early 2005 We landed at Moore Creek, and hiked up to the dozer on snowshoes. We planned on camping the night, and heating the motor overnight, but it was rather warm (relatively speaking) when we got to the dozer so we went ahead and tried to start her. And amazingly, it fired right up! I had been studying my D9 bulldozer manuals, but the fact is I have never driven anything even close to one of these monsters. I really had no true idea what I was doing, but just followed the manuals. That worked well enough in getting the unit started, but finally after warming her up I had to make the big move. We loaded up all the tools, batteries and other gear. I held my breath, put it in gear, and engaged the clutch. The next thing I knew I was driving a D9 bulldozer up a mountainside. I had been warned that no matter how big these things seem, driving into too deep of snow conditions could get you high-centered in short order. The snow was only a foot or two deep, but I could not tell really how deep it was, except for my what seemed like endless trips over the trail on the three-wheelers the previous fall. I just kept her going slow and forged ahead, and after a bit it actually seemed pretty easy. Dad and I both had grins on our faces as well drove along, with all the overnight gear we had pre-staged loaded on the bulldozer unused. Up the hill I went, and down the other side. Basically just a drive over the hill, and I got to being lulled into how easy it all was. Finally we were on our claims, and camp was only minutes away. I was on cruise control, just enjoying the ride. And then the dozer broke through the crust and muck started churning! Only a heartbeat seemed to pass, but next thing I knew we had come to a stop in the middle of the trail. Apparently the low flat bog areas which we were passing through just before arriving at camp had thawed under the snow. The only good news was that it was still frozen a short distance below, but the dozer was spinning on the frozen muck and could gain no traction to get up and out of the hole we were in. Still, we had made it 99% of the way into camp, and so could not feel all that bad about the situation. It was only a 10-15 minute hike to camp, and we got a good nights sleep. Then up and back to the dozer the next morning, to get out of our little situation. We took chains, cables, and clamps for camp with us, and a chainsaw. We cleared a bunch of alders ahead of the dozer and laid them down in front of it to make an exit pad. The we cut a big dead spruce and levered it over in front of the tracks with a long pry bar. We took cables and ran then through the tracks and around the log. I fired up the dozer, and when I engaged the clutch the front end climbed up on the log and what seemed an incredible angle. I half closed my eyes, and the front end came up out of the hole, and fell over out and onto the alder pile ahead of the log. We were unstuck and on the first try. Project a year in the making - D9 finally back at Moore Creek and Steve clearing airstrip I now was much more cautious heading into camp, as my inattention the day before had got us stuck. If it even threatened to get soft ahead, I drove over the alders next to the trail, which created a natural pad. The next thing I knew I was driving the bulldozer into camp, and when I finally parked it and got off it was one of the happiest days of my life. I literally wanted to kiss the ground! Dad and I hugged and shook hands and slapped each other on the back. In all our years I do not think we have tackled a project that took so long and so much effort as moving this D9 bulldozer into Moore Creek camp. And like all things difficult to achieve, the final success was all that much more satisfying. In all the excitement I forget to take any pictures, but here is a shot of the old girl back in camp later in the year, with me working on clearing and extending the runway. I have to finish this tale by thanking Bob, John, Tom, Doug, Mike, and most of all my father, Bud Herschbach, for all their hard work and contributions towards getting our bulldozer back to camp. There is no way I could have done it without them. Thanks guys! ~ Steve Herschbach Copyright © 2005 Herschbach Enterprises
  23. 2 points
    The XP Metal Detectors company of France has been making waves with its new metal detector, the XP DEUS. So much has already been written about the XP DEUS that this page is going to focus on the Version 4 (or later) software releases starting in 2017. This new versions of the software combined with new hardware has made the DEUS into a totally different detector. For that reason this website will be referring to XP DEUS V4 or V5 specifically as opposed to earlier versions of the detector. July 2018 - Deus Version 5 Software announced and new X35 search coils announced. September 2018 - New XP ORX announced. January 2019 - 2019 Deus Model Comparison I purchased a new XP DEUS in 2014 to evaluate it as a gold prospecting detector. The DEUS was originally designed for coin and relic hunting in Europe but quickly found a following in the United States also. As a prospector I was not much interested in the detector, until the version 3.0 software update added a program specifically for prospecting, the Goldfield program. According to Andy Sabisch at Findmall the program was originally developed as a dedicated prospecting detector for the African market. It worked and was subsequently added to the 3.0 software update for the DEUS. According to XP "The GOLD FIELD program uses a different detection strategy designed to handle highly mineralized ground containing targets such as gold nuggets. In these ground conditions, small, low-conductive targets are often seen as ground noise or iron, especially when they are deeply buried. To go deeper in these difficult conditions, the GOLD FIELD program uses a true All Metal mode allowing you to accept a whole zone of ground that is usually rejected (Full Range). Rather than rejecting all the ground values below the setting (as on conventional detectors), this new program rejects only the current value of the ground which you have to adjust exactly." The short story is I found the XP DEUS and its new Goldfield program to be perfectly adequate for gold prospecting, but that was about it. The innovative wireless design notwithstanding, there just seemed to me to be nothing particularly compelling about the DEUS for gold prospecting. It is the kind of machine that if a person owned it anyway, then they would have a capable gold prospecting detector in addition to all its other uses. Given the price however to buy it specifically for gold prospecting just did not make much sense to me when detectors costing half as much did every bit as well or better. Further, a well respected person on my forum reported that he also ran into issues with the DEUS in its current form when it comes to gold prospecting. You can find my detailed review and his report both at Using The XP DEUS For Gold Prospecting at the DetectorProspector Forum. I went ahead and sold my new DEUS at that time. Fast forward to the fall of 2015. Early information about the upcoming version 4.0 software release immediately caught my interest. New coils were announced that has serious implications for gold prospectors. The new elliptical coils are 12cm x 24cm or approximately 4.7" x 9.5" which is very close to the standard established for VLF gold prospecting detectors. There is also be a new round 9" coil. More importantly, the new coils via the V4 software will enable operation much higher operating frequencies. The 9" round coil will operate at 14 kHz, 30 kHz, or 59 kHz and the elliptical coil at 14 kHz, 30 kHz, and an amazing 81 kHz!. This would put the XP DEUS V4 squarely in the realm of high frequency gold prospecting detectors. Currently the Fisher Gold Bug 2 at 71 kHz has the highest operating frequency of the popular prospecting detectors. XP DEUS V4 with new 4.7" x 9.5" DD Coil These extremely sensitive coils operate on a wide range of 21 frequencies, ranging from 13 to 81 kHz depending on coil choice. The search coils three base frequencies are 14 kHz - 30 kHz and 59 kHz for the 22.5cm (9”) Round DD coil. The elliptical DD coil has a slightly different base frequency set of 14 kHz - 30 kHz and 81 kHz. Each coil has a further 7 higher or lower sub frequencies to choose from, allowing a much wider adjustment range (Previous Deus has 3 sub frequencies). The lower frequencies are intended for general use, they provide good sensitivity to a wide range of targets, the higher frequencies will take the Deus to another level. You will instantly notice the enhanced sensitivity and the ability to find small targets that have previously been difficult or impossible to locate when searching mineralized ground with competing devices. Apart from the ability to detect through mineralized soil, the HF coils will enhance the signature from weak - low conductive targets or even highly conductive targets, that due to their shape or construction (thin or wired) are beyond the reach of conventional detectors, for example: open rings such as earrings or fine bracelets, wire framed artifacts, gold nuggets, intricate fibula’s, small coins, thin coins, etc. The new HF coils only weigh 350g and are equipped with the latest higher capacity lithium battery (850mA). The new battery is situated in the lower stem; this is a bonus especially if you are working in a remote area far from a power source as optional replacement batteries will be available. Battery life: 20 hours at 15 kHz, 27 hours at 30 khz and 28 hours at 59 & 81 kHz. New for 2018 - Deus X35 coils running at 3.7 kHz to 27.7 kHz In my opinion the version 4.0 software upgrade combined with this new coil meant the DEUS was worth another look as a gold prospecting detector. The smaller footprint of the elliptical coil will "see" less ground and better separate small gold nuggets from difficult ground conditions. The boost in frequency will also make the detector hotter on small nuggets. I therefore obtained another new XP DEUS and waited - over a year - for the new V4 update and new coils to appear. I finally went out and found my first gold nuggets with the new DEUS elliptical high frequency coil in 2017. I want to emphasize that I am a newbie on the XP Deus. Although I purchased an 11" Deus V3.2 model almost two years ago, it was with the express purpose of being able to test the V4 update with the new high frequency coil options for gold prospecting. I decided I was better off just starting fresh with version 4.0 before really digging in and learning the detector. I do get the hang of detectors quickly but this does show what can be done by somebody who went out barely knowing the machine. The other catch is that I picked a location that favors the Deus with relatively mild soil for a gold location, so mild I could run the machine full out to get the maximum possible sensitivity with the machine. These results are not going to be as easy to obtain in extreme mineral ground. You have to start someplace however and being new to the machine I wanted to give myself someplace easy to start. Finally, the goal here was to find the smallest gold I could so for the purposes of this report - smaller is better. These nuggets were recovered over the course of a day. Ten nuggets, 4.7 grains total weight. There are 480 grains per Troy ounce and with an average weight of less than half a grain I think you can agree this is some pretty small stuff. The smallest bits are probably near 1/10th grain or 1/4800th of a Troy ounce. Click picture for larger version. Gold nuggets found by Steve Herschbach with new XP DEUS HF elliptical coil The new HF elliptical coil running at 74 kHz is clearly in the same league as the 71 kHz Fisher Gold Bug 2, 45 kHz Minelab Gold Monster, 56 kHz Makro Gold Racer, and 48 kHz White's GMT. However, the devil is in the details and it will be some time before I sort out how the machines compare under more difficult and varied conditions. Again, I am not an expert with the Deus and so the settings I mention are not to be taken as "the best" or anything like that. I was actually gold prospecting so the primary focus was to find gold, not to test every possible combination of settings on the Deus. With 10 program options and numerous settings that will be a longer term project. I obviously wanted to try the Gold Field program 10. After a little experimenting I settled on the GM Power program 2 as an alternate disc mode to try. Getting from program 10 to program 2 is only a couple button pushes, so I bounced back and forth between the two programs and tweaked settings higher as I found targets and could compare readings. Gold Field is a threshold based all metal mode with what I find to be a rather pleasant digitized buzz. That's me of course, others may differ on that point. I was able to run sensitivity full out at 99. All my work was done at 74 khz, the default highest frequency setting without trying to push it higher via the offset. I figure the coil is tuned at 74 khz and so stuck with that for now. Manual ground balance about 84. GM Power I got sensitivity to 94 with only minor falsing. I reduced reactivity (similar to SAT for you nugget hunters) to 0 from the default of 2 and ran the audio response (audio boost) up to 7 (max). Both modes exhibit just a little touch sensitivity at these high gain levels. This might be tamed with the ground notch but I have not fooled with that yet and it did not bother me at all anyway. ads by Amazon... What I found was Gold Field has a softer response in general but that my boosted version of GM Power banged hard on the little bits. Not unlike going from all metal mode on the Gold Bug 2 to the Iron Disc mode. Instead of faint threshold variations you get a strong "beep". The difference is that the Gold Bug 2 Iron Disc mode has an obvious loss in sensitivity. The Deus by comparison in this particular situation actually seemed to work better in GM Power mode, but that is mainly the boosted audio at work. I left the disc settings at the defaults for GM Power which worked well - low tone iron, higher tones non-ferrous. I ran the IAR (iron reject) in Gold Field at 2. This was just enough to cause ferrous to break up. Higher settings would blank most ferrous completely but getting to aggressive can also eliminate weak gold signals. The ferrous discrimination worked very well in both programs. GM Power in particular was pretty awesome in the nail pits with iron tones firing off like a machine gun. I bumped reactivity back to 2 in the dense trash. Anyway, this is a very preliminary report and so no point getting too deep into it as I will probably modify my opinions and settings as I get more time on the machine. Right now this is a high price option if all you need is a prospecting unit, but for a person wanting one machine to do everything XP just kicked it up a notch. If they introduce a dedicated gold unit at a lower price similar to the Depar DPR 600 it would be very competitive. For now this is an option for somebody that wants a detector for more than just gold prospecting since the Deus is a superb coin, relic, and jewelry detector. XP DEUS as ultimate "stuff it in a rucksack" metal detector The elliptical coil and rod assembly is just 1 lb 13 oz (1.8 lbs) and so a true featherweight. At 5' 11" I have to run it fully extended and at that it does flex a bit, but I did not find that bothersome at all. A solid coil cover will be good as there are too many coil edges that want to hang up on rubble and sticks. A minor quibble however as the machine is a joy to handle, especially when reaching uphill waist high and higher. A great unit for poking in and around bushes and other obstructions. The coil is hotter at the tips which also helps in poking into tight locations. Early days but the final word is that I am happy with how this coil performs on small gold nuggets after all the wait. Time will tell how it handles the really bad ground and how it fares directly against some of the competition as other people report in. As always giving it time and waiting for a consensus opinion from many users to develop is a wise policy with any new detector. ~ Steve Herschbach Copyright © 2017 Herschbach Enterprises July 2018 - Deus Version 5 Software announced and new X35 search coils announced. September 2018 - New XP ORX announced. Official XP Deus Page (U.S.) XP DEUS 2019 Versions Guide XP DEUS V5 Instruction Manual XP DEUS Versions/Update History Forum Discussion of V4 Update & Coils Forum Threads Tagged "xp deus" XP Metal Detectors Forum XP DEUS V5 Technical Specifications* Internet Price $875 - $1565, 9" Coil w/WS4 Phones, Remote $1520 Technology Induction Balance (IB) Frequency 4, 8, 12, 18 kHz or 14, 30, 55, 80 kHz Autotune Mode(s) Multiple "Reactivity" Settings Ground Rejection Grab, Manual, Tracking Soil Adjust Beach Mode Discrimination Variable, Visual ID, Tone ID, Notch Volume Control Yes Threshold Control Yes Tone Adjust Yes Audio Boost Yes Frequency Offset Yes Pinpoint Mode Yes Audio Output 1/8" headphone socket & speaker, wireless headphones Hip Mount Yes Standard Coil(s) 9" round DD or 11" round DD Optional Search Coils 13" x 11" DD, 9.5" x 4.7" HF DD, 9" Round HF DD Battery Built In Rechargeable Operating Time 20 hours Weight 2.0 lbs Additional Technology Wireless coils, control box, headphones; firmware updates via internet Notes Perhaps the most popular detector sold in Europe *Notes on Technical Specifications - Detailed notes about the specifications listed in this chart.
  24. 2 points
    The Minelab Gold Monster 1000 was introduced in 2017 and is still in production. The GM1000 was created as a relatively inexpensive, easy to operate, high performance metal detector. The Gold Monster 1000 is designed specifically for gold prospecting but may have applications such as micro jewelry detecting. At 45 kHz with both automatic ground tracking and automatic sensitivity settings, the Minelab Gold Monster 1000 is not only very sensitive to small gold but it is relatively easy for beginning detectorists to use. I am fortunate to have been involved in the testing of the new Minelab Gold Monster 1000 prior to its release. One benefit is that I have seen the questions that others have posed about the detector, and now I can answer a few of them. When I use new detectors I always have a goal in mind. I am not trying to pick the detector apart for what it cannot do. Instead, I believe most well designed detectors have something they excel at. My goal is to determine how to use a new detector for maximum benefit. The best way to make that happen is to use the detector in the way it was intended to be used, instead of trying to force it to be something it is not. The key is to be realistic. The Gold Monster 1000 is sold as an entry level single frequency metal detector. Expecting it to outperform detectors costing many times its price is unrealistic. Engineers face a very important choice when designing a single frequency metal detector, especially as regards gold prospecting. What frequency should the detector run at? That choice determines nearly everything else about the detector. In general, low frequencies below 20 kHz handle mineralized ground better, and offer good performance on larger gold nuggets. Higher frequencies over 20 kHz enhance the sensitivity to small gold nuggets, but unfortunately ground handling suffers. The number one question I see asked on the internet is how the Gold Monster stacks up as compared to this detector or that detector. Minelab has actually tried to answer that question directly via the following illustration: Minelab Gold Monster Frequency Range Compared The majority of the single frequency nugget detectors on the market today operate at or near 18 kHz. These detectors handle ground relatively well for non-PI detectors, and have good sensitivity on gram size and larger gold nuggets. They can detector smaller gold, but the smallest gold is not where they excel and the chart attempts to illustrate that. Other single frequency detectors running as high as 71 kHz have superb sensitivity to the smallest gold nuggets, but tend to suffer when it comes to depth on larger gold in highly mineralized ground. Again, the chart attempts to illustrate this fact. The Minelab Gold Monster 1000 engineers decided to concentrate on a frequency that offered the best attributes of the lower and higher frequency extremes. The goal was to design a machine that would attempt to acquire in a single pass the bulk of the gold that machines operating at either extreme could recover if operated together – and yet do it with just one detector operating as efficiently as possible. The catch is that the Gold Monster is still a single frequency detector and it cannot possibly capture 100% of the gold that two detectors operating separately at two vastly different frequencies can capture. If you study the illustration carefully, you will see there is still some gold the 18 kHz detector will do better on, and some gold the 71 kHz detector will do better on. Minelab is not claiming to be able to outperform every other detector under all other circumstances. The goal here is to capture as much of the obtainable gold as is possible with a single detector operating in the most efficient manner possible. Minelab Gold Monster 1000 nugget prospecting detector I have mentioned efficiency because there is more that goes into designing a gold prospecting detector than just the operating frequency. This is where Minelab is attempting to not only make a wise choice in the operating frequency, but to extend the efficiency of that frequency by optimizing the other parameters. First, electrical interference is detected and automatically rejected as much as possible when the detector is first turned on. This helps alleviate interference that could result in less than optimum performance. A great deal of effort has been made into designing a sensitivity control that offers the ability not only to manually tune the detector but to deliver excellent results automatically. The automatic operation is important in ground that varies dramatically from place to place in such a fashion that it becomes difficult – inefficient – to constantly be readjusting the machine manually to retain the best overall performance level. Novices in particular tend to set and forget the sensitivity, leading to a situation where the detector could be running better if the control were optimized more often. The crowning glory of the Minelab Gold Monster 1000 however is the automatic ground tracking system. The 45 kHz frequency is considered to be a high operating frequency, and as such it is subject to possible issues from highly mineralized ground and hot rocks. Manual tuning detectors can have great difficulty dealing with these problems… here is that word again… efficiently. The operator must be on top of and constantly adjusting the machine manually. It is very easy for the operator to be out of sync with the ground conditions and operating at less than optimum performance. At high frequencies having the proper ground balance is extremely critical. Manual ground balance versus automatic ground tracking I will admit I have always tended to distrust automatic ground tracking systems. The theory is they can track out good signals resulting in missed targets. The reality however is the risks entailed by not being properly ground balanced are even greater, especially for novices. The illustration below attempts to show what happens when the operator of a manually tuned detector falls out of sync with changing ground conditions, and then “catches up’ by retuning the machine. The automatic tracking or continuous ground balancing detector however maintains optimum conditions at all times. Even given this evidence in the past however I was a skeptic, and always preferred to manually adjust my detector ground balance controls. That is until I obtained first a Minelab SDC 2300 and then a GPZ 7000 detector. The SDC forced me to use automatic ground balance by offering no other option. A surprising thing happened – I liked it! It worked and it worked extremely well, so much so that when I got my GPZ 7000 it also remains in automatic ground balance mode. The fact is that Minelab has always been a leading developer of automatic ground balancing systems, and I do not think it is being unreasonable to state that they may have the very best ground tracking systems available. The company really has had no choice being based in Australia and developing machines for ground conditions considered to be among the worst in the world. Can the Minelab Gold Monster 1000 go up against the hottest high frequency detectors made and hold its own? Yes. I have personally used the Gold Monster with its 5” coil to easily find nuggets (flakes?) weighing under a grain. Not grams, grains - there are 480 grains per Troy ounce. Remember however that even Minelab in that first chart is telling you that a machine tuned specifically at a much higher frequency will have an edge on at least some tiny gold nuggets. Eleven small nuggets 14.9 grains total, largest 4.4 grains - Smallest at bottom 0.6 grain and 0.3 grain The difference and the serious advantage I believe with the Gold Monster 1000 is in the combination of the superior Minelab ground tracking system and the automatic sensitivity system, designed specifically for the GM1000. In all but the mildest ground operators will find that the Gold Monster is a much more efficient detector that allows more ground to be covered while keeping the machine tuned for the best performance possible. My advice to the old pros that get their hands on the GM1000 is that rather than try and force the machine into operating like your favorite manually tuned machine, seek out instead conditions where that machine struggles. Then trust in the Minelab automatic ground balancing system to compensate for and deliver superior performance under those conditions. Use manual more for targeting specific small areas. Case in point, I took the Gold Monster to a location where hot rocks had given my GPZ 7000 some difficulty. Much to my surprise the Monster was able to automatically compensate for and allow me to operate in those hot rocks and find a couple tiny nuggets too small for the GPZ 7000 to find. The machine was far smoother and I was able to cover ground far more efficiently with automatic ground balance. I followed this up with a visit to a location with wet alkali ground where a high frequency machine would normally fail. I struggled with manual sensitivity for a bit, then threw in the towel and went to the highest Auto+ sensitivity setting. The machine quieted right down and I found a nice little nugget shortly thereafter. Nugget embedded in lump of dirt If the ground allows you can certainly use manual ground balancing to get that hot edge on tiny gold nuggets. The Gold Monster 1000 lacks a standard threshold, but it is easy to set up a pseudo threshold by advancing the sensitivity to where the machine produces some light feedback from the ground. Those who like a threshold can run it this way – others may wish to back down just one notch for silent operation. Old timers like me rebel at the thought of running without a threshold but with the GM1000 it works. The normal reason for running a threshold is to be sure the detector does not fall out of proper ground balance. Here however you can put a superb automatic ground balance to work for you, eliminating that concern. For the very worst conditions, the automatic sensitivity system can augment the automatic ground tracking to allow for efficient ground coverage under conditions that will bring other detectors in this class to a crawl, if not a complete stop. Frankly, if you can’t get the Gold Monster to handle the ground, it is time for a Minelab PI detector or a GPZ 7000. To sum up, I do not want to leave you with the impression that the Gold Monster is the be all and end all of single frequency nugget detectors, and that it will under all circumstances get better performance on every single gold nugget than other single frequency detectors. That is not possible given the limitations imposed by having to choose a single operating frequency. I do believe however that the engineers at Minelab have come as close to this as is possible. The real secret to getting good results with the Minelab Gold Monster 1000 versus the competition will be in leveraging its superb ground handling capability to get the best overall gold nugget performance possible from a single frequency detector. ~ Steve Herschbach Copyright © 2017 Herschbach Enterprises Official Minelab Gold Monster 1000 Page Minelab GM1000 Color Product Brochure Gold Monster 1000 Getting Started Guide Forum Threads Tagged "minelab gold monster" Minelab Metal Detectors Forum Jonathan Porter On Mastering The Minelab Gold Monster Understanding The Sensitivity Control On The Gold Monster 1000 Reports Of GM1000 5" Coil Touch Sensitivity My GM1000 Methodology - Manual Versus Auto Sensitivity Minelab Gold Monster 1000 Technical Specifications* Internet Price $849.00 Technology Induction Balance (IB) Transmit Frequency 45 kHz Autotune Mode(s) Pre-Set Slow Motion Ground Rejection Automatic Ground Tracking Soil Adjust No Discrimination Iron Reject Mode plus Visual Indicator Volume Control Yes 1 - 6 Threshold Control No Tone Adjust No Audio Boost Yes (Always On) Frequency Offset Yes - Automatic On Power Up Pinpoint Mode No Audio Output Speaker & 1/8" Headphone Socket - Headphones Included Hip Mount No Standard Coil(s) 10" x 6" elliptical DD & 5" round DD Optional Search Coils N/A Battery Li-Ion Rechargeable Included, 8 AA Optional Operating Time 20 Hours Weight 3.2 lbs. (with rechargeable battery and 10" coil) Additional Technology The GM1000 automatic sensitivity setting is a feature not seen before in prospecting detectors. Notes Unique rod mounting system allows use of broomstick or other items as a rod. *Notes on Technical Specifications - Detailed notes about the specifications listed in this chart.
  25. 2 points
    Here is a question I received via email, with personal references removed. I prefer to answer these on the forum so everyone gets the benefit of the answer plus others can offer their opinions also. "I am new to metal detecting and, your site here has really helped me out. I have a couple questions that maybe you can help me out with. What are some of the geologic indicators that you look for to determining where to prospect for nuggets? I try to study some of the geology maps but I could use some further pinpointing. I have also been looking at the National map of Surficial Mineralogy. Using the aster and minsat7 maps what are some of the indicators that may point you to higher gold bearing ground? Any help would be deeply appreciated. Could you point me to some old places where you have found gold? I'm not asking to be shown active patches. Just areas that you feel are worked out. I just want to see what gold bearing ground looks like. This would help me to start to learn the commonalities and characteristics of gold bearing grounds. Still looking for that first nugget! Thanks again for any info you can provide." My method is much simpler than that. I basically look for gold where gold has been found before. Think of it like fishing. If you want to go catch salmon you have two options. You can go to where people have caught salmon before - pretty good odds here. Or you can go where nobody has ever caught a salmon before. Very poor odds! So call it prospecting using history to determine where gold has been found before, and then getting as close as I can to those places. History and proximity. Finally, I may then employ geology to narrow that search in a given area if it turns out the gold is confined to certain rock types. The first place I normally turn as a rough guide to any new location in the U.S. is: Principal Gold Producing Districts Of The United States USGS Professional Paper 610 by A. H. Koschmann and M. H. Bergendahl - A description of the geology, mining history, and production of the major gold-mining districts in 21 states. This 1968 publication obviously lacks the latest production figures but it still is a great overview to where an individual prospector can look for gold in the United States. It is a 283 page pdf download so be patient. Pay particular attention to the listed references in the extensive bibliography for doing further research. You can download this here and find many more useful free books on this website at the Metal Detecting & Prospecting Library Principal Gold Producing Districts of the United States So just for fun let's say I want to go look for gold in New Mexico. The section on New Mexico starts on page 200 and here is a quick summary of the opening paragraphs: "The gold-producing districts of New Mexico are distributed in a northeastward-trending mineral belt of variable width that extends diagonally across the State, from Hidalgo County in the southwest corner to Colfax County along the north-central border. From 1848 through 1965 New Mexico is credited with a gold production of about 2,267,000 ounces; however, several million dollars worth of placer gold was mined prior to 1848. Mining in New Mexico began long before discoveries were made in any of the other Western States (Lindgren and others, 1910, p. 17-19; Jones, 1904, p. 8-20). The copper deposits at Santa Rita were known and mined late in the 18th century, and placer gold mining began as early as 1828 in the Ortiz Mountains south of Santa Fe. In 1839 placer deposits were discovered farther south along the foot of the San Pedro Mountains. The earliest lode mining, except the work at Santa Rita, dates back to 1833 when a gold-quartz vein was worked in the Ortiz Mountains. In 1865 placers and, soon afterward, quartz lodes were found in the White Mountains in Lincoln County; in 1866 placer deposits were discovered at Elizabethtown in Colfax County, and silver-lead deposits were discovered in the Magdalena Range in Socorro County. In 1877 placers and gold-quartz veins were found at Hillsboro, and in 1878 phenomenally rich silver ore was found at Lake Valley in Sierra County. The mineral belt of New Mexico is in mountainous terrain that lies between the Colorado Plateau on the northwest and the Great Plains on the east. It is a zone of crustal disturbance in which the rocks were folded and faulted and intruded by stocks, dikes, and laccoliths of monzonitic rocks. Deposits of copper, lead, zinc, gold, and silver occur locally throughout this belt. Some deposits of copper and gold are Precambrian in age, but most of the ore deposits are associated with Upper Cretaceous or Tertiary intrusive rocks. The gold placers were probably derived from the weathering of these deposits. In later Tertiary time lavas spread out over wide areas of the State, and fissures within these rocks were later mineralized. These fissure veins are rich in gold and silver, but in most places they are relatively poor in base metals. In New Mexico, 17 districts in 13 counties yielded more than 10,000 ounces of gold each through 1957 (fig.19). Figure 19 is a handy map showing us where you want to look in New Mexico and also where looking is probably a waste of time. Click for larger version. Gold mining districts of New Mexico The map shows what the text said "The mineral belt of New Mexico is in mountainous terrain that lies between the Colorado Plateau on the northwest and the Great Plains on the east." Sticking to this area is going to be your best bet. Based just on this map I see two areas of general interest - the central northern area, and the southwestern corner of the state. The text mentions that placer deposits were discovered at Elizabethtown in Colfax County, and the map shows that as the Elizabethtown-Baldy mining district. Following along in the text we find this: "The placer deposits along Grouse and Humbug Gulches, tributaries of Moreno Creek, each yielded more than $1 million in placer gold and silver. Another $2 million worth of placer gold and silver was recovered from the valleys of Moreno and Willow Creeks (Anderson, 1957, p. 38-39), and some gold also came from the gravels along Ute Creek. Graton (in Lindgren and others, 1910, p. 93) estimated the placer production of the Elizabethtown-Baldy district prior to 1904 at $2.5 million, and C. W. Henderson (in U. S. Bureau of Mines, 1929, pt. 1, p. 7 40) estimated the production through 1929 at about $3 million (145,138 ounces). The total placer production through 1959 was about 146,980 ounces." The reference material from the passage above is in the back of the book and is where we can get real details. Google is our friend. This stuff used to take me lots of visits to libraries! Anderson, E. C., 1957, The metal resources of New Mexico and their economic features through 1954: New Mexico Bur. Mines and Mineral Resources Bull. 39, 183 p. Lindgren, Waldemar, Graton, L. C., and Gordon, C. H., 1910, The ore deposits of New Mexico: U.S. Geol. Survey Prof. Paper 68, 361 p. Henderson, C. W., 1932, Gold, silver, copper, lead, and zinc in New Mexico: U.S. Bur. Mines, Mineral Resources U.S., 1929, pt. 1, p. 729-759. That is more than enough, but let's also Google placer gold new mexico Lots of great links there, but two jump out: Placer Gold Deposits of New Mexico 1972 USGS Bulletin 1348 by Maureen G. Johnson Placer Gold Deposits in New Mexico by Virginia T. McLemore, New Mexico Bureau of Mines and Mineral Resources May 1994 Notice the source of the last one. Most states with much mining have a state agency involved that can be a good source of information and in this case it is the New Mexico Bureau of Mines and Mineral Resources. That last one is a real gem and contains this passage: "All known placer deposits in New Mexico occur in late Tertiary to Recent rocks and occur as alluvial-fan deposits, bench or terrace gravel deposits, river bars, stream deposits (alluvial deposits), or as residual placers formed directly on top of lode deposits typically derived from Proterozoic, Cretaceous, and Tertiary source rocks (eluvial deposits). During fluvial events, large volumes of sediment containing free gold and other particles are transported and deposited in relatively poorly sorted alluvial and stream deposits. The gold is concentrated by gravity in incised stream valleys and alluvial fans in deeply weathered highlands. Most placer gold deposits in New Mexico are found in streams or arroyos that drain gold-bearing lode deposits, typically as quartz veins. The lode deposits range in age from Proterozoic to Laramide to mid-Tertiary (Oligocene-Miocene) (Table 2). There are some alluvial deposits distal from any obvious source terrains (Table 2). Eluvial deposits are common in many districts; some of the larger deposits are in the Jicarilla district." So now we have a lifetime of ideas on where to go and a basic idea of the geology. And an even better map! Click for larger version. Placer gold deposits of New Mexico Let's look for specific site information. 1. Go to http://westernmininghistory.com/mines 2. Click on New Mexico Mines 3. Click on Colfax County Mines 4. Click on Elizabethtown - Baldy District Here you will find basic site information, references, and a zoomable map with alternate satellite view. An alternate site... 1. Go to https://thediggings.com/usa 2. Click on Browse All States 3. Click on New Mexico 4. Click on Browse All Counties 5. Click on Colfax At this point note you can browse mining claim information or deposit information. Researching mining claims, land ownership, etc. is another topic but here is one source of mining claim location information. For now.... 6. Click on Browse All Deposits or Use The Interactive Map 7. Click on Elizabeth - Baldy A little more detail than the previous site, including this note "SOME FAIRLY COARSE NUGGETS IN WILLOW, UTE, SOUTH PONIL CREEKS, GROUSE AND HAMBURG GULCHES, MORENO RIVER" One more... 1. Go to https://www.mindat.org/loc-3366.html 2. Way down at bottom click on New Mexico 3. Way down at bottom click on Colfax County From here you can dig into all kinds of specific site information but the navigation is a real mess. Have fun! Historic claim staking activity can be a clue. You can get the Big Picture by looking at Mine Claim Activity on Federal Lands for the period 1976 through 2010 OK, that really should have answered your question. As far as places I have been, they are nearly all in Alaska and can be found here Now, I did all the above from scratch with no real prior information on New Mexico in about 2 hours. You can do the same for any state. However, finding where the gold is really is the easy part. The hardest part by far is finding out who controls the land and getting proper permission for access. In Alaska everything is covered by thick ground cover, so opportunities for metal detecting are strictly at creek level, and nearly always claimed. The process there is simple - find out who owns the claims and get permission for access. In most of the western U.S. there is far less or no ground cover, and so getting in the vicinity of and searching around or near mining claims without being on them is a far more viable option than in Alaska. Or you can try and get permission to access the properties. You still need to be able to track down property locations and owners however. For private property I subscribe to and use OnXMaps for my PC, Google Earth, iPad, and iPhone. It quickly maps private property and gives you access to tax roll information about the owners. Tracking down mining claims is easy in the big picture and harder in the details. The Diggings referenced before has interactive claims maps. I subscribe to Minecache for their Google Earth overlay. However, the most comprehensive source with the deepest repository of Land Ownership information is Land Matters. They have online claim mapping with direct links to claims owner information. Note that all online sources have a lag time between the actual staking of a claim on the ground and when it reaches the online systems, if ever. I say if ever because some claims exist solely at the county or state levels and there is no good way to find them short of visiting local recorder's offices or eyeballs on the ground. Prior thread on finding claims information. Finally, I am not the last word on this subject by any means. This is just how I go about it - I hope it helps somebody else. This article was promoted from a thread on the forums. Additional details may be found there via follow up questions and posts. ~ Steve Herschbach Copyright © 2017 Herschbach Enterprises
  26. 2 points
    This is a list of areas open to the public where you can search for valuable minerals in the United States and elsewhere. Many of these locations are free of charge. Others are private mines that charge a fee and yet others are club sites that require club membership. Most of the locations listed are places where you mine the material at the source yourself. Other sites have material you can mine or sort through that has been collected for you. Finally, some of these listings are not sites where you can mine but that may be of interest nonetheless, like old mines of historic interest and museums. A key concern for many is access to places without fear that they are accidently going to be on mining claims or breaking some sort of rule. Many people have families and so areas are desired that are suitable for both the young and the very old. Ease of access is important. Many people are tourists who want to experience some local history and who may know almost nothing about prospecting and mining. Areas that are clearly defined and with easy to understand rules are important. The focus of this section of the website will therefore be to list sites set aside specifically for public mining. Some states have very little information other than general rules and vague hints about where you might prospect. Links are provided to that information to at least get you started. Be cautious working in these states until you have more specific information. Always check the links for the latest information from original sources as things change constantly and material here can easily be out of date. If you have suggestions for additions to this list please contact me with your information. If a site has been listed here and should not be, please notify me to have it deleted. Alaska - Arizona - Arkansas - California - Colorado - Georgia - Idaho - Indiana - Michigan - Minnesota - Montana - New Hampshire - New Jersey - North Carolina - Oregon - South Carolina - South Dakota - Utah - Vermont - Washington - Wisconsin - Australia - Canada - Italy - New Zealand - Scotland Alaska Akau Alaska Gold & Resort (Fee) - New detect for gold operation near Nome, Alaska. Bertha Creek Panning Area - In the Chugach National Forest south of Anchorage. Cache Creek Cabins - Gold panning and dredging on Cache Creek near Petersville. Caribou Creek Recreational Mining Area - On Glenn Highway east of Palmer. Chicken Gold Camp (Fee) - Gold panning, suction dredging and a real bucketline dredge at Chicken, Alaska. Crescent Creek Panning Area - In the Chugach National Forest south of Anchorage. Cripple River (Fee) - The GPAA operation near Nome. Crow Creek Mine (Fee) - Near Girdwood south of Anchorage. Possibly Alaska's most popular public mining site. Dalton Highway - Gold around Wiseman in the Brooks Range. El Dorado Gold Mine - Two hour mining tour near Fairbanks. Ganes Creek Gold (now closed) - World class nugget hunting locale near McGrath in Interior Alaska. Gold Fever Prospecting - Opportunity to run large suction dredges near Chicken, Alaska. Hatcher Pass Public Use Area - Scenic public mining area along the Little Susitna River. Independence Mine State Historical Park - Gold panning at historic old mine. Indian Valley Mine - Historic mine location on Turnagain Arm. Jack Wade Public Gold Panning Area - Non-motorized only in the Fortymile River region. Kennecott National Historic Landmark - Once the largest copper mine in the world. Nome Beach - The famous gold beaches of Nome, Alaska. Nome Creek - 60 miles north of Fairbanks, 4 mile stretch of creek open to hand mining methods. Petersville Recreational Mining Area - Remote but road accessible site north of Anchorage. Resurrection Creek Panning Area - Popular public mining site near Hope, Alaska. Sixmile Creek Panning Area - In Chugach National Forest south of Anchorage. Wrangell-St. Elias National Park & Preserve - Gold pans only! Arizona Bisbee Mining & Historical Museum - Once known as The Queen of the Copper Camps, Bisbee is nestled among the Mule Mountains, an area world renowned for the diversity of its minerals and the wealth of its copper. Lake Pleasant Park - Gold Panning. Lynx Creek Mineral Withdrawal Area - Gold panning and metal detecting for gold. Arkansas Crater of Diamonds State Park (Fee) - The largest diamond ever found in North America was found here. Maybe you can find one larger yet! Sweet Surrender Crystal Mine (Fee) - Dig your own quartz crystal in an operational crystal mine in the beautiful Ouachita Mountains. California Auburn State Recreation Area - Search for gold on two forks of the American River. Columbia State Historic Park (Fee) - Various fee panning opportunities. Empire Mine State Historic Park - The Empire Mine is the site of the oldest, largest, and richest gold mine in California. From 1850 to its closing in 1956, it produced 5.8 million ounces of gold. That 5.8 million ounces of gold would fill a box 7 feet on each side. Himalaya Tourmaline Mine (Fee) - Dig for amazing multi-colored tourmaline crystals! Keyesville Recreational Mining Area - Pan, sluice, dredge and dry wash for gold. Malakoff Diggins State Historic Park - Gold panning along Humbug Creek. Marshall Gold Discovery State Historic Park - Gold panning along the American River. South Yuba River & Merced River - Now closed to dredging but open to panning, sluicing, etc. South Yuba River State Park Project - "Hands and pans" only. Strike It Rich Adventures - Gold panning and mine tours. Colorado Arapahoe Bar - Panning and sluicing at Wheat Ridge, CO. Cache Creek - Non-motorized mining in the BLM Cache Creek placer area. Clear Creek Canyon - Recreational prospecting at Clear Creek Canyon Park. Fairplay Beach - Panning at Fairplay, CO Phoenix Gold Mine (Fee) - Pan for gold at Trail Creek near Idaho Springs. Georgia Allatoona Lake - Pans and shovels only. Consolidated Gold Mines - When you visit, you will be taken on an underground tour of the gold mine by our friendly, knowledgeable staff. Consolidated Gold Mine in Dahlonega was the site of America’s first gold rush. After the tour you will do some gold panning, and gem grubbing. Dahlonega Gold Museum Historic Site - The Dahlonega Gold Museum, located in the old Lumpkin County Courthouse, offers visitors a look at the mining history of Georgia. Gold coins minted in Dahlonega and nuggets – one weighing more than 5 ounces – are on display. Idaho Emerald Creek Garnet Area (Fee) - Look for rare star garnets, found in only two places on earth. Indiana Gold in Indiana - General rules. Michigan Gold in Michigan - Potential locations. Minnesota Gold in Minnesota - General information. ads by Amazon... Gold in Vermont - Information and locations. Washington Gold in Washington - Information and locations. Wisconsin Gold in Wisconsin - Rules and tips. Australia Fossicking and Gold Panning in the Northern Territory - Search for gold, gemstones, crystals and semi precious stones. Gold Prospecting Australia (Fee) - Metal detect for gold in the Australia outback! Museum Victoria - Museum Victoria has an extensive gold collection. The majority of the specimens are from the Victorian and Western Australia goldfields although representative samples from many localities are present. Victoria was famous for the large gold nuggets which were prolific on some of the alluvial goldfields. Unfortunately most of the large nuggets have been melted down, although the Museum has a selection of models of historical and recent nugget finds. Perth Mint - Gold of every description is on display, and watch a gold bar being poured! Queensland Fossicking Guide - Prospecting and metal detecting in Queensland. Sovereign Hill Gold Museum - Discover the beauty and power of gold through one of Australia's most impressive presentations. The Gold Museum houses an extensive and valuable collection of gold nuggets, alluvial deposits, gold ornaments and coins. Canada Britannia Mine Museum - Historic copper mine and museum in Britannia, BC. Dredge #4 at Dawson City, Yukon - Dredge No.4 is located 12.3 km (7.8 miles) up Bonanza Creek Road just outside Dawson City. A tour allows you to explore the massive machine, the largest wooden hulled, bucket line gold dredge in North America. Free Claim #6 - This gold claim is situated “6 above Discovery Claim” on historic Bonanza Creek, in the Klondike Area. It was staked by F. Ladouceur in October, 1896, not long after the famous discovery about half a mile downstream. The Klondike Visitors Association now maintains the claim and visitors are welcome to pan for free and keep the gold that they find. Goldbottom Mine Tour (Fee) - Pan along Gold Bottom and Hunker Creeks. Klinker Opal Property (Fee) - Dig your own opals near Vernon, B.C. Italy Biella Gold Prospectors Association - Purpose is to promote and spread the hobby of panning for gold in Italy. New Zealand Gold Fossicking Areas - Sixteen areas have been set aside in the South Island where anyone can freely enjoy recreational gold mining without the need for a mining permit. Scotland Museum of Lead Mining - The Museum is unique in Scotland as it is the only former lead mine open to the public. Gold panning lessons are also available for a fee. Scottish Gold - The gold found will have lain untouched and unseen since time began! Panners have been finding gold here since the sixteenth century and your day will introduce you to the skills that they used.
  27. 2 points
    From original forum post 5/27/2008 updated 2/14/2010, 1/13/2013 and 1/3/2014 The White’s PulseScan TDI is a ground balancing pulse induction (GBPI) metal detector and as a rule these detectors are considered “dig-it-all” type detectors. The TDI, however, has a number of manual controls that can be adjusted to allow for a degree of discrimination not normally found in PI units. Most normal pulse induction (PI) detectors have a monotone audio response on targets. In other words, the soft threshold tone simply increases in volume in relation to the target strength. All target sound more or less the same, the only difference being a stringer or weaker audio response. This makes things real simple - you just dig everything. Ground balancing pulse induction, or GBPI detectors, employ a method of ground rejection that in current models has an audio side effect. Tones are produced in relation to the current ground balance setting. In the case of the Garrett and Minelab models, a dual tone is produced by a single target. Either a high-low tone or a low-high tone, depending on the target and how it relates to the current ground balance setting. The White's TDI has a simpler response on a single target, either a high tone, or a low tone. The targets and the tones they produce fall into two broad categories. In general one category has low conductive items, like aluminum, US nickels, most gold, and small ferrous trash. On the TDI these items produce a high tone. The other category has highly conductive items including clad, copper, and silver coins, silver rings, some large gold rings and very large gold nuggets, and large ferrous items. The ground balance varies depending on the ground itself but usually is around the same as zinc pennies, and therefore these may read in either category. Other settings, such as the pulse delay on the TDI, can also cause items to vary. The following photo shows how the two target categories break down digging around school yard playground equipment. Coins found with GBPI detector Left side high tone targets, right side low tone targets As you can see in the photo the vast majority of targets produce a high tone response. What is lacking at this location is large nails. Large nails will give a low tone response and so would end up with the coins on the right. Still, by digging low tones only, the vast majority of trash targets can be passed up and excellent results had on deep copper and silver coins. The following photo shows what might result digging low tones only in a park setting. Coins and nails detected with PI Low tone only targets The icing on the cake with the TDI is the Target Conductivity switch. Normally you would have to listen to all the tones the detector produces, the vast majority of them being high tone, to pick out the much rarer low tones that would possibly indicate a deep coin. The Target Conductivity switch allows one response or the other to be suppressed, and by selecting for high conductive low tones only, the TDI operates very quietly in very trashy environments. This value of this feature cannot be overstated, and it makes the TDI a secret weapon for pulling coins out of extremely mineralized ground where VLF detectors would fail. The TDI can go even farther, because unlike the Garrett and Minelab models it features a manual ground balance. This means that in milder ground conditions the ground balance control can be purposefully misadjusted to directly affect target tone responses. This method was passed on to through comment from Reg Sniff and George Kinsey so credit goes to them for turning me on to this. The method involves purposefully misadjusting certain controls to get results and I’m not saying these are the best settings per se. I would encourage more experimentation to see what you can coax from the Whites TDI as I have not seen a detector so prone to experimentation and yet with relatively few controls. This is not a VLF detector and so lessons learned with VLF detectors often do not apply, and in fact could get in the way of understanding the TDI. Have an open mind and experiment. I highly recommend the use of a PI pinpointer with the Whites TDI. You need some serious pinpointing power. The DetectorPro Uniprobe units are very good, but you may need to switch the TDI off when employing the Uniprobe pinpointer if the TDI interferes with the Uniprobe. Coiltek makes a 1” probe with switch box that can use the TDI itself as the pinpointer as another option, along with the more common self-contained pinpointers like the Garrett Pro-Pointer. With the unit powered off, set the TDI Gain at 12, Pulse Delay at 10uS, Ground Balance knob at 1.5, GEB switch On, Target Conductivity On, and then turn the unit Power On. Set for a faint Threshold. If you are getting any interference (uneven threshold, warbles, and funny noises) slowly run the Frequency knob through its range seeking the quietest setting. Then flip the Target Conductivity switch to High. The threshold should go extremely smooth. If you get spikes or noises breaking through the normally rock solid threshold you may need to reduce the Gain. But usually at this point the threshold will be so smooth and solid you will find you can reduce it so low as to be barely heard. Now try waving various steel items and coins a few inches under the coil and note the responses. You will see that most steel and iron, aluminum, and bottle caps will not signal. Beyond that, there are three basic responses. First, hold a coin 6-8 inches from the coil. Note the soft, sweet tone, woo, woo. Listen to it over and over, as this is your deep coin signal. Now run a coin or larger steel item within 1 inch of the coil. You will get an overload signal, a strong baaaaawo, baaaaawo. This is the shallow item overload signal. If you are trying a steel or iron item, increase the distance from the coil. Note that at a certain distance it abruptly cuts off. Now try a coin and slowly increase the distance from the coil. It will gradually turn into that sweet coin tone. The way you tell shallow coins from shallow junk is to slowly raise the coil. If the target just cuts off – junk. If it slowly mellows out – dig! OK, let’s go detecting. What follows is the results of an outing using these settings. Listen for that sweet, deep coin sound. Those are the oldies and you main goal. In some hunted out parks this may be about the only signal you get as there are no shallow targets to generate to overload tone. Just go dig coins. Walk around each target and insure it gives a good, clean response from all angles. Be sure and use proper digging practices to leave the ground undamaged. Please protect our hobby. In other places you will get lots of overload signals. If all you care about is deep coins, ignore them. If you want, however, just raise the coil while sweeping, and if the signal cuts off, skip it. If it fades to the deep coin tone, use your pinpointer and there should be a coin within an inch or two of the surface you can just pop out. The Target Conductivity switch can be set too All to investigate questionable targets and to size targets. A pipe buried horizontally will have a high tone its entire length but a low tone at each end. When you walk around these in the High setting you will only hear the low tone and think it is a coin, but they tend to fade in one direction as you walk around them. If the target seems iffy, switch to All and see if you are picking up the end of an elongated iron or steel item. This false positive can occur well off the end of the pipe and so if you dig and nothing is there you may be off the end of a pipe or rebar. This is where a top notch pinpointer comes in handy. The Pulse Delay seems to be most critical, and if you set in much higher than 10uS the ability to ignore iron is lost. But when it is working right the iron rejection is amazing. Try walking up to a garbage can or other large steel item. You will get no signal until you get close enough to overload the unit. Not only does the unit ignore iron, but nearly all aluminum and bottle caps. The only ferrous target I found was a very rusted bottle opener buried vertically in the ground. If flat it is rejected but the TDI does pick it up if held vertically. I never did dig a bottle cap. I did get two aluminum screw tops that gave the shallow overload and that then sounded like shallow coin when the coil was raised. I got one older aluminum screw cap that was not deep or shallow so I checked it out. I also got positives on two copper wires, two chunks of broken heavy aluminum, an aluminum grommet, and a copper screw cap. Coins found with White's TDI Oh yeah, I found 39 coins. Including three silver dimes and three wheaties so they were not all recent drops. That is 39 coins to 10 trash targets using a PI detector in a turf setting. That is a four to one ratio, and when hunting the deepest targets no worse than a VLF. Better yet, the targets that fooled me were not exactly bad targets by deep detecting standards. There was a time I would have said this was impossible with a pulse induction metal detector. I really did feel most of the junk was iffy but I wanted to check as I am learning. Coins sound oh so sweet and when I’m 100% sure it is a coin it almost always is. What else to say? The GB control is in effect the discrimination control. It is all about setting the Pulse Delay, the GB control, and the Target Conductivity switch to get the best balance of depth and iron rejection. The iron rejection tends to be best at low GB settings, and in high mineral settings best depth is at high GB control settings. If you have no clue what I’m trying to say, you are not ready for the Whites Pulsescan TDI. In high mineral conditions you are trading max depth for max iron rejection. You have to set the unit for the best balance for your conditions. But if you get it right, hold on. This detector is like no PI you've ever used. I have been able to run the Gain very high. I’m sure not everyone can based on where they are. So experiment, experiment, experiment! What about coils? Things might change depending on the coil you use. To summarize the TDI can find coins using two different methods. The simplest is to just run the detector tuned for best depth and dig low tones only. In high mineral ground this will produce coins VLF detectors have been unable to reach while passing on most common trash. The second method makes the TDI into a very effective coin detector, but the misadjustment of the ground balance ends up giving up the extra depth attained with the first method. Still, it does something no PI has ever been able to do before, and that is to find coins with nearly as much efficiency as a VLF detector. I do not want to give the impression I am pushing the TDI as a coin detector. If you want a detector strictly for coin detecting I suggest you get one to do just that. The real point of this article is to highlight that the TDI is a unique detector prone to experimentation. It is a machine for more serious detectorists willing to think outside the box. For those willing to dig some junk and having locations that favor the method, digging low tone targets will find deep coins missed by the best VLF detectors. The main use for the TDI is still nugget, beach, and relic detecting, make no mistake about that. But if you have a TDI , it can pay to experiment with it as there is really nothing else quite like it on the market. Thanks to Eric Foster and White's Electronics. White's TDI Information Page ~ Steve Herschbach Copyright © 2008 Herschbach Enterprises
  28. 2 points
    People talk about how long it took to find their first nugget with a metal detector. Usually the discussion revolves around how much trash they had to dig before they found their first nugget. Well, I probably come close to setting some kind of record for the number of years involved. My problem was not finding lots of trash, it was not finding gold! My first nugget hunt in 1973 taught me one thing about detectors at the time... they were nearly worthless for finding gold. I had my first metal detector, a White's Coinmaster 4. These old units could not ground balance, and had very poor sensitivity to small gold, even with the so-called Gold Probe accessory coil. I was panning 1/2 pennyweight nuggets from the little gully pictured at Moore Creek, and found I could not get a reading from those nuggets when they were placed directly under the coil. My next detector was one of the early White's Goldmasters. I figured I needed a nugget detector instead of a coin detector. Imagine my surprise when I discovered all the Goldmaster was in those days was the Coinmaster circuit board in a larger box! If you are shopping for a used Goldmaster do not buy one of these old ones by mistake. They were blue and about the size of a mailbox. And about as useful for finding gold. I was getting into dredging at the time, and decided detectors were a waste of time for gold. I got into business in 1976 selling mining gear and as a White's dealer. But my stock answer for people coming in looking for a gold detector was "Don't waste your money, you'll find more gold with a $5 gold pan". That was good advice at the time. We concentrated on selling metal detectors for finding coins and relics. My bias caused me not to keep up with changes in the technology, however. Reports of a large nugget finds would appear every once in awhile. I chalked them up to "Yeah, sure you can find gold with a detector, if it's big enough"! And the nuggets found were usually pretty big, not something likely to be found in my immediate area. Steve's First Nugget Hunt 1973 White's Coinmaster 4 with 4" Gold Probe Moore Creek, Alaska The first commercially available detector with ground balancing capability was the White's Coinmaster 5 Supreme. I was seriously into coin hunting, and purchased one of these new units. It was a very low frequency detector, and I found to my dismay that it really liked nails. One nice thing about the very old detectors was that they pretty much ignored nails, They Coinmaster 5 loved them and I was finding so many nails I took a dislike to the detector. But the depth of detection was amazing for the detectors of that time. I sold it to a friend who was a heavy equipment type miner. He found a gold nugget weighing several ounces with it at his mine. This should have clued me in, but once again I chalked it up to being a lucky find of a very large nugget. I went on about my dredging, sluicing, and panning. Finally in the 1980's I was also selling Compass detectors, and I hauled a Compass X-80 up to my claims and gave it a try. It had the capability, as my tests on smaller gold nuggets revealed it was pretty good. We were selling them now as nugget detectors, and some finds were being made with them. Unfortunately, I was not lucky enough to find any gold with the unit the one time I gave it a try. And it just reinforced my feeling about detectors as being a waste of time. It was not until June 18, 1989 that I decided to give metal detecting for gold another try. Compass had repackaged the X-80 as a nugget detector called the Gold Scanner Pro. Here is my log entry for that day: "Went to Crow Creek and used Compass Gold Scanner Pro. Found my first gold nuggets ever with a metal detector! Two nuggets within 10 feet of each other between Area #1 and Area #2 below old tailing pile at lower end. One nugget at 9 grains and the other at 4 grains, total of 13 grains. Also found two bullets." I was hooked! I COULD find gold with a metal detector. It only took me 16 years to find my first nugget with one!! I planned my first real nugget hunt. The destination was high in the Wrangell Mountains of Alaska on some bench deposits above a creek named Bonanza Creek. I had been visiting this area for years and had found lots of nice gold sniping the bedrock in the area. It seemed like a perfect spot to try my new detector skills. I used the Compass Gold Scanner Pro and I set my father up with a Fisher Gold Bug. I used the stock 8" round coil on the Compass, and outfitted my father with a 3-3/4" round coil that used to be available for the Gold Bug. We had a weekend to see what we could do, and so off we went on our first real nugget hunt. Bedrock Exposed by Oldtimers Bonanza Creek has several bench deposits high above the current creek level. These are remnants of stream deposits left high and dry as the stream eroded deeper into the valley bottom. They can often be spotted as flat areas on the valley sides above gold-bearing creeks. In some areas there is more gold in the bench deposits than in the creek itself. The problem for the oldtimers was in getting water up to these locations to work the gold deposits. Ditches many miles long were often dug to bring water along the valley walls from places father upstream to the deposits. They usually used "giants", a term for very large water nozzles fed by pipes with water from the ditch systems to wash the gold free of the hillside gravels. Large areas could be worked in this fashion, with the material being funneled into sluice boxes running down the hill. Much gold was lost in these sluicing systems due to the large volumes of material being washed through the boxes. However the best target for the metal detector operator is not the tailing piles, but the large areas of bedrock exposed by these operations. Nuggets lodged in cracks and crevices as the material was being washed down the hill, and original concentrations of gold in the bedrock were often missed. The only way for the old miners to get this gold would be to tear up all the bedrock and process it. The amount of gold to be had for this extreme extra effort was not much compared to what they would get just going on with their large scale washing operations. And so that gold is left to this day, waiting for someone to find it. Trying to scrape and pan crevices can produce some of this gold, but it is a needle in the haystack kind of search. Metal detectors are the perfect way to locate deposits of gold left in these old workings. The picture above shows a dark area of exposed bedrock we searched with our detectors. Bud Herschbach with Fisher Gold Bug & Steve with Compass Gold Scanner Pro We actually wasted quite a bit of time on bedrock along the creek before heading up to try the bench areas. We only found a few nuggets, and I now attribute this to the fact that most mining activity goes on near the water. People pan and sluice the material along the edge of the water, and dredgers work in the water. The area nearest the creek is the area receiving the most attention. One of the first things an experienced miner must do when getting into metal detecting is to lose this natural desire to stay near the water. What really makes detectors great is you need no water to find the gold, and so working away from the water actually will increase your odds of making finds overlooked by others. You have no choice in desert areas, but in stream valleys do not let the water distract you. Any exposed bedrock or material from the highest ridge on down has potential. We started finding gold, but it was one particular hump of a dark slate bedrock that really started producing gold. My years of coin hunting paid off as I have much better detecting habits that my father. I always keep my coil as close as possible to the ground, and do not raise it on the end of my swings. I am methodical and carefully overlap my sweeps if I feel I am in the gold. My father tends to have his coil off the ground a lot, and wander around with no set pattern. The number one thing he could do to improve his finds would be to slow down and develop better coil control. But as he has often noted, he does not have the patience I do with a metal detector. And he makes good finds nonetheless. Still, technique is important. My father was scanning along up a steep rise in the bedrock. He stepped up the rise with just a couple sweeps over the bedrock. I followed behind, carefully scanning every inch. The bedrock was nearly vertical at one point, and as I scanned the face I got a nice signal. My father was about 20 feet ahead of me when I yelled at him to look at the flat 4 pennyweight nugget I popped out of a crevice in the rock! It turned out to the largest nugget of the weekend, and in fact the largest nugget I had ever found up to that point prospecting for gold. Gold Found by Bud & Steve - from my notes: Large Flat Nugget - 4 dwt 2 grain Fat Pendant Nugget - 2 dwt 8 grain Dad's Big Nugget - 1 dwt 5 grain Sitting Bird Nugget - 16 grain Chunky Nugget - 16 grain Long Flat Nugget - 14 grain plus others total of 11 dwt 6 grain Grand Total 1 oz 4 dwt 12 grain "Great weather, great gold, GREAT TRIP!" Gold nuggets Steve found with Compass Gold Scanner Pro I had a fantastic time. Probably the most fun I'd ever had looking for gold. Metal detecting really appeals to my desire to just get out and walk around the hills. I went nugget hunting regularly after this trip. I tried new machines as they came out, and kept getting better results as the technology improved, allowing me to go back and rehunt old areas many times. My finds close to home really took off when the White's Goldmaster II was introduced, as the local creeks had lots of smaller gold on which the Goldmasters excelled. Still, gold dredging produced the bulk of my gold yearly. I dredged locally, and large nuggets suitable for detecting were rare, although I did finally dredge a 1 ounce nugget at Crow Creek in 1998. Then in 2000 a few things happened to make me really get serious about nugget hunting. First, I finally started getting bored with dredging. I had been doing it so many years it was becoming mechanical. It was mostly an equation. Run the 6" dredge for X hours at X location and get X gold. Dredging was also causing me to stay at the same locations for years at a stretch. I wanted to start moving around more and doing more pure prospecting. I was also finding my body was beginning to suffer from the years of cold water dredging. But the most important thing was those big nuggets. I decided that if I really wanted to see lots more really good-sized nuggets I'd better change my tactics. One 1 ounce nugget in 25 years of dredging meant I was going to die before I found a couple more! So I consciously set dredging aside and concentrated on metal detecting. I sold my 6" dredge and used the funds to buy a Minelab SD2200D. Paired with a White's Goldmaster I figured I could handle most anything. The Goldmasters are very hot on smaller gold, but suffer in highly mineralized ground. The SD2200D is not very good on small gold, but excels on larger gold in the worst of mineralized ground conditions. So the two make an excellent combination for varying gold and ground conditions. Finally, and most importantly, I started contacting miners I've met over the years looking for access to big gold creeks. The payoff was immediate. I found more pennyweight range nuggets in 2000 than I ever had in one year and found my largest ever with a detector at just over 8 dwt. Then in the summer of 2001 at Ganes Creek, Alaska I found a slug of 1/4 to 3/4 ounce nuggets and my largest nugget ever, a 4.95 ounce gold and quartz nugget. I was one of the happiest guys on the entire planet when that nugget came out of the ground! In 2002 I bettered it with a 6.85 ounce nugget and over 2 pounds of detected gold. So there you go. It took me the longest time to warm up to these 21st century prospecting methods. But I am ready now to let the past go and put my pan, sluice box, and gold dredge aside to concentrate on this exciting field of electronic prospecting. I'm more excited now about prospecting than I have ever been, and cannot wait for my next opportunity to test my skills in the field. ~ Steve Herschbach Copyright © 2002 Herschbach Enterprises
  29. 2 points
    My father, two friends, and I flew northwest to the Interior Alaska town of McGrath Friday morning. I have permission to hunt several creeks in the area, but have had a hard time getting there the last couple summers. Bad weather or scheduling has kept me away. Everything finally came together this year, so off we went. My father is a classic Alaska bush pilot with a Cessna 206, so I'm luckier than most when it comes to access. The destination for this trip was Ganes Creek, owned by Doug Clark and Dan Wiltz. Ganes Creek has produced over 250,000 ounces of gold, and some of the largest gold nuggets ever found in Alaska. Some very large nuggets have been found here with metal detectors, and I have wanted to visit the creek for years. After reaching the mine and settling in, Doug pointed us to some old tailing piles. A friend of his, who knew little of detecting, had found a half-ounce nugget in the vicinity, so it seemed a good place to start. I had brought my Minelab SD2200D along, but found the ground to have low mineralization. Bedrock around McGrath is mainly slate/shale. There are lots of igneous cobbles in the overburden, but nothing real hot. Easy detecting ground. The main problem with the tailings was lots of iron trash. I decided to give my Fisher Gold Bug 2 with 14'' coil a try. Since we were hoping for large nuggets, I put it in Iron ID mode, which I normally have not used before. I did find that the machine chattered a lot until I turned the threshold knob down. It appears the threshold control does affect the machine in the iron id mode, although you cannot actually hear the threshold. Tailing Piles Along Ganes Creek Everyone else was using the Tesoro Lobo SuperTRAQ, all outfitted with the 11'' DD coil. Again, due to iron trash, they all ran the discriminate mode instead of all-metal. The Lobo is one of the rare nugget detectors with a full range discriminator. This proved valuable this trip. The control is adjustable, and it is very important that it be set no higher than needed to tune out nails and other small iron items. We ended up finding all the nuggets on this trip while employing iron discrimination. Our theory was simple. There were large nuggets in the area, and we wanted them. Tuning up for the little ones was not the idea. In fact, no one wanted to waste time trying to recover small nuggets and digging lots of worthless iron trash would definitely be a waste of time. I started chasing gold in the early seventies. I've dredged and detected all over Alaska, but spent most of my time in areas where large nuggets are rare. I've always wanted to find a big one, something over an ounce, but it has eluded me. I have made numerous detecting trips to large nugget locales, and detected literally pounds of gold over the years. I have no problem finding 5-7 pennyweight nuggets, but nothing larger has come my way. I finally dredged a .98 ounce nugget in 1998 at Crow Creek Mine, but even then felt like I had not really done it. .98 ounce is close enough to generally say I found a 1 ounce nugget, and I do. But I still did not feel I had hit the big one. So I went ahead and decided to back off on spending so much time dredging, to spend the time chasing hot areas to detect for large gold. A trip to the Wrangell Mountains last year netted me an 8 dwt nugget, my largest with a detector. Then off to the Fortymile last fall. That expedition turned up a 3/4 ounce nugget. Things were looking up. So this adventure was a part of my new game plan. Big nuggets the goal... heck with the little ones! Bud, Steve, Brian, and Jeff My father is always game to go mining, but does not have my passion or patience for it. I bought him a Lobo last year, as the automatic ground balance is right up his alley. The machine is very forgiving. Still, he has sloppy habits, mainly a very poor swing. He is only near the ground directly in front of his feet. I've tried to get him to do better, to no avail. We've searched lots of tailing piles before, with little success. We all start detecting, and in less than 15 minutes Dad gets a beep and kicks the ground. In a very surprised voice, he exclaims, ''I'll be damned... I found a gold nugget!'' There lay a nice 13.1 dwt piece, his largest ever. That got us fired up!. It was the end of the day, but in short order I found a 7.5 dwt nugget, a 1.1 dwt nugget, and .7 dwt nugget. Jeff hit a 2.6 dwt piece. We got some sleep, figuring to strike it rich the second day. But it was not as hot as we had thought. About noon I finally found a quartzy 14 dwt nugget. Since these are nuggets lost by the original operations, many of them have lots of quartz. The nuggets with higher gold content were generally caught. I found a 1.8 dwt, and Jeff hit a 1.3 dwt piece, but nobody else had any luck by 2PM. It was sunny and about 90 degrees. We are not used to such temperatures in Alaska, and everyone of us was suffering. Dad, Brian, and Jeff rolled up and announced it was time to head back to camp for a break. ''Leave me here; I want to keep hunting'' was my reply. Jeff decided to keep hunting. Dad and Brian gave in and decided to stay, but sat down to rest. Jeff and I hit the tailings again, and in maybe 20 minutes Jeff found a nice solid 17 dwt nugget. This rejuvenated the troops and the hunt was back on! Jeff With 17 dwt Nugget Found With Tesoro Lobo We wandered down back trails through the tailing piles, and Jeff finds another 5.6 dwt nugget. Some time later we were detecting some tailings next to the creek, and I hit a nice 15 dwt piece. Jeff and I are pretty happy at this point, but Dad and Brian had no gold for the day. Brian had not found any gold at all yet, and this can be very hard on someone relatively new to nugget detecting. It was nothing but bad luck, as he basically was doing everything right. He simply had not put the coil over a nugget yet. After dinner Brian, Jeff, and I headed for the tailings off the end of the runway. After less than an hour, the mosquitoes were bothering me enough that I headed back out to the runway. Nobody was in sight, so I wandered down the shoulder of the runway swinging my detector. The runway is made out of flattened tailings, so I figured it was worth a shot. Besides, there were fewer mosquitoes in the open! One hundred feet down the runway I get a beep and a 1.7 dwt quartz pebble with a couple chunks of gold in it. I met Brian and Jeff back at camp; they had found no gold. My father returned from exploring up the creek. He also found no gold. Steve With 14 dwt Nugget Found With Gold Bug 2 The third and final full day started with rain. We did some exploring upstream, but with no success. The mosquitoes were out in force, so Jeff and I donned headnets and searched more tailing piles. Dad explored up a side creek, while Brian indicated he wanted to search in the camp vicinity. The rain let up, but not the mosquitoes. They liked the cooler, damper conditions. Jeff and I searched tailings without luck for some time. We finally wandered back to the runway. Jeff finally picked up a couple nuggets on the runway shoulder near where I found the one the day before. I then hit a nice one also. Jeff was hot to get with it, but I convinced him we should go find our partners and tell them about the new finds. I was anxious for Brian to find a nugget. As we got to camp, up wanders Brian with a big grin. He had obviously found gold. A beautiful 7.8 dwt nugget that everyone agreed was the best looking nugget found. Solid gold with just a spot of quartz, and a bit of twisted wire appearance. The find really raised Brian's spirits, and he was raring to go now. Brian's 7.8 dwt Gold Nugget My father was way up a side creek exploring, so we hooked up with the Doug and his crew and did a little instructional detecting. They were getting the idea that maybe these things were good for something after all. My father wandered up as the group headed up the creek. He said he was too tired to go with us, but when I mentioned we had found some nuggets on the end of the runway, he decided to head that way. Jeff could hardly stand it, but we wanted to spend the time with the miners in appreciation of the opportunity they had given us. We finally explained we wanted to go try the end of the runway, and headed that way. We asked Dad how he had done. He says, ''Well, I found one. It's ugly, but kind of heavy. Maybe it weighs an ounce''. He pulls a palm-sized nugget out of his pocket. Our eyes grew wide and we explained to him that the nugget was at least 2-3 ounces. It had a lot of quartz, so it was hard to tell. It turned out to weigh 3.5 ounce. Unfortunately, it appeared to have been run over by a bulldozer. One edge was a clean break with ragged edges of gold hanging out. It is hard to tell, but I'm guessing it is one half of a 7 ounce nugget. Bud excavating a target - is it a bullet or a gold nugget? Gold nuggets Bud found with Tesoro Lobo ST at Ganes Creek We figured the other half was waiting to be found. It was also our last full day, as we were flying back around noon the next day, so we detected late into the evening. All told, we found about 15 nuggets in the runway material, mostly in one area. Brian found a second nugget weighing 2.4 dwt. I ended up with five nice nuggets ranging from 1.3 to 7.5 dwt. Jeff found six from .9 to 4.5 dwt. But we did not find the other half of that big nugget. It was late, so off to bed. Everyone had gold; Brian’s was the biggest he had ever found, Jeff’s was his largest, and my father had hit the jackpot. I was happy, but my largest nugget was a tie for the one I detected in the Fortymile, and still not larger than that .98 ounce nugget I had dredged. Jeff was also been hoping for something over an ounce, but at this point time was running out. I slept poorly that night, waking constantly. I woke a 4AM, and after an hour awake decided to get up. It was light (all night this time of year) and time passes slowly staring at the ceiling. I figured I might as well do a little detecting while I waited for everyone else to get up around 7AM. I wandered off up the creek, mainly wanting to get far enough away so as not to disturb anyone. I went to the first big tailing pile I came to, and covered it pretty well. Nothing at all. So I wandered up the road a bit, and came to a wide set of tailings that appeared to have been pushed up in a pile by a bulldozer. From the looks of it a sluice had been set up, and the bulldozer was pushing tailings to one side. I started scanning along, and near the top of the pile got a strong signal. I dug it up, and peeking out of the soil lay a little gold potato! I gazed at it in disbelief, and picked it up. It was caked in dark soil, but I knew I had finally found the big one I had been looking for all these years! 4.95 ounce nugget found by Steve at Ganes Creek It was still only about 6AM, so I looked an hour longer. I did find another 2.9 dwt nugget a few feet away, but that seemed to be it for this pile of dirt. About 7AM I headed back to camp. Dad and Brian were up, but Jeff was still snoozing away. We got him up, and I did show and tell with the nugget. After washing it up, it came up at 4.95 ounces on the scale. Literally the find of a lifetime, as no other nugget will mean as much to me as this one does. I showed the guys where I had found the nugget, took some photos, and started packing up to leave. I decided I was perfectly content to kick back and relax. The rest of my crew searched my magic tailing pile for a while, but did not find anything. Maybe my find was luckier than I know. In any case, they headed back to the end of the airstrip to search, but only Jeff found a nugget, 1.5 dwt and the last of the trip. Time to go home, so we packed up and flew back to Anchorage. I’m back to work now, and it is hard to believe I found that nugget just yesterday morning. In retrospect, what was so wild about the whole thing was that I had essentially given up on finding the big one this trip as we were basically out of time. Talk about the early bird catching the worm! I found every nugget but one with my Gold Bug 2 set in Iron ID mode. It ignored most trash except for old rusted cans and larger steel items, such as oversized bolts. I dug a pocketful of bullets and shell casings, but they were not so common as to be annoying. I did run my batteries dead at one point, and spares were at camp, so I fired up the SD2200D and found one nugget with it. A nice 1/4 oz nugget at about a foot. But I soon grew frustrated digging trash, sometimes at extreme depth. I have been getting pretty good at reading targets with the SD, but it is nowhere near as good at discrimination as other detectors. I was happy to put new batteries in the Bug and get back to using it. 18.5 Ounces of Nuggets Detected Ganes Creek, Alaska For the low mineral ground we were in, and the desired goal... pennyweight plus nuggets, any good discriminating detector will do the job. My Gold Bug 2 worked well and the Lobo did a great job for the other guys, and is a hard machine to beat for all-around detecting. But all in all, the name of the game on this trip was ''keep your coil low, and keep it moving''! ~ Steve Herschbach Copyright © 2001 Herschbach Enterprises
  30. 2 points
    Winter in Alaska. The days are short and the ground covered in snow. What is a miner to do? It is time to work on the permits. Since we just acquired the Moore Creek property in 2003, the first order of business for 2004 was permitting. We have quite a few things to do before mining can commence, and so I decided to put in for a five year Annual Placer Miners Application for general exploration and facilities work. There are several things we need to accomplish. First, the previous owner left one of our D9 bulldozers stuck about four miles out of camp in a mud hole. We need to get the bulldozer started up and get it unstuck. Since it is outside our claim block, we need a Miscellaneous Land Use Permit for Cross Country Travel to move it to the claims. Once we get the bulldozer into camp, we want to use it to lengthen our airstrip. This needs a plan and permitting. We also want to clear existing trails that have grown over with brush. One thing some people do not understand is that structures on mining claims also need permitting, even if they already exist. We have several cabins on our claims. In these days of lawsuits, abandoned structures represent a liability to the government. Part of the permitting process includes getting a permit to have permanent structures. Things like fuel storage and outhouses must be covered. Then there are the mining and prospecting activities. Our initial operations will be of a small-scale nature, but still they must be described in detail in the plan. The main thing on state land is that activities that disturb less than 5 acres do not require bonding. Any disturbance over 5 acres requires that bonding via the State Wide Bond Pool be obtained. Yearly reclamation reports must be filed for all work performed, even that under 5 acres. Suction dredges need an EPA permit, Corps of Engineers permitting, and possibly a fish habitat permit. Other agencies, like the Alaska Office of History and Archaeology must be notified to review your plan. If this all sounds like a lot, you are right. Moreover, because there are so many agencies to notify, it would be easy to miss something and get in trouble. Luckily, in Alaska the state has a master permit in the form of the Annual Placer Miners Applications (APMA). This one master application is filled out and the state farms it out to most of the various state and federal agencies for approval. Various applications can be made for periods of up to ten years. Aerial view of tailing piles and ponds at Moore Creek, Alaska I filed for a “Multi-Year” Miscellaneous Land Use Permit and Reclamation Plan Approval for five years. There is a $100 fee for the first year, and $50 for the other four years, so the filing fees came to $300. This is a bargain considering all that is done for you in one application. You can find all the paperwork online at the Alaska State Division of Natural Resources (DNR) website. If you examine the forms you will note that they are designed to cover many different scenarios. Just fill out the applicable sections, and draw lines through areas that do not apply. Overall, it is not terribly difficult, and the process has the virtue of making you think through the entire process by asking some questions you may not have thought of. Anyone thinking miners can just go out and tear up the earth without a second thought should read these things. You have to have a plan for filling every hole and ditch and a need a permit for just about everything except breathing the air. Our main permitting covered moving the bulldozer into camp, getting the facilities and fuel storage covered, the use of suction dredges and highbankers for placer sampling, and possible pitting or trenching on the hardrock prospect. We also applied for the ability to upgrade the existing airstrip to make it safer, as it currently is a bit too short for continual safe access. It also is limiting the amount and size of equipment that can be flown in, as it is dangerous to attempt to fly in with anything larger than a Cessna 206. Safety is the main concern over time. You might expect all these permits to take forever to be approved, and for operations that are more complicated, they can. However, our low level of initial activity made permitting easy, and the state of Alaska is doing a fantastic job of getting these things processed. I got the approved permitting back in less than 30 days. Huge kudos to the people at the Division of Mining, Land, and Water. Do remember, however, that it can take longer if you want to do something more complicated, so file well in advance.Overflight of D9 bulldozer stuck on hill The only real surprise I received was from the Alaska Office of History and Archaeology. I had proposed that as part of continuing operations that old pre-existing ditches and other remnants of mining be reclaimed and derelict old structures removed. I thought this would be a benefit in that we would in effect be "cleaning up" after the old miners. You can imagine my surprise when I got a letter notifying me that these old ditches might be historic, and that we should not disturb them. Funny how the ditch I dig today must be filled back in, but if the ditch is old enough, it now must be left alone! The first order of business to consider was the bulldozer move. The overland permit stipulated that the move had to be made by May to take advantage of frozen ground conditions and snow cover. This meant that we must get to the bulldozer in the winter, which presented difficulties of its own. The bulldozer was stuck up to the top of the track on one side, and so would be frozen in and hard to get out. Combine that with the size of the unit, a D9, its age, mid-sixties, and our general lack of operating knowledge, and I came up with what I thought was a good solution. We offered to trade the dozer itself to a local miner on the condition he got it unstuck and did what runway and trail work we needed done before taking the unit off-site back to his own mine. In this way, I figured we avoided the difficulty of not only getting the unit into camp from its current location but got our work done by a more experienced operator. So we made just such a deal. Old D9 bulldozer stuck in soft spot over the hill from Moore Creek Our plan was to acquire a smaller, newer bulldozer that would be more reliable and more fuel efficient for the smaller scale operations we anticipated. But as we researched the situation it became obvious that this was going to get real expensive. Even a used bulldozer was going to run a good chunk of change, not to mention the cost of getting it to McGrath. Then would come the difficult task of getting it from McGrath to the mine, a distance of over 60 miles. That old bulldozer began to look better all the time. But the deal had been made, and so we waited for spring to come. As has often happened in this Moore Creek story, things worked out for the better. The miner was unable to retrieve the bulldozer for us. On one hand I was unhappy to see the opportunity missed for the season, as we would now have to wait until the next winter to move the bulldozer overland. But that was more than offset by the fact that I now realized what a valuable thing a bulldozer is that is already on-site in remote Alaska. We were far ahead to work with what we had. Now it was left to us to get the bulldozer running and out of the hole it was stuck in, and then move it into camp in the spring of 2005. Our runway improvements would have to wait another year Memorial Day finally approached and our first trip to the mine for the season. A new 6” suction dredge was purchased to take the mine for some bulk sampling work, as well as a little 2.5” dredge and small highbanker for more portable sampling efforts. I wanted in particular to sample some of the old tailing piles to get an idea how much smaller gold there was in them. We already knew they contained scattered large nuggets, but if it is to pay to re-mine the old tailings it will be the smaller gold that really makes it pay. The inefficient old recovery methods used at Moore Creek, combined with the large amount of heavy magnetite and chromite in the concentrates, and the clay content of the material, all indicated to me that the gold losses would have been substantial. High of the list was getting the old existing bulldozer trail up to where the dozer was stuck cleared out of brush enough so we could get our Honda 3-wheeler up to it. Four miles over small mountains toting tools, batteries, and whatever else we might need on our backs was not an option we liked. We needed something cheap and small that would fit in the 206, so I shopped around and found a used Honda 3-wheeler. If you ever buy one of these be sure and check the tires because even if the unit is free three new tires is going to set you back a few dollars. Once we got the trail cleared for the 3-wheeler we could then begin the task of getting the bulldozer started and out of the hole. Honda 3-wheeler stuffed in back of Cessna 206 My father and I planned on heading up with a full load of gear in the Cessna 206, and my brother Tom wanted to make his first trip up to the mine. I was excited to have Tom along as his job as a surveyor usually kept him busy summers so we rarely get out together. This made for a full load so I had the 6” dredge shipped to McGrath prior to our departure. We would fly to the mine, open up the camp and deliver our equipment. Tom had to go back to town the third day, so the idea was to fly him to town and then go into McGrath to bring the dredge in the same day. A 6” dredge is more than a single load for the 206 but by staging half the unit in McGrath we saved an extra trip to Anchorage. My cousin Bob planned to come up from Missouri a few days after we left for the mine. He would hook up with a friend of ours, Mike Graves, who would fly them up in Mike’s Super Cub. And so, with plans all made and dredge waiting in McGrath, we finally headed out for Moore Creek. The flight was rather uneventful. When we arrived at Moore Creek, it was obvious that spring was early this year. There were more leaves on the trees than there normally would be on Memorial Day weekend. Usually things are still pretty bare this early, and patches of snow and ice would not be unusual. But as you will see in the pictures the trees are were pretty much leafed out when we arrived. I had been waiting all winter to do some prospecting, and since Tom had a limited amount of time we decided to go prospect the tailing piles. Metal detectors have been effective in determining which tailing piles have larger pieces of gold in them, and presumably smaller gold also. We have been mapping all nuggets found and so a picture of where the hot areas are on the claims has been slowly building up over time. Since I wanted Tom to have the best shot at finding some gold, I loaned him my Minelab GP 3000, while I used the Garrett Infinium. The Minelab has a significant edge in that I have it outfitted with a 24" x 12" Coiltek UFO coil. This larger coil not only gets some extra depth, but probably more importantly allows the operator to cover more ground while detecting. In some ways I think the amount of ground one covers with a detector is more important than an extra inch or two of detection depth. If my detector covers twice as much ground as your detector, I am going to be electronically processing more material than you, even if your detector gets a couple more inches of depth than my detector. Just like when running other mining equipment, it is often about how much yardage you are processing more than recovery efficiency. By the time we got the camp opened up and equipment put away we did not have too much time left. We headed down to some tailing piles next to the runway where a couple nuggets had been found the summer before. It seemed like a good area, but all we dug was small steel trash and bullets. Tom finally found a little 0.13 oz piece but that seemed about it for the spot this time so we headed back to camp. We decided to do a little more hunting near camp and just at the end of the day Tom found a 1.21 ounce nugget, by far the largest he had ever found in his life. Not bad for the first day on the ground, and a short day at that! I, on the other hand, had no gold to show for the day. Tom with Moore Creek gold specimen excavated from tailing pile The next day we decided to head way down the creek to check areas we had not hunted before. In theory the chance for larger gold should diminish as we head downstream, but you never know until you try. We hoofed it on down and did quite a bit of work getting through thick brush in low lying areas. But try as we might we had no luck down the creek. After some time with no success you get the feeling maybe you should wander back to areas where gold has been found before. We did just that, and Tom found a 0.15 ounce piece near Nevada Gulch below the airstrip. Then back to the cabins and he goes and finds a 0.25 and 0.10 ounce pieces near to where he had found the 1.21 ounce chunk the day before. And here I am again on the second day without a nugget to show. It appeared I was on one of my rare cold streaks. Not much you can do about them except persevere. Given the choice I'd rather Tom was finding the gold anyway but it is even better to both be finding gold. My father was not much into detecting this trip and so was doing general camp work and scouting out the trail over to the bulldozer. Tom and I headed off the third day down the the area below the airstrip where Nevada Gulch comes in, and I finally got a couple small pieces, 0.09 and 0.07 ounces respectively. Not very big, but lots better than my time on this trip so far. My father and I got involved in more camp work, but Tom wanted to do some more detecting. I pointed out an area between the cabins and Moore Creek I thought really should have some gold. I had hunted there so far with no results, but the area just felt right. There was some bedrock outcropping there and that seemed like a good sign. And so right at the end of the day Tom goes and finds a 1.64 ounce nugget with my detector exactly where I pointed with my finger when I pointed the spot out! Tom's time was up, and so he and my father flew off to Anchorage the next morning. This also offered the opportunity to fly in another load of equipment and fuel from Anchorage. I on the other hand finally had my GP 3000 back in my possession, and so I headed down and across Moore Creek to try some areas on the far outer edge of the paystreak. In theory the northern side of the creek is where the gold occurs and so by heading over to the south side I was heading in the wrong direction. But gold is where you find it, and I figure any disturbed material at all in an old mine is worth running a detector over. You just never know. And sure enough, I came up with four nuggets weighing 0.08, 0.14, 0.27, and 0.68 ounces, for a total of just over an ounce. This was more like it and it showed gold at the far extreme edge of the old operations. Tom's 1.64 oz and 1.21 oz nuggets showing iron staining common at Moore Creek My father returned, and we made the flight into McGrath to pick up the 6" dredge. This is the Keene model with twin 5.5HP Honda pumps. I like the twins as they are easier to handle than one big pump, and also have the advantage of allowing a person to use one or the other or both pumps for other things. One of the pumps works great on a 4" dredge or as a highbanker pump. So the twin pumps add some versatility to the operation. A 6" dredge is a pretty bulky unit, but we had flown the floats and hose in on the previous two loads. We were able to get all the remaining parts of the dredge into the plane and then on into Moore Creek in a single load. The main reason for the 6" is for use as a sampling device on the many large tailing piles left by the old mining operations. There are several factors that combined to put what I guessed was a substantial amount of gold into the tailings. First, the nature of the gold itself. Even a lot of the smaller stuff has quartz attached, making it lighter and harder to catch. Then Moore Creek has an exceptionally high chromite (chrome ore) content in the concentrates, with some concentrate containing over 35% chromite. Chromite is a lot like magnetite (black sand) in appearance, but is not nearly as magnetic. It is likely the old-timers experienced quite a bit of riffle packing from the heavy concentrates. Another factor is that the decomposed material near bedrock has a fairly high clay content, and much of the material would have clumped and run completely through the box without completely breaking up and releasing the gold. However, years of sitting exposed to rainfall percolating though the tailing piles should have broken down a lot of the clay in the tailing piles by now. Most of the loss was due to the nature of the recovery systems employed. The old operations used long straight sluice boxes with angle iron riffles. They fed everything a one yard at a time into the sluice, including all the larger rocks. They did not screen off the rocks but instead just pitched the larger ones that stuck in the box out by hand. These large rocks created turbulence as the water flowed around them which could blow the gold out of the riffles. And the dumping of full bucket loads caused surges in the flow of material instead of the steady even flow that is desired. All these factors combined meant we have good reason to suspect the 1.5 million yards of tailings at Moore Creek contain substantial amounts of smaller gold in addition to the obvious loss of the larger pieces we are finding with the metal detectors. Since nearly all the tailing piles have large ponds of water adjoining them, a 6" dredge makes for a relatively inexpensive and portable device for testing the tailing piles. Newly assembled 6" suction dredge ready to go to work We used a Honda 3-wheeler and trailer to haul the dredge up to the tailing pond at the upper end of the mine and got it assembled. While we put the unit together I heard a "woofing" noise on the hill behind us. There sat a nice little black bear, watching us and no doubt wondering what we were doing. We watched him and he watched us, and finally he lost interest and wandered of around the edge of the pond. We floated the dredge over to the pile where we had first found a number of nuggets with detectors in 2003. We measured the section of the pile we wanted to dredge to calculate out the yardage so we could come up with a per yard figure of the gold content of the material. The dredging itself was the easiest I have ever done. This particular tailing pile was mostly decomposed bedrock with a few larger cobbles scattered through the material. The pile looks almost sandy on the surface and has little vegetation growing on it, indicating that it came from on or in the decomposed bedrock layer and has little of the organic surface material in it. These types of piles have almost always proven to be a good place to metal detect. I placed the suction nozzle for the dredge just below water level on one end of the pile, and fired the dredge up. A hole was created just below the water line, and then we used picks and hoes to rake the material down into the water where the nozzle just sucked it up. The occasional oversize cobble that appeared was grabbed and tossed before it could get to the nozzle. We ate into the pile, creating an underwater shelf a little over a foot underwater as we moved forward. There is an incredible amount of dredging that can be done at Moore Creek with a pair of knee-high boots and little need to bend over. Basically you just stand there and rake material down to the nozzle. All the material being dredged is actually being dumped back into the bottom of the excavation from which it originally came years ago, so we are in a way we are returning the place to it's original condition by mining it a second time. The old timers dug a hole and put it in a pile; we are taking the pile and putting it back in the hole. About this time Mike Graves and my cousin Bob show up in Mike's Super Cub. The tailing pile we were dredging on is actually an island in the middle of a pond created when the excavation the miners created filled with water. We were using a little inflatable boat to travel back and forth to the island. It was a one person raft, so a person would paddle over while a string was tied to the shore. Once you get to the far shore, someone back where you started pulls the raft back for their use. Well, Bob paddles over with no problem. The trick with these little rafts is to sit or kneel in the middle. But Mike tried sitting on one end, a thing my father had tried previously, and got similar results. Backwards and over into the ice cold water! I really felt sorry for Mike but luckily it was a nice day and the cabins near at hand so he could get out of his wet clothes in short order. We wrapped up our little test dredging operation. A half day of dredging moved approximately 9 yards of material and produced 0.21 ounce of smaller gold or 0.023 ounce per yard. Not counting the larger nugget that might be found now and then it looks like this pile might deliver 1/4 to 1/2 ounce a day of gold if worked with the 6" dredge. This pile had produced nuggets weighing over an ounce while detecting the surface and so it is likely that the diligent dredger would have the occasional day running over one or even two ounces of gold due to this "nugget factor". Normally I would not consider a 1/4 ounce of gold in a day with a 6" dredge to be something I'd get excited about back in my old dredging haunts on the Kenai Peninsula. But there I dredged along with the knowledge that it would be the rarest of things to ever dredge nuggets weighing more than 1/4 ounce in size. That average daily take of smaller gold is all a person can really count on. Here, I'd be a much more motivated dredger knowing that it is almost inevitable that nuggets weighing one to three ounces will be found from time to time. We will never really know just what this will really average out to until somebody goes ahead and works a tailing pile for a couple weeks in this fashion. Suction dredge sampling tailing pile at Moore Creek One thing I know for sure is that in my over 30 years of dredging the largest nugget I've ever found with a suction dredge was a one ounce nugget at Crow Creek Mine in 1998. I have no doubt I could easily break that personal dredging size record at Moore Creek, and so I think in some ways the dredging opportunities here are almost better than the metal detecting. Many people, like my father, prefer to see some kind of reliable, steady gold production. Metal detecting is for the select few who can go for days finding nothing and not get anything and still not get demoralized. But from what I've seen more people are happy getting at least some gold every day as long as they know they still have that shot at a really good day now and then. As the surface areas get detected out this type of steady production work will be more and more important. The main goal for me is to prove enough yardage by this type of testing to justify setting up a small excavator and trommel operation to reprocess the tailing piles. I have had a gut feeling it will pay but I do not buy excavators based on gut feelings. The next morning I got Bob set up with my GP 3000, and Mike had his own Minelab Eureka Gold. I told them about the area below the airstrip where I had found my largest nugget the summer before, a 3.5 ounce section of a rich gold bearing vein. The area had produced a good number of nuggets so far and the area was regarded as the "hot spot" on the creek by the previous owner. I had good reason to believe the area still held good promise, and Mike and Bob headed down to check it out. My father and I moved the dredge over to the next closest tailing pile. This one looked distinctly different from the other pile. It had more cobbles and rocks and more vegetation growing on the surface, indicating that it contained more overburden than the other pile. Yet it had produced some nice nuggets with the detectors also so I was curious how it would prove out with the dredge. We worked away at this new tailing pile. This one was much taller, and so the face of the excavation got to be over 10 feet tall. It is important not to undercut the material adding to the risk of falling rocks or a complete collapse of the material, and so we found ourselves standing high above the water raking material down to the nozzle below. Careful raking and the tossing out large rocks before they could fall to the nozzle made this work remarkably well. We threw all the rocks into a zone between the island and the edge of the pond with the idea of eventually creating a causeway that would allow us to walk over instead of using the little raft. The pond is deeper than it looks and so it will take some time but I've always found it to be beneficial to direct rocks to a certain area than just tossing them randomly in every direction. Bob and Mike showed up halfway through the day, and as Bob stood on the bank of the pond he held up something big to show us. We paddled over to check it out, and it turned out Bob had gone right to the area I had sent him with my detector and found the largest specimen we've located at Moore Creek to date. A 5.13 ounce chunk of what appears to be a perfect cross section of a rich gold-bearing vein. Just like the type of vein I'm dreaming of finding on the hill above our claims. It is exciting to find this kind of large gold specimen, but more exciting for me is what they keep telling me could exist elsewhere on our claims. These specimens have not traveled far at all from their source. Bob was of course ecstatic at having set the Moore Creek record for our group, but since nuggets up to 20 ounces have been found in recent years and up to 100 ounces in the early days his glory may be short-lived. I have since performed a specific-gravity test on the specimen, and it consists of 2.94 ounces of quartz and 2.19 ounces of gold. Some exceptionally rich gold ore indeed. Bob Herschbach and his 5.13 ounce specimen Close up of 5.13 ounce gold specimen seen on edge 2011 Update: I purchased the specimen from Bob. The gold was only visible around the edges and so I tried an experiment. I ground the specimen down on all sides until gold was visible, and then put a partial polish on it. The quartz is partially translucent so you can actually see below the surface and see gold enclosed in the quartz. The price of gold increased enough that I finally sold the specimen. 5 ounce gold specimen ground down and polished to better show gold We wrapped up the dredging for the day as soon as we moved about the same 9 yards of material as we had from the other tailing pile. This time there was only 0.11 ounce of gold to show for the work, and so it was obvious this pile did contain more of the worthless overburden material than the other tailing pile. This calculates out to about 0.012 ounce per yard. Nothing to get too excited about with a dredge but an excavator with a one yard bucket it would add up. Since this material is already sized and stacked and next to an existing tailing pond/settling system the cost to process it is much lower than it would be to process virgin material. A good trommel system should also get better small gold recovery than a 6" dredge. More sampling is needed but the initial results so far look very promising with at least some small gold to be found, without consideration of larger nuggets. A couple days of dredging left me feeling like doing some detecting. Even that easiest of dredging operations was a lot more work than swinging a detector. We got in a coupe hours before turning in for the evening, and I found a 0.09 oz nugget and my father found a 0.29 oz nugget. The real chance would come the next day, our last for the mine on this trip. We loaded up the next morning and headed down to where Bob had found his piece. It was one of those chunks myself and others had walked within feet of. And like most nuggets, this one, although found with a Minelab GP 3000, was shallow enough that any detector at all would have found it. Bob just got his coil over it first. We all started hunting, but results at first were pretty slim, with me finding a few smaller pieces. It got very hot, and everyone started running out of energy as the temperatures climbed. I finally wandered off down the creek on my own and back into an isolated little area back in the brush. And boom, up comes a 1.93 ounce specimen! I got really excited, of course, and in short order I found another piece weighing 0.28 ounce. It was time to call in the troops so I climbed a nearby tall tailing pile and yelled away for the other guys to come over, but could not hear anyone reply. I hiked on over and rounded up Mike and my father, but Bob had already returned to camp. Unfortunately I had broken the spell, and try as we might my new area dried up. I ended up with the gold of the day, with the 1.93 oz and 0.28 oz pieces, plus 0.18, 0.09, 0.07, 0.08, and 0.05 ounce pieces for a total of 2.68 ounces . That put me over 4 ounces for the trip, but Bob beat me for total weight, most gold, and largest specimen so far, all in one find! 4 ounces gold specimens found by Steve at Moore Creek The pictures above show my finds for the week, plus the 0.35 ounce of gold dredged from the tailing pile shown below. The pictures are not to scale; my specimens that are shown too small as the dredged gold is closer to life-size as seen in this picture. Those larger pieces found dredging would brighten most people's dredging days. As you can see even the smaller gold is very rough and has quartz attached. This gold has not so much rolled down the creeks as it has just rotted out of the rock and so there are going to be lots of pieces with quite a bit of character to them. The only real downside to this gold is the quartz content does not make it very amenable for jewelry work, as the quartz tends to pop out when heated. Gold found while suction dredge sampling the tailing piles All in all a very good start for the year. We got our propane refrigerator working but were frustrated by the 3 kw diesel generator. The darn thing has a hand crank starter and although it would pop and cough we could not get it running. It appeared to be some sort of fuel supply problem, but take apart what we may it just would not run before we all got so tired of cranking we gave up. The dozer problem remains to be tackled. Getting the dredge on site was a big plus, as getting good volume samples is critical in deciding just where and how to set up larger scale mining operations. I'm a very cautious miner in that regard. I do not believe in proceeding with any kind of serious mining without sufficient yardage blocked out and proven in advance. Too many people think that is time wasted and just jump in and start mining, but that is why the vast majority of mines go broke. We will block out enough pay to make whatever operation we go with have a high probability of turning a good profit. Part of that will be determined by exactly what equipment gets used in the actual mining operation, which also gets determined by the sampling program. Final lesson for this trip - if I ever loan you my detector and point you in a certain direction, you'd better head there! Both my brother and cousin got their best finds ever on this trip and I was glad to see it. The next best thing to finding a nugget or me is seeing other people find them. The happiness is contagious whenever gold is being found in our camp, no matter who is doing the finding. ~ Steve Herschbach Copyright © 2004 Herschbach Enterprises
  31. 2 points
    I walked a little ahead of my detecting buddy Jeff as we searched along the bulldozer trail for gold nuggets. The bulldozer had pushed little berms of material along each side of the trail as it made its way through the old tailing piles. I swung off the trail to one side where the tailing pile sloped down into the brush. Sweeping my White's MXT over a moss covered cobble pile resulted in a loud beep. I peeled the moss and cobbles back with my pick and looked down at the largest gold nugget I have ever found! This story actually starts in 1972. That is when I purchased my first metal detector, a White's Coinmaster 4. I put in lots of hours with that detector, finding thousands of coins in Anchorage, Alaska, in the days before metal detectors became more common. I was already doing a little gold prospecting and so I just had to try my new detector out for finding gold nuggets. I purchased a little 4 inch coil touted by White's as being the hot ticket for finding gold. They actually called it the "Gold Probe". However, after a couple outings I discovered that the detectors of the day were just not up to the task. The inability of the early units to compensate for ground mineralization made it impossible to find all but the largest nuggets. I am sorry to say that these large nuggets were very uncommon in my area, and so the chances of my finding gold with the early model detectors were slim to none. Steve in 1973 on very first nugget hunt - Moore Creek, Alaska & White's Coinmaster 4 This early experience caused me to overlook metal detectors as a practical mining tool for many years. In fact, when my partner Dudley Benesch and I got into business in 1976 we sold metal detectors from the start but strongly downplayed their usefulness for prospecting. My standard line was "you can probably find more gold with a $5.00 gold pan than a $500.00 metal detector". During the 1980's, I was heavily involved in gold dredging, so much so that I did if full-time for a couple of years. The amount of gold I thought I might find with a metal detector seemed trivial compared what I was producing with my suction dredges. I continued coin detecting from time to time but did not spend as much time at it as I had previously. It was at this time that stories of fabulous gold finds in Australia started to appear. My attention returned to using metal detectors to find gold nuggets, and I finally found my first nuggets with a Compass Gold Scanner Pro in 1989. I was still selling metal detectors as a dealer and it was about 1990 that White's introduced its breakthrough Goldmaster II. At an operating frequency of 50 kHz, it was by far the most sensitive detector available for smaller gold nuggets. The Anchorage area has lots of gold but it is mostly in match head size and smaller nuggets. Nuggets weighing up to one-quarter ounce are very rare and nuggets weighing an ounce or more are almost unheard of. The Goldmaster II opened up the local area to nugget detecting with its small gold sensitivity and ease of operation. Put all this together with its bargain retail price of $499.95 and the Goldmaster II quickly became one of the fastest selling metal detectors ever. It is one of the only detectors I ever sold that quite literally could not be produced fast enough to meet demand. I contributed to this electronic gold rush by taking my new Goldmaster II to local gold mining sites and finding thousands of gold nuggets with it. One popular site, Crow Creek Mine, had produced only small numbers of nuggets with other metal detectors. However, the Goldmaster II and its successor, the Goldmaster V/SAT, appeared be the perfect detectors for Crow Creek. The creek has only moderate mineralization and tremendous amounts of the smaller gold the White's units could find so easily. All of a sudden it seemed like gold was pouring out of the mine, all due to the introduction of the Goldmaster models. Steve with White's Goldmaster II in 1992 Jeff was managing our Mining Department at that time, and if anything, he was even hotter than I with the Goldmaster. We were both having a great time finding gold and posting photos of our finds at the store. The Goldmaster models got so popular at Crow Creek that problems started occurring with so many people running the same frequency unit in the same area. Detectors running at the same frequency interfere with each other electronically, and it got to where people would have to take turns running the detectors at some of the more popular locations at Crow Creek. This problem was finally solved with the introduction of the Goldmaster 3 and its frequency shift control. Despite these successes, gold dredging still occupied the majority of my free time in the 1990's. I was using a 6-inch dredge as my production unit, and the consistency with which I produced gold with it could not be matched by the more sporadic success one has with a metal detector. That, and the finds at Crow Creek and other local sites were depleting and so more and more time and effort was required to be successful detecting gold in these areas. A couple things about my dredging bothered me however. One was that I was finding good quantities of gold but I was finding very few large nuggets. It was not until 1998 that I finally found a 1 ounce gold nugget while gold dredging. My use of larger dredging equipment was tying me down to local areas where large nuggets are very rare. I really wanted to be able to find a monster nugget like I would read about other people finding. Second, I was spending all my time going to the same nearby areas, over and over again. Days, if not weeks, were spent working in the same stretch of creek. I wanted to get out and spend more time exploring remote areas of Alaska. I became convinced that if I wanted to get serious about gold and prospecting I needed to get away from the local area. Therefore, I made a conscious decision in 2000 to focus on metal detecting as a prospecting method instead of suction dredging. I sold my mining claims near Anchorage and my 6 inch gold dredge and invested the money in new metal detectors. I have used all the various brands over the years and found each one has strengths and weaknesses. In my opinion one key to successful nugget detecting is to have a variety of machines with differing capabilities. I invested in several makes and models of metal detectors that I use depending on particular nugget detecting tasks. I was amazed with the results of my new strategy. Not only did I see no real decline in the amount of gold I was finding each year, but my nugget finds blew away decades of dredging results. I was finding more gold nuggets weighing over an ounce than I had thought possible. My previous record of a 1 ounce gold nugget from Crow Creek Mine was totally eclipsed by 4.95-ounce nugget from Ganes Creek in 2001. Finding that nugget was one of the biggest thrills of my life! The real secret proved to be the freedom afforded by my metal detectors. With only a few pounds of gear to pack, it became far easier to go to remote Alaskan sites where large gold nuggets are found. It helped tremendously that I have developed many contacts with miners in my years of business and as a member of the Alaska Miners Association. These contacts are helpful when it comes to getting access to nugget producing mining claims. The fact is that most of the good locations for nugget detecting Alaska are on mining claims and so getting permission from the claim owners is critical. Ganes Creek is in west central Alaska near the town of McGrath. Ganes Creek has produced some of the largest gold nuggets ever found in Alaska, including a 122 oz monster. The creek has a long mining history and so has many miles of tailing piles from old bucket line dredge operations, and from more recent heavy equipment operations. It was at Ganes Creek that I found my 4.95-ounce nugget and numerous other gold nuggets in the 1 to 2 ounce range in 2001. Fall colors and old tailing piles at Ganes Creek, Alaska With some prodding on my part the owners of Ganes Creek decided to give a "pay to detect" operation a try. Opportunities to metal detect at places like Ganes Creek are rare, especially for people from outside Alaska. As part of the effort to get the word out about the operation, I received permission to bring a couple "key players" in the detecting industry up to Ganes Creek for a short visit. The idea was that once they saw the potential firsthand they would no doubt spread the word to others. In the spring of 2002 I decided to organize a Gold Show at Crow Creek Mine near Anchorage. We had never done this type of show in Alaska before and I thought it would be fun for all involved. Little did I know the work that goes into making a show like this come together. It proved to be a massive undertaking, but a rewarding one. One key to a successful gold show is to try to convince manufacturer representatives into making the expensive trip to Alaska. We received a lot of support from various suppliers but that shown by White's Electronics and its Alaskan distributor Renton Coin Shop was truly exceptional. Many accessory items and gold coins were donated as prizes to be given out for various activities of the gold show. Most impressive was the latest version of the White's Goldmaster, the new GMT, which was donated as grand prize in the detector hunt held during the show. This was very fitting, as there have probably been more Goldmasters at Crow Creek over the years than any other single model of metal detector. The generous donations were greatly appreciated by everyone attending the show. I would like to offer particular thanks to Mary Gladding of Renton Coin Shop for her enthusiastic support. Steve Houston of White's Electronics had come up for the gold show, and so I took the opportunity to arrange a trip up to Ganes Creek. Steve is an avid nugget hunter and so he jumped at the opportunity. I arranged for a visit immediately after the Gold Show ended. Steve had never been in a small airplane before, and so the bush plane flight into Ganes Creek from McGrath was an adventure in itself for him! Having flown in small planes my whole life, I underestimate the effect swooping low over the terrain and landing on small runways has on the inexperienced flyer. After we arrived at Ganes Creek, we did a bit of metal detecting in the immediate camp area, as quite a few gold nuggets had previously been found right around the cabins. The whole camp is built on old tailing piles that have been flattened out. After a little time spent with no results, we decided to head upstream. The first group of 10 visitors was already at the mine, and two nuggets weighing over 5 ounces each had been found the day before. The nuggets were found just upstream of a large drainage ditch that had drawn my attention the last time I had visited the mine. The ditch is piled high on both sides with excavated material. I reasoned that the piles might contain some nuggets, since the material from the bottom of the ditch was from deep below the surface. We started detecting the area, and in an amazingly short time, I heard Steve yell that he had found one. Sure enough, scanning the sides of one of the piles with his GMT produced a chunky 3.2 oz gold nugget! Well, that was so easy we figured there must be a bunch of nuggets along the ditch. However, as much as I tried I could not find a nugget myself, and Steve's initial find remained his only find. As if he really cared! I finally wandered away and found a small gold nugget on a large tailing pile nearby but that was it for the day. Steve Houston with 3.2 ounce gold nugget found at Ganes Creek with White's GMT This was a very short trip and so we only had the following day to try and find more gold. I found a few more small nuggets and Steve found none. Searching tailing piles for gold nuggets is literally like looking for the proverbial needle in a haystack. Entire days go by with no finds, but when gold is found it tends to be worth the wait. I was grateful Steve Houston found a nugget as large as he had in our limited amount of time. It was the largest nugget he had ever found, and better yet, larger than anything his regular hunting buddies had found. More than 30 people visited Ganes Creek in the summer of 2002. Over 10 pounds of gold was found, with many nuggets weighing over an ounce and several in the 5-ounce range. The success rate was amazing; with a large majority of the visitors able to say they found the largest gold nugget of their lives at Ganes Creek. Still, people started to wonder if the creek was "worked out" and that all the nuggets had been found. I scoffed at this idea, as I have seen even small parks produce old coins missed by decades of diligent metal detecting. The idea that a few dozen people could find all the nuggets to be found in many square miles of tailing piles is not something experienced detectorists would worry about. To prove the point, I put the word out that I would make a visit to Ganes Creek after all the visitors had been there that summer and go find some gold. OK, I have to admit there was a certain amount of bravado in this. The fact is that detecting tailing piles is very much a hit and miss proposition. In general, sheer hours of diligence will pay off, providing the nuggets are there to be found at all. However, there also is a bit of luck involved, and sometimes even the most dedicated person will get skunked. If it was easy we would all be out swinging a detector looking for gold nuggets for a living, but that is not the case. So, although I was talking big I certainly had my doubts about how much gold I would find. It was late in the season when Jeff, Brian, and I made that final 2002 visit to Ganes Creek. Brian is an avid gold dredger and so his focus for the trip was to do some exploratory gold dredging. Jeff and I were both hot to go detecting for gold, however. As I noted before, Jeff is a very accomplished detectorist, and we usually have a cheerful competition going while nugget detecting. We brought along several different detectors to try. I had my GMT but also White's new MXT model. I was intrigued with this machine that combined the basic Goldmaster circuitry with the features normally found on high-end coin detectors. I figured its exceptional target ID features might prove useful in the trashy tailing piles, and especially around the camp area. Jeff and I traded machines back-and-forth to get a feel for how the different detectors worked at Ganes Creek. Jeff in particular was in the market for new unit, and so was most interested in trying them out comparatively. Jeff with White's MXT at Ganes Creek, Alaska We first headed back up to that ditch area where many of the large nuggets were found, including Steve Houston's. The area had been hammered hard all summer, but we figured there might be some gold left to be found. I located a 13.8 dwt (dwt = pennyweight) nugget, and then a 3.8 dwt nugget (20 pennyweight per ounce) the first day. Jeff, although he tried in earnest, came up with no nuggets. We also tried some old tailings upstream farther, but found no more gold that day. The second day dawned under rainy skies. We decided to stay near camp, and see if there were more nuggets waiting to be found around the cabins. I grabbed the new White's MXT, while Jeff used the GMT. The rain poured, but we stuck with it. Lots of bullets and shell casings were dug, which I consider a good sign. You cannot get all the nuggets and leave bullets in the ground. However, by the end of the day we had no nuggets. We headed up to the bench deposits above camp and found some small nuggets, just so we could say we did not get skunked. Jeff found a nice little pennyweight nugget, and I got a few smaller bits. Nothing to brag about, but at least we could say we found gold. I have to note that I was very impressed with the MXT around camp. I used the 6" elliptical coil, and ran the unit in the relic mode. This mode, when set up a certain way, gives a high tone on non-ferrous targets, and low tone on iron targets. It was easy and efficient around camp, and all the targets I dug were non-ferrous items. It has very good trash separation with the small coil, and easy target ID with the dual tone system. The machine was great for places where trash is literally inches apart. The weather cleared the third day. Jeff again ran the White's GMT, and I the MXT with the small coil. We started in camp, and I found a small nugget just behind the cabins. We then tried some of the dragline piles above camp near where I found my 4.95-ounce nugget in 2001. I switched the MXT to the 950 9.5" coil. Both Jeff and I found nuggets weighing several pennyweights each. So far we were not exactly knocking down the nuggets. Frankly, we were both a bit puzzled, as our constant digging of bullets indicated nuggets were still to be found. If an area were thoroughly detected we would be digging nothing at all. Nevertheless, our nugget results were lean, and so our enthusiasm was flagging. I am a big fan of aerial photos, and had some new ones showing an area downstream opposite the old bucketline dredge machine shop. Long rows of old bucketline tailings ran far back away from the road, and so I suggested we run down and check them for a change of pace. Jeff was running the White's GMT with the Sierra Max 14" coil, and I ran the MXT with stock 950 coil. The more I used the MXT the more I liked it. On the cobble piles I ran in prospect mode, with full gain, minimum V/SAT setting, and in automatic ground balance. The 14.7 kHz frequency ran smoother on the mixed rocks of the cobble piles than the higher frequency GMT. High frequency detectors tend to get weak signals from mineralized rocks because of their extreme sensitivity. The MXT seems well suited for searching areas of mixed mineralization due to its lower frequency and fast automatic ground balance. We followed an old bulldozer trail back towards the area I had spotted in the aerial photos. I concentrated on the edges of the main trail near to and in the brush. My goal was to cover obscure areas others may have missed. I finally got a good clean signal and gave a couple digs with my pick. The moss and rocks flipped back, and there lay a large gold nugget. I did not get as excited over this one as with my 4.95 ounce nugget of the previous year, as I was not sure exactly how much the nugget weighed. Jeff, however, knew immediately it was something to jump up and down over. And he was right, as upon weighing it came in at 6.85 ounces! My largest nugget ever, and the largest found at Ganes Creek that summer. I also had the satisfaction of proving that finds always remain for those willing to look. This particular nugget is strange, with very dark, lustrous quartz encasing a solid gold core. The quartz is almost like agate. Fingers of dendritic (leaf) gold reach up from the gold core into the quartz shell. It is a unique nugget, unlike any I have seen before. And at 6.85 ounces it gives me entry into a very exclusive club. Few people can say they have found a gold nugget weighing over one-half Troy pound without heavy machinery. Steve with 6.85 ounce gold specimen from Ganes Creek found with White's MXT My White's MXT had paid for itself rather spectacularly. It is hard not to like a detector that finds a big gold nugget. However, while it bench tests well on small gold, frankly it does not hold a candle to the White's GMT when it comes to very small gold under actual field conditions. If small gold is your bread and butter, the GMT is still the way to go. Not only do higher frequency detectors have an innate edge on tiny gold nuggets, but also the manual ground balance on the GMT offers better control for small gold. The MXT must be auto ground balanced, then "locked". The GB point is then fixed, but it cannot be manually adjusted from there. The GMT has both automatic and manual ground balance. The MXT does do very well on nuggets weighing a few grains or more, and the bigger the gold gets; the less difference there is between the MXT and GMT. Frankly, for nuggets weighing in pennyweights or more, I actually prefer the MXT. It operates smoother than the GMT in mineralized ground, and has depth as good as, and maybe under some circumstances better than, the GMT. It is a great machine for large nugget hunting. Combine that with the fact that it has a superior target ID system, with both iron readout and conductivity measurement, and you can actually do things like tell most gold nuggets from a .22 shell casing. I used the relic mode with the small coil on the MXT to work extreme trash areas to good effect. This machine has lots of potential to explore, and yet is very easy to use. Add in the fact that it has a 6.5" x 4" elliptical DD, 5.3" round concentric, and 10" x 5.5" elliptical DD coils available as options, and I think the MXT is now the machine to beat for all-around use. Coin, nuggets, relics, and jewelry... it does it all. Moreover, despite its wealth of features, the list price is only $799.95. This article may seem like a White's ad, as I have purposely made the brand a centerpiece of the story. The fact is that I have owned and used all the major brands of detectors and continue to do so. I think all the major manufacturers make good units; Nevertheless, White's will always hold a special place in my heart as being the first brand I ever owned. It was that White's Coinmaster 4 that got me started metal detecting all those years ago. To come full circle 30 years later and find the largest nugget of my life (so far) with a White's detector is particularly fitting. You may contact me online at the DetectorProspector Forum if you have questions regarding this article. ~ Steve Herschbach Copyright © 2004 Herschbach Enterprises
  32. 1 point
    The XP metal detector company has announced a new model for late 2018 called the XP ORX. This new model appears to be a refined version of the XP manufactured Depar DPR 600. The DPR 600 was made to take advantage of the African gold rush by offering a model designed primarily as a gold prospecting detector with other uses taking a back seat. I personally think the Depar DPR 600 was used as a proving ground for the new high frequency (HF) coils while also offering an opportunity to fine tune the Gold Field program. My expectation all along is that XP would eventually release a similar model for sale outside of Africa. It looks like after almost two years that new refined version of the DPR 600 is available for purchase as the XP ORX. This introduction is so new that information at this time is limited - everything here is subject to change as new details emerge. For now what we know for sure is that the XP Orx will be available in two configurations. The versions are basically the same, with a wired headphone version for 700 Euro, and a wireless headphone version for 800 Euro. U.S. pricing is unknown at this time but $799 and $899 is probably in the ballpark. You can choose either the 9" round HF coil or 5" x 9.5" elliptical HF coil. There is no exact word on availability yet, but presumably we will be seeing this model available for purchase in early 2019. XP ORX gold prospecting metal detector It is possible hints about the new XP Orx can be gleaned by reading the DPR 600 User Manual. One main difference is in the User Modes. The DPR 600 and XP Orx both have four preset programs plus two user custom program slots for saved programs. The programs on the DPR 600 are designated as 1. General 2. Large Gold 3. Fine Gold 4. Iron Discriminate. The XP Orx is designed for a bit wider appeal, and so it looks like the General and Iron Disc modes have been recast as coin hunting modes. The modes on the XP Orx are 1. Gold 2. Fine Gold 3. Coin Fast 4. Coin Deep ORX Key features: HF coil technology (21 Frequencies ranging from 13 to 81kHz). Extreme sensitivity to small targets with high frequency 50kHz and 81 kHz. 4 factory programs: Gold Prospecting (x2) – Coins and Relic (x2), + 2 user. Trusted XP fast wireless technology: Coil – Remote – Headphones – MI-6. The all new “WS Audio®” compact wireless headphone receiver. Re designed ultra-light Telescopic “S” stem. The lightest machine on the market at only 770grs (remote hip mounted). Easy to operate with a user-friendly interface. Wireless connectivity to the MI-6 pinpointer + advanced remote settings. Lithium batteries, giving up to around 20 hours of detecting. Easy to charge with any certified USB charger or via computer (XP USB charger optional only) Available with a choice of HF coils – 22cm (9") Round or 24/13cm (9.5"x5") Elliptical. Compatible with the X35 coil range (22, 28, 34/28cm). Software Update (remote control via USB cable). Go terrain mobile app compatible (coming 2019). 5-year warranty – Made in France. Affordable price – Suggested maximum retail price: 699€ including taxes – 799€ including taxes with wireless headphone (WSA). Note that the upper armrest area of the rod has been redesigned and is different than the existing Deus rod assembly. XP ORX Controls & Settings ORX settings: 99 levels of sensitivity 21 frequencies (13 kHz to 81 kHz). 99 levels of discrimination + 5 levels of IAR Discrimination in Gold programs. 20 levels of Threshold. 4 levels of Reactivity. Iron Tone with Pitch audio (ON/OFF) Ground balance: manual adjustment from 60 to 90 or automatic (fast grab). Salt mode ground rejection: 00-25 4 factory + 2 user programs. Target ID/ Iron probability. Pinpoint function with target zoom. Go-Terrain compatible (smartphone app coming soon). ads by Google... XP ORX MI-6 Compatibility Advanced remote settings when the ORX is paired with the MI-6 pinpointer: 50 levels of sensitivity Audio tone from 120 Hz to 1582 Hz 2 audio modes: PITCH or PULSE 3 factory + 1 user program Recover a lost MI-6 (even when switched off) Target zoom screen Battery life indicator I don't think there is much mystery here except for how many people will opt for this new model versus the new X35 coil based Deus models. In my opinion by extending the top end frequency of the new X35 coils to 28 khz has inadvertently removed some of the demand for this higher frequency version. Small gold sensitivity gains over 30 khz are quite minimal and with the extra features the Deus offers many people may continue to prefer it as their detecting solution. A lot may boil down to the price difference between a 9" round X35 Deus package and the 9" round HF Orx package. No matter what I am very confident this new high frequency XP model will do very well for gold prospecting. I do not expect performance to be any different than that I observed while testing the XP Deus with elliptical HF coil on small gold. XP Orx Data & Reviews XP Orx Owner's Manual Forum Threads Tagged "xp orx" XP Metal Detector Forum XP ORX Technical Specifications* Internet Price estimate $649 wired headphones or $795 wireless headphones Technology Induction Balance (IB) Frequency 14, 28, 56 kHz (round 9") or 14, 28, 70 kHz (elliptical) Autotune Mode(s) Multiple "Reactivity" Settings Ground Rejection Grab, Manual, Tracking Soil Adjust No Discrimination Variable, Visual ID, Tone ID, Notch Volume Control Yes Threshold Control Yes Tone Adjust Yes Audio Boost Yes Frequency Offset Yes Pinpoint Mode Yes Audio Output 1/8" headphone socket & speaker, wireless headphones Hip Mount Yes Standard Coil(s) 9" round DD or 9.5" elliptical DD Optional Search Coils new X35 coil series Battery Built In Rechargeable Operating Time 20 hours Weight 2.0 lbs Additional Technology Wireless coils, control box, headphones; firmware updates via internet Notes Probably based on "Africa Only" Depar DPR 600 *Notes on Technical Specifications - Detailed notes about the specifications listed in this chart.
  33. 1 point
    The Minelab GPZ 7000 was introduced in 2015 and is still in production. “This revolutionary new ZVT technology far surpasses GPX detectors for detecting deep large nuggets AND finding gold at any depth. The GPZ 7000 will open up the gold fields again.” -Bruce Candy, GPZ Inventor "I have been using the Minelab GPZ 7000 for some time, first as a tester prototype versions, and now as an owner of one of the first production line models. I did not find the GPZ 7000 to be a detector that immediately wowed me. Instead, it is a detector that reveals itself with use. However, I did finally have my Eureka Moment with the GPZ 7000 and after that there was no turning back. I sold my Minelab GPX 5000 and the large collection of accessory coils and other options I had accumulated for it. I am fully convinced that using the GPZ 7000 in the future gives me a better chance of finding gold, especially certain types of gold previously undetectable by other detectors." - Steve Herschbach The GPZ 7000 housing is obviously based on that used on the earlier Minelab CTX 3030 model. The battery is slightly larger and has twice the capacity of the battery on the CTX 3030. The batteries are compatible with each other (you can use the smaller CTX battery on the GPZ 7000) and use the same charger system. The Minelab GPZ features a simple LCD menu system with GPS locating and PC mapping options. One set of screen options controls the metal detector settings, while another set controls the integrated GPS tracking and mapping system. The GPZ 7000 is fully weatherproof and the GPZ 14 coil is fully waterproof to 1 meter. New coils, when purchased, will come with the short lower rod section attached plus an included scuff cover / skid plate. Currently the GPZ 7000 has only two coils available, the stock 14" x 13" GPZ 14 Super D coil, and the 19" x 18" GPZ 19 coil. Rumors persist of both a small coil in the works from Minelab, plus possible aftermarket coils. The coil that comes with the GPZ 7000 is remarkable however in the combination of sensitivity to small gold and depth on large gold that it covers. Minelab GPZ 7000 gold nugget detector with Zero Voltage Technology (ZVT) I am fortunate to have had the opportunity to field test the new Minelab GPZ 7000 detector. It allowed me time to make decisions regarding my own use of detectors earlier than most people. It also gave me a place first in line and I now have a brand new GPZ 7000 of my own. My use of the GPZ 7000 combined with what I think I know about how it works made me decide I had to have one. I am in my detecting prime right now and plan on spending a huge amount of time swinging a detector looking for gold now and in the future. I will never use just one detector for everything but the fact is that I can only swing one detector at a time. I need to decide what detector will be my primary unit for the bulk of my detecting. What one machine will best return my investment of time and effort in possible gold finds? I have decided that machine is the Minelab GPZ 7000. The GPZ with its 14" x 13" Super D coil provides an across the board powerful solution for getting gold both large and small on the first pass. Most ground I pass a coil over I have exactly one chance of finding a target. It has to happen on that first pass. Sure, when I am beating a patch to death I may hit the same area over and over. But most of my detecting is all about being over ground I have never been over before. I have to have confidence the machine I am using is going to give me my best shot at getting whatever is there on the first and likely last pass of the coil. As far as I am concerned all the percentages and charts and stuff is something others can debate, though I will post some thoughts on that separately. The bottom line is I am convinced the GPZ 7000 does give me a technological edge at this time, and that by applying that edge early and as often as I can I am increasing my odds of finding gold. If I never said another word about the detector that really just sums it up. I thought very hard about whether I should keep my GPX 5000. I decided any time spent with it would detract from the advantage I would enjoy by using the GPZ instead. It should not have been lost on people that I sold my GPX 5000 and almost every accessory I owned for it. That alone should tell you everything you need to know about what I think of the GPZ 7000. I even sold my SDC 2300. I was tempted to keep it until a smaller coil becomes available for the GPZ. Small coils are a must for nooks and crannies and other places larger coils can't fit. Yet as I considered it all I had to question just how much use the SDC 2300 would get if I had access to a GPZ 7000, and the answer was not very much. It found a new home. ads by Amazon... The GPZ 7000 does not replace or take away from the SDC 2300 and GPX 5000 in the current Minelab lineup. They are both fantastic units. The GPX 5000 and its vast ecosystem of coils and other accessories remains the no-brainer best value for many people. The SDC 2300 will continue to be the hot small gold sniper it has been proven to be. A person who owns both will have much of the power of the GPZ 7000 already at their disposal. The thing is the GPZ 7000 to the best of my determination so far seems to offer almost everything those two models offers in a single unit, and then goes farther yet. I can't swear that under every circumstance and in every scenario that the GPZ 7000 trumps the SDC 2300 or GPX 5000. Certainly in the case of the GPX 5000 all those accessory coil options do matter, especially where ground coverage is job one. The SDC does have that little coil. All I can say is that for that proverbial one pass over any particular chunk of ground I have to pick the GPZ 7000 as my best bet for getting whatever gold is there or missing it forever. And for hitting already hunted ground it is going to find gold both those detectors will miss no matter how many times they pass over the ground. The GPZ 7000 in my opinion is the best overall single solution available. If I was told I had to sell all but one machine and could only use one detector for gold prospecting I would without hesitation choose the GPZ 7000. In closing, I suddenly see a bright future ahead. I really had given up on there being anything significantly better than a GPX 5000. The GPZ however is not the end of the road but just the beginning. As good as it is it is not perfect and I am certain we will see further improvements as the platform is refined in the future. That first step is often the biggest and the GPZ in its way is every bit the breakthrough the SD 2000 was when it was released. Nobody can put back all the gold that has been detected in the twenty years since but the GPZ 7000 is definitely the next step in getting what is left. My thanks to Minelab for being able to say I had a part in this, small as it has been. Thanks especially for investing the huge amount of dollars and people power it took to make this happen for us, the prospectors of the world. Were it not for Minelab electronic prospecting would not be near what it is today. ~ Steve Herschbach Copyright © 2015 Herschbach Enterprises Official Minelab GPZ 7000 Page GPZ 7000 Instruction Manual Minelab GPZ 7000 Color Brochure Minelab GPZ 7000 Ferrite Field Guide GPZ 7000 Software Update Page Official GPZ 19 Accessory Coil Page GPZ 7000 Zero Voltage Transmission (ZVT) Explained GPZ 7000 Tips For Better Ground Balance GPZ 7000 In Difficult Ground Conditions Forum Threads Tagged "minelab gpz" Minelab Metal Detectors Forum Minelab GPZ 7000 Technical Specifications* Internet Price $7999 Technology ZVT - Zero Voltage Transmission Frequency N/A Autotune Mode(s) Preset Slow Motion Ground Rejection Automatic, Semi- Auto, and Fixed Soil Adjust Normal, Difficult, Severe Discrimination No Volume Control Yes Threshold Control Yes Tone Adjust Yes Audio Boost No Frequency Offset Yes Pinpoint Mode No Audio Output 1/4" Headphone Socket, Wireless Module With Speaker, Headphones supplied Hip Mount No Standard Coil(s) 14" x 13" GPZ 14 Super-D Optional Search Coils 19" x 18" GPZ 19 Battery Li-Ion Rechargeable Pack, 7.2V, 72Wh Operating Time 8+ Hours Weight 7.32 lbs. Additional Technology Integrated GPS With PC Mapping Interface Notes Weatherproof *Notes on Technical Specifications - Detailed notes about the specifications listed in this chart. Using the GPZ 7000 Part 1 by Nenad Lonic Using the GPZ 7000 Part 2 by Nenad Lonic Using the GPZ 7000 Part 3 by Nenad Lonic
  34. 1 point
    The Fisher F19 was introduced in 2014 and is still in production. It was originally released in two "Limited Edition" models that feature a camouflage paint scheme, one in green and one in pink. There are no other differences between the Ltd models and the standard black and gold model finally released in late 2015 except for a slightly lower price. The Fisher F19 is basically a Fisher Gold Bug Pro enhanced with additional features to make it more appealing as an all around detector. The F19 is mainly targeting the relic hunting market. The features revolve around enhancing the discrimination capabilities for working in sites with heavy ferrous trash. In particular, the ability to adjust the volume of the ferrous tones has been welcomed by many. A backlight has also been added for working in low light conditions. First Texas, the company that owns Fisher, also markets this detector under the Teknetics brand as the Teknetics G2+. The main difference is the Teknetics model uses the pistol grip rod and handle from the Teknetics T2 instead of the "S" rod utilized on the F19. Fisher F19 Black and gold variant with 6" x 10" DD coil The extra features do not really add to the ability of the F19 to perform as a nugget detector but neither do they detract from that capability, and some people may prefer this detector to the Gold Bug Pro due to the extra versatility. In particular those wishing to have the 5" x 10" DD coil as the primary and only coil for the detector will be interested because this currently is the only model in the series that comes with this coil as standard equipment.\I am a big fan of the Gold Bug Pro but if I was to buy another one new today I would personally be looking at the F19 or G2+. I may not have a pressing need for the extra features, but I would rather have options and not need them then find a time when I want the option and don't have it! These machines have been offered periodically at very steep discounts, and so with careful shopping you can get an F19 for not much more than a Gold Bug Pro, especially once you consider the coil options. Fisher F19 with 11" DD Coil Option and Teknetics G2+ variant Official Fisher F19 Page Fisher F19 User Review Page Fisher F19 Instruction Manual Difference Between Gold Bug, F19, and G2+ Forum Threads Tagged "fisher f19" First Texas (Fisher) Metal Detector Forum Fisher F19 Technical Specifications* Internet Price $449.00 Technology Induction Balance (IB) Transmit Frequency 19 kHz Autotune Mode(s) Pre-Set Slow Motion Ground Rejection Manual Touch Pads with Grab Function Soil Adjust No Discrimination One turn control, Visual ID, Tone ID, Notch Disc Volume Control Yes Threshold Control One turn control Tone Adjust No Audio Boost No Frequency Offset No Pinpoint Mode Yes Audio Output 1/4" headphone socket & speaker Hip Mount No Standard Coil(s) 5" x 10" DD or 7" x 11" DD Optional Search Coils Many accessory coils available Battery One 9V Operating Time 15 hours Weight 2.6 pounds Additional Technology Meter backlight, ferrous volume control, adjustable tone breakpoint between ferrous and non-ferrous Notes Available in green camo and pink camo or standard black & gold *Notes on Technical Specifications - Detailed notes about the specifications listed in this chart.
  35. 1 point
    Here is some state specific information to get you started on your search for gold and other valuable minerals. A lot of the basic information is drawn from Principal Gold-Producing Districts of the United States by A. H. Koschmann and M. H. Bergendahl, 1968 USGS Professional Paper 610 and then updated where possible. For a list of publicly available locations see Public Mining Sites, Parks, Tours and Other Attractions Most of the principal gold-producing districts are in the mountainous areas of the United States, where folding, faulting, and igneous intrusions have deformed the rocks. In contrast, many large base-metal deposits are found in the large relatively un-deformed areas of the Central and Eastern States, but gold is not even a byproduct of these ores. Large parts of the Western States, such as the Colorado Plateau, the Columbia Plateau, and much of Wyoming, have not been subjected to violent tectonic forces and consequently contain very few gold deposits. Most of the gold deposits in the United States are associated with and are perhaps genetically related to small batholiths, stocks, and satellitic intrusive bodies of quartz monzonitic composition that range in age from Jurassic to Tertiary. Some deposits, such as those in the Southeastern States, may be genetically related to granitic bodies that were intruded at the close of Paleozoic time, and a few deposits, as at Jerome, Ariz., are Precambrian in age. Alabama Gold was discovered in Alabama in the early 1830s. Recorded production to 1939 was about 49,000 troy ounces of gold; however, probably an equal amount has been mined but not reported. Gold has been produced from seven districts in the Alabama Piedmont Province. More than 100 prospects and mines are known in these seven districts. Gold mining ceased in Alabama, except on an individual basis, during the late 1930s. Exploration of gold deposits in Alabama has been carried out intermittently during the past several years in the historic gold districts. In 2008, gold prices exceeded $1,000 per troy ounce, increasing interest in the historic gold districts of the state. Minerals in the Economy of Alabama, 2007 Alaska Alaska has yielded over 40,416,575 ounces from the first discovery in 1848 through 2010. A large portion of this total was mined from placers in the Yukon region and the Seward Peninsula. The important lode-mining area in the past was Southeastern Alaska, where mines in the Juneau and Chichagof districts produced more than 7 million ounces of gold through 1959. More recently large lode mines in Interior Alaska such as Ft. Knox and Pogo have replaced Southeastern Alaska as the main sources of lode gold. Gold Prospecting Research Material for Alaska Arizona Arizona’s cumulative gold production exceeds 16 million ounces contributed from 219 metallic mineral districts. Twenty-six of those districts have produced more than 100,000 ounces and 46 have produced more than 10,000 ounces. Much of the past gold production has been a by-product of large scale copper mining. Arizona hosts a number of deposits with known potential to produce a few hundred thousand ounces or more. Arizona Gold Prospecting California California has produced more gold than any other State - more than 106 million ounces from 1848 through 1965. The well-known discovery in El Dorado County in 1848 sparked a series of gold rushes that indirectly led to colonization of the entire mountain West. The rich gold placers of California yielded phenomenal wealth in the early years, and as the placers were depleted, prospectors searched for and found the source of the placer gold - the high-grade gold-quartz veins of the Mother Lode and Grass Valley. Others explored the forbidding mountain ranges of southern California and found productive lodes in the Cove, Rand, and Stedman districts. Placer mining was rejuvenated in the early 1900's with the introduction of large bucket dredges. From the late 1930's onward, dredging operations were responsible for a major part of California's gold output. Prospecting Research Material for California Colorado Colorado ranks second among the gold-producing States; its gold output through 1965 was about 40,776,000 ounces. The first publicized discovery of gold in Colorado was in 1858. The immediate rush to the Denver area resulted in important placer finds near Idaho Springs and Central City. Prospectors ranging far up the Arkansas River valley found gold placers near Leadville as early as 1859. Many rich gold lodes were quickly discovered, and Colorado soon became a major mining area. In the 1870's, important ore discoveries were made in the San Juan Mountains, the Sawatch Mountains, and in the Leadville-Breckenridge area. Gold ore was found in the important Cripple Creek district in 1891. USGS Professional Paper 610 Georgia Georgia is credited with a total historical production of 871,000 ounces of gold from 1830 through 1959. Although a historically important gold producer, the state does not presently produce anything more than minor amounts of gold. Idaho Idaho, which ranks ninth among the gold-producing States, is credited with producing 8,323,000 ounces of gold from 1863 through 1965. The earliest recorded discovery in Idaho was of placer gold along the Pend Oreille River in 1852. Rich placers were found soon afterward at Pierce City, Elk City, Orofino, Boise Basin, Florence, and Warren, and a brief period of feverish activity followed. By 1870, many of the richer placers were exhausted, and an intensive search for lode deposits resulted. Large-scale dredging rejuvenated the placers, though after 1900, most of Idaho's gold was produced from lode mines. USGS Professional Paper 610 Maryland Placer gold was discovered at Great Falls in 1861. A number of mines were opened on gold-bearing quartz veins in Montgomery County. No gold production has been reported since 1951. Total production was about 6,000 ounces. Michigan In Michigan the only significant gold output has come from the Ropes mine in Marquette County near Ishpeming. Total production was about 29,000 ounces. USGS Professional Paper 610 Montana Montana, which yielded a total of 17,752,000 ounces of gold from 1862 through 1965, is seventh among the gold-producing States. Gold was first discovered in 1852 in placers in Powell County, but the influx of prospectors did not begin until the discovery of rich placers in the Bannack district in 1862. Numerous placers were found in rapid succession, among them those of Alder Gulch, which were to become the most productive placers in the State. Placers, which contributed almost half of Montana's total gold, had their greatest output before 1870; nevertheless, dredging and hydraulic placer mining were conducted on a large scale until World War II. Development of lodes, hindered by lack of railroads in the early days, progressed rapidly in the 1880's and was accelerated greatly with the expansion of operations at Butte in the early 1900's. USGS Professional Paper 610 Nevada Though Nevada is primarily a silver-mining State, it produced a total of about 27,475,000 ounces of gold from 1859 through 1965 and ranks fifth among the gold-producing States. Mining began in the early 1850's and the period 1859-79 was the boom era of the Comstock Lode and Reese River districts. After a period of decline from 1880 to 1900, the discoveries at Tonopah and Goldfield rejuvenated mining in the State until World War I. Lead, zinc, and copper mining, which yield gold as a byproduct, dominated Nevada's mining industry from the end of World War I through 1959, although for short periods large gold operations in the Potosi, Round Mountain, and Bullion districts have been significant. Discovery of the Carlin gold deposit in 1962 has revived interest in the gold potential of the State. USGS Professional Paper 610 New Mexico New Mexico produced about 2,267,000 ounces of gold from 1848 through 1965. Though gold lodes were worked on a small scale as early as 1833, prospectors showed little interest in the territory until the 1860's and 1870's. In rapid succession, lode and placer gold and rich silver and silver-lead discoveries were made, and mining flourished. By 1900, however, the oxidized ores were depleted, and interest turned to developing the primary base-metal ores from which gold is produced as a byproduct. This trend continued, in general, through 1959. The major gold districts are Elizabeth-town-Baldy, Mogollon, and Lordsburg. USGS Professional Paper 610 North Carolina North Carolina was the site of the first gold rush in the United States, following the discovery of a 17 pound gold nugget by 12-year old Conrad Reed in a creek at his father’s farm in 1799. North Carolina produced about 50,000 ounces of gold from lode and placer deposits. Oregon Oregon, the tenth most important gold-mining State, produced 5,797,000 ounces of gold from 1852 through 1965. Gold placers were worked as early as 1852, but the great rush to Oregon did not take place until 1861, after the placer discovery at Griffin Gulch in Baker County. After an initial period of high placer output, gold lodes were found and developed at a less frenzied rate. By the early 1900's, gold mining began a decline that lasted until 1934 when it was rejuvenated by the increase in the price of gold. A few districts, notably the Sumpter, were then reactivated, and gold mining was revived through the late 1930's and early 1940's until the demands of World War II diverted mining to commodities other than gold. Gold mining in Oregon in the post-World War II period has been in a steady decline. USGS Professional Paper 610 Pennsylvania Most of Pennsylvania's gold has been produced from the Cornwall iron mine in Lebanon County.* Where to Find Gold in Pennsylvania and Gold in Pennsylvania. USGS Professional Paper 610 South Carolina Total gold production of South Carolina through 1959 was 318,801 ounces. High gold prices are leading to increased interest in South Carolina gold. Gold mining may commence soon at the historic Haile mine. South Dakota South Dakota, third among the gold-producing States, produced a total of about 31,208,000 ounces of gold through 1965, mostly from the Homestake mine. The gold districts are in the Black Hills in the northwestern part of the State. Most gold has been produced from lode deposits, but placers have also been mined. USGS Professional Paper 610 Tennessee Gold in Tennessee is a byproduct of the copper ores of the Ducktown district in Polk County; small amounts have been mined from placers on Coker Creek in Monroe County. Both areas are in the southeastern part of the State. Total production is over 14,000 ounces. USGS Professional Paper 610 Utah Utah, whose total gold output through 1965 was 17,765,000 ounces, ranks sixth among the gold-producing States. The first major ore discovery in the State was in 1863, when lead ore was found in Bingham Canyon. Gold placers were found nearby the following year. Silver-lead ore discoveries in the Cottonwood, Park City, and Tintic districts in the late 1860's and 1870's generated feverish activity which lasted until 1893 when the financial recession caused a sharp drop in the price of silver. In the early 1900's, large-scale mining of the low-grade copper ores of the Bingham district began. Gold has been an important byproduct of these ores. In 1965, the Bingham district, in addition to being one of the major copper producers of the world, was the second largest gold producer in the United States. The Tintic, Park City, and Camp Floyd districts also have yielded substantial amounts of gold. USGS Professional Paper 610 Virginia About 100,000 troy ounces of gold were produced in Virginia from 1804 through 1947, when gold was last produced in the State. Gold in Virginia, 2007 Washington Washington, whose total gold output from 1860 through 1965 was about 3,671,000 ounces, is one of the few States in which gold production has increased in recent years, mainly because of the output of the Knob Hill mine in the Republic district and the Gold King mine in the Wenatchee district. Gold was first discovered in the State in 1853 in the Yakima River valley. Placers were worked along most of the major streams of the State through the 1880's, but most of them were depleted by the early 1900's. Lode deposits were found in the 1870's and eventually supplanted placers as the chief source of gold. Of the 15 major gold districts of Washington, the most productive have been Republic, Wenatchee, and Chelan Lake. USGS Professional Paper 610 Wyoming Wyoming is a minor gold-producing State; its total output through 1965 was over 180,000 ounces. Only two districts - the Douglas Creek and the Atlantic City-South Pass - have been significant. USGS Professional Paper 610 Australia Nobody knows what the production figures are but there is little doubt hundreds of thousands of ounces of gold have been found in Australia by prospectors with metal detectors in the last 40 years. Gold in Australia
  36. 1 point
    A select list of online resources that will aid any prospector looking for gold or other valuable minerals in Alaska. Alaska Mining Information Portal This is your place to start for mining claim information, rules, regulations, and permits. Alaska's Mineral Industry Reports Yearly snapshots of Alaska's mineral industry, full of clues as to where the action is throughout the state. Placer Deposits of Alaska by Edward H. Cobb 1973 USGS Bulletin 1374. An inventory of the placer mines and prospects of Alaska, their history and geologic setting. Metalliferous Lode Deposits of Alaska by Henry C. Berg and Edward H. Cobb 1967 USGS Bulletin 1246. An inventory of the lode mines and prospects of Alaska and their geologic settings. Significant Metalliferous Lode Deposits and Placer Districts of Alaska by Warren J. Nokleberg, Thomas K. Bundtzen, Henry C. Berg, David A. Brew, Donald Grybeck, Mark S. Robinson, Thomas E. Smith, and Warren Yeend 1987 USGS Bulletin 1786. This report is a compilation of the significant metalliferous lode deposits and placer districts of Alaska. Mineral Resources of Northern Alaska by the Mineral Industry Research Laboratory edited by Lawrence E. Heiner and Ernest N. Wolff 1969 M.I.R.L. Report No. 16. This is the final report on the work authorized on July 29, 1967, by the NORTH Commission. The purpose is to inventory mineral resources in northern Alaska and to delineate favorable mineral areas, insofar as possible. Placer gold sampling in and near the Chugach National Forest, Alaska by R. B. Hoekzema and S.A. Fechner 1986 U.S. Bureau of Mines Information Circular 9091. This report summarizes the Bureau's placer gold studies in the Chugach National Forest. Evaluation of selected lode gold deposits in the Chugach National Forest, Alaska by R. B. Hoekzema, S. A. Fechner, and J. M. Kurtak 1986 U.S. Bureau of Mines Information Circular 9113. This Bureau of Mines report describes the history, characteristics, distribution, and mineral development potential of 21 lode gold deposits in or near the Chugach National Forest. Gold Placers of the Historical Fortymile River Region, Alaska by Warren Yeend 1996 USGS Bulletin 2125. The Fortymile River region in east-central Alaska has a long and colorful history as the site of the first major gold discovery in interior Alaska. Alaska Resource Data File Descriptions of mines, prospects, and mineral occurrences in the Alaska Resource Data File (ARDF) are published for individual U.S. Geological Survey 1:250,000 scale quadrangles in Alaska. These descriptions were compiled from published literature and from unpublished reports and data from industry, the U.S. Bureau of Mines, and the U.S. Geological Survey and other sources. The database contains 7,288 records. Fineness of Gold from Alaska Placers by Philip S. Smith 1937 USGS Bulletin 910-C. Alaska placer gold ranges from more than 970 fine to slightly less than 565 fine. A Summary of Gold Fineness Values from Alaska Placer Deposits by Paul A. Metz and D.B. Hawkins 1981 Mineral Industry Research Laboratory. Gold fineness values for Alaskan placer deposits were calculated using mint return production records. BLM Alaska Mining and Minerals Federal Mining Claims Information For Alaska Updated 2015 Placer Mining Claim Owner's Guide For Validity Exams On BLM Managed Lands In Alaska Updated 2014 Alaska Resources Library and Information Services (ARLIS) Generally Allowed Uses on State Land State of Alaska Mining and Land Factsheets Alaska Mining Laws & Regulations Booklet Updated 2014 Fine Gold Recovery of Selected Sluicebox Configurations by University of British Columbia, G. W. Poling & J. F. Hamilton The Use of Radiotracers to Evaluate Gold Losses at Klondike Placer Mines by Randy Clarkson/NEW ERA Engineering Corporation February 1990 Placer Gold Recovery Research - Final Summary by Randy Clarkson/NEW ERA Engineering Corporation December 1990 Placer Examination Principles and Practice by John H. Wells 1969 BLM Technical Bulletin 4
  37. 1 point
    These are "how to" guides on metal detecting and gold prospecting themes written by Steve Herschbach. Each article focuses on a single subject and they are meant to be relatively short but cover the topic well. Information both for beginners plus advanced topics for the pros. Metal Detecting Steve's Guide to Headphones for Metal Detecting Steve’s Guide to Metal Detecting for Gold Nuggets Steve's Guide to Gold Nugget Detectors Steve's Guide to Beach Detecting For Gold Prospectors Steve's Guide to Gold Nugget Target ID Numbers Steve's Guide to Metal Detector Search Coil Compatibility Steve's Guide to Threshold Autotune, SAT & V/SAT Steve's Guide to Metal Detector Mixed Modes Steve's Guide to Multifrequency Metal Detectors Steve's Guide to Waterproof VLF Metal Detectors Steve's Guide to Differences Between Minelab SD, GP, & GPX Steve's Guide to Minelab GPX Timings Steve's Guide to White's Electronics GMT versus MXT Steve's Guide to White's TDI Coin Settings Steve's Guide to Rebuilding The White's GMT White's MXT Engineering Guide Metal Detector Database with User Reviews Prospecting Steve's Guide to How to Pan for Gold Steve's Guide to Suction Gold Dredges Steve's Guide to Where To Prospect For Gold Gold Prospecting Research Material For Alaska General Other Metal Detecting & Prospecting Websites Steve's Guide to Successful Rock Tumbling Metal Detecting & Prospecting Library Catalogs, Brochures, User Guides, & Owner's Manuals
  38. 1 point
    The two best-selling professional metal detectors in Alaska over the last twenty years are probably the White’s Electronics GMT and White’s Electronics MXT. This is because a set of local circumstances favored these two detectors. These two machines are based on the same circuitry, but have very different design goals and therefore features which determine which might be the best choice. Since the sole purpose of the GMT is prospecting, it operates at a high 48 kHz for extreme sensitivity to small metal items... hopefully gold nuggets. It is not a "gold-only" machine in that it picks up all metals. The "gold-only" detector has yet to be invented. It does however have a very efficient system for separating ferrous (iron or steel) items from non-ferrous items (gold, copper, silver, lead, aluminum, etc.) In theory the GMT could be used for other types of detecting, but it has a couple serious problems. First is the fact that it is so sensitive to small metal! Any attempt to use it for typical coin detecting would leave a detectorist quickly frustrated. Imagine a foil gum wrapper sucked into a lawn mower, shredded, and spread about. Parks and other areas popular with coin hunters are full of tiny aluminum trash. Every one of these items will sing out loudly on the GMT. Coin detectors are purposely designed not to pick up these tiny non-ferrous items as 99% of the time they are trash. The GMT also is very sensitive to wet salt sand, and so is useless for most beach detecting. It would not be impossible to use the GMT for other detecting tasks, but in general it really should not be considered for anything other than nugget detecting. The MXT was built using the GMT circuitry. An advanced LCD readout discrimination system similar to that on top-of-the-line coin detectors was added. The frequency was lowered to 14.7 kHz to increase the sensitivity to coin type targets and to moderate the problem of being too sensitive to tiny trash. But the frequency is still well above that of standard coin detectors which work around 6 kHz so the MXT retains much of the GMT ability to hit gold targets. The MXT has three distinct modes: Coin & Jewelry, Relic, and Prospecting. Each mode dramatically changes both the sounds and the LCD readouts generated by different targets. The Coin & Jewelry mode is very much like any standard coin detector, but with a better than normal sensitivity to gold coins and gold jewelry. The Relic mode is a rather unique dual tone mode that operates in both all-metal and discriminate modes at the same time. That alone is subject for another article! The Prospecting mode in effect turns the detector into a GMT, but one that runs at a lower frequency and that lacks a manual ground balance. And the MXT has a special Salt setting to allow it to work on those beaches. White's GMT versus White's MXT The GMT is admittedly superior when it comes to picking up small gold. It can hit specks weighing less than 1/10th of a grain (480 grains per Troy ounce) while the MXT will need nuggets weighing 2-3 grains to get a decent signal. But on the flip side, the MXT may very well be the superior unit for large nugget detecting. The lower frequency actually is smoother in mineralized ground, and in particular does not produce as many weak variations in the threshold in mixed cobbles as the GMT. The drawback of higher frequencies is that while small gold produces a sharper response, so do hot rocks. The manual ground balance on the GMT is very helpful for hitting those tiniest specks, but less useful for larger gold. If larger gold nuggets are the goal, then the MXT is every bit equal, if not better than the GMT in overall performance. For Alaska those wanting to go places like Crow Creek or Mills Creek and have a chance of getting gold, any gold at all, will be best served by the GMT, especially if paired with the little 4” x 6” Shooter coil. It will get the gold in these heavily hunted areas, and will hit gold the MXT will miss. But if versatility is important, or chasing large gold nuggets in tailing piles at Ganes Creek is the goal, the MXT is the way to go in my opinion. It is simply one of the best all-around detectors I have ever used. The White’s MXT Engineering Guide is full of interesting information on the development of the GMT and MXT and provides a rare look at what goes on behind the scenes at a metal detector company. ~ Steve Herschbach Copyright © 2010 Herschbach Enterprises
  39. 1 point
    I thought I'd point out a link to the Minelab GP 3500 review I wrote for the September issue of Lost Treasure magazine. They have it on their website (edit Dec 2018 - Lost Treasure magazine is out of business and link is gone) for those of you that may have missed it. One thing I made a point of doing in the article is trying to get people to consider the Minelab GP 3500 as much more than just a "nugget detector". The fact is that it is one of the most powerful metal detectors available today, and can hit coins, jewelry, relics, and yes, nuggets, deeper than most metal detectors. Since it is a pulse induction (PI) detector, it has a relatively limited ability to discriminate targets. That said, by learning the tones the machine puts out and using the iron discrimination circuit you get more ability to read targets than is the case with most PI detectors. I've been experimenting with my GP 3500 as a coin and jewelry detector. The short story is it easily hits targets deeper than the best VLF detectors. Yes, you dig more junk, but the biggest limiting factor may be that the unit is TOO powerful. You can only dig holes so deep in public places, and so many parks and other groomed areas are in effect off-limits to the GP 3500 as digging holes over a foot deep in not an option in many parks. But for beach use and relic or coin detecting in areas where digging extra deep is allowable, the GP 3500 is certain to pull up finds people with VLF machines are leaving behind. The GP 3500 control box is protected with a Coiltek neoprene cover. I have a half-size Minelab battery tied to the side of the unit in its own Minelab battery belt pouch. Another option are the new Pocket Rocket Lithium Ion batteries. The battery is connected to the control box with a Coiltek short power cable, the one Coiltek sells for use as a charging cable instead of using the 3 foot Minelab cable. 6.8 pennyweight gold nugget found with Minelab GP 3500 This setup allows me to set the detector down and dig without being attached to the machine by a normal backpack mounted battery and cable setup. The half-size battery is fine for more hours of coin detecting than I'd normally ever undertake in a day. And the whole setup is not so heavy that I cannot handle it for long hours. I plan to use it for nugget detecting in brushy areas next summer or for some "dig and detect" sessions where the machine spends more time on the ground than on my arm. I'm using the Coiltek 14" mono coil which seems to work well for the coin detecting. The stock 11" coil is ok but is a bit too sensitive to tiny surface trash the larger coil tends to ignore. Being a mono coil the 14" has terrific depth for its size, but I have given up the ability to use the GP iron discrimination circuit. I'm going by the tones only (the review describes this in detail), but I'm looking at a mid-sized DD coil for this use to get back that extra discrimination ability. This would help eliminate a few of the iron targets I'm currently digging. The headphones are the DetectorPro Uniprobe combination headphone/PI pinpointer setup that is a must for this type of detecting. The Uniprobe pinpointers are easily the most powerful I have used, in that they are a full-fledged pulse induction metal detector with a probe attached instead of a coil. In fact, there is an optional 11" coil and handle assembly available to convert the Uniprobe into a great little PI detector. Normally with a GP 3500 you just dig a huge hole while nugget detecting. But for coin and jewelry detecting better pinpointing skills must be developed, and the use of a good pinpointer is a real requirement. I highly recommend the Uniprobe pinpointers. The headphone model is mounted in a set of Gray Ghost headphones, which works great for me as I am a headphone addict. DetectorPro makes a Pocket Uniprobe that has a speaker but I cannot hear it very well with headphones on. Plus, it is just another gadget to carry. I tried the Pocket Uniprobe and decided having it all in one unit works better for me. Minelab GP 3500 rigged up to hunt without using harness and bungee setup The final item in the picture is my digging pick. I do not like the short handles that are standard on most picks. I got a 36" hickory sledge hammer handle and replaced the stock handle, although I can switch it back as both handles mount with a single bolt to the head. I like these long-handle picks as I use them as a walking stick (great for side-hilling at Moore Creek!), and I have to bend over less when I dig. There is, of course, a super magnet attached to the head of the pick for sucking up small iron trash. The only other items I am using that are not in the picture are my nylon belt and large trash/treasure pouch and plastic scoop. The scoop is great for getting deeper into the bottom of the holes I dig, and for locating some small items as would be done in nugget detecting. All trash goes in the pouch for later disposal. I know these detectors are expensive, but if you have a serious need to get some REAL extra depth, you need to look hard at the Minelab GP 3500. These things would be awesome for hunting Civil War relics in a "worked out" location. Goose lake, Alaska plus gold nugget and old coins found with GP 3500 Two last hints. Carry a VLF detector along, and check the targets the GP 3500 finds for you. In some cases the target will be shallow enough you can save a little digging. But better yet, if you get no signal at all from your VLF unit, you'll know you have a deep target. You will be surprised how many of these there are that a VLF unit just will not hit. I afraid once you experience this for awhile you will tend to lose a certain amount of faith in your VLF detector. Yes, you are missing targets. LOTS of them. But the second hint is the best. Take the GP 3500 to a once good place, but one that has been hunted so much that there are no targets left using a VLF detector. I am sure that you will end up like me, simply amazed at how all of the sudden the place seems like it has never had a detector over it, there are so many targets. Better yet, all the shallow stuff should be gone, with only the deepest finds, and therefore some of the best, remaining for you! ~ Steve Herschbach Copyright © 2005 Herschbach Enterprises
  40. 1 point
    Doug Clark of Clark-Wiltz Mining opened the Ganes Creek property near McGrath, Alaska to recreational miners in 2002. The pay-to-mine operation ended in 2012. This page is being left up for historical purposes. Ganes Creek is famous for the large nuggets found there in years past, and it was conjectured that people would pay for an opportunity to search for large nuggets lost in the tailing piles by past mining operations. The operation was a resounding success and was in operation for a decade. Visitors in that time have found over 1700 ounce of gold and added a great deal of revenue to the mine above and beyond the mining operations. Approximately 12 people per week were allowed to visit Ganes Creek at a cost of $3000.00 per person. They got room and board and access to the old mining operations. Why they pay to visit Ganes Creek - 33.85 oz Nugget found by a visitor! 33.85 Ounce "Heart of Gold" Found June 16, 2004 at Ganes Creek near McGrath, Alaska by Steve Burris of Idaho with a Fisher Gold Bug 2. The nugget was found in an area where many others had detected, but all the previous detectorists had missed the nugget. Transportation to the mine was not included. The majority of visitors came from the Lower 48, with airline tickets running anywhere from $600.00 to $800.00 per person. Nearly all the visitors flew from Anchorage to McGrath via Peninsula Air at a round trip cost of about $420.00. The next leg of the journey is from McGrath to Ganes Creek via Tanana Air of McGrath at a cost of approximately $200.00 per person. I was fortunate to have been at Ganes Creek many times over the years. You can tag along on some of those visits by looking over the Ganes Creek articles at Steve's Mining Journal. Here is just one story to get you started - Memorial Day at Ganes Creek, Alaska - 5/25/02 Steve Herschbach shows off gold found at Ganes Creek over Memorial Day weekend 2002
  41. 1 point
    Bertha Creek Gold Panning Area An early prospector named Bertha Creek after his daughter. Hand placer and hydraulic mining began in 1902 and may have yielded up to 600 troy ounces of gold. Most gold came from the alluvial fan below the canyon. Bertha Creek crosses the Seward Highway 2.6 miles south of Turnagain Pass. Lower Bertha Creek lies within a withdrawal that extends for 1,300 feet on either side of the Seward Highway from Turnagain Pass south to Pete’s Creek. Bertha Creek is available for recreational panning from its junction with Granite Creek upstream to the powerline crossing (Map). Granite Creek, however, is closed to recreational mining because of its salmon spawning habitat. Bertha Creek south of Anchorage on the Kenai Peninsula Bertha Creek’s upper portion flows through a glacier-carved valley. Slate bedrock is exposed for 850 feet along the creek, beginning 150 feet above the Seward Highway’s Bertha Creek bridge. A rough trail leads up the east side of the creek. The tan-colored clay layer on bedrock is a good bet for gold that ranges from flaky to nuggety. Single pans have produced gold pieces up to 1/4 inch long. The rust-colored quartz float in the stream bed occasionally contains pyrite cubes and may be the placer gold source. Another trail leaves the highway 250 feet north of the bridge, leading up the northwest side of the creek. At mile 0.2, it passes a bluff overlooking the site where Bertha Creek exits from a narrow steep walled canyon. You can get good colors from stream gravel and fractured bedrock in this area. You can also get gold from nearby Spokane Creek (Map) and Lyon, and Tincan creeks north of Bertha Creek. The withdrawal includes the lower creek portions that are open to recreational panning. An informal pull-off where the Seward Highway crosses Spokane Creek provides parking for 1-2 vehicles. Access Lyon and Tincan creeks from the Turnagain Pass rest area. Parking, camping, and picnic sites are available at Bertha Creek Campground. No motorized vehicles off established roadways in this area. Bertha Creek Public Mining Site Here are a few simple rules and guidelines that all recreational gold panners must know: Recreational gold panning on the Chugach National Forest consists of the use of hand tools, panning, sluicing, and suction dredging with a 4-inch or smaller intake hose. You must follow all National Forest rules, such as camping limits, discharge of firearms, and use of trails. You can find regulations in Title 36 Code of Federal Regulations (CFR), with general prohibitions in part 261. Review these regulations before you go gold panning. You can find copies of these regulations on the Internet and at Chugach National Forest offices in Anchorage, Girdwood, Seward, and Moose Pass. You can use gold pans and hand tools-fed sluice boxes year round in the streams listed in this booklet. No hydraulic mining or use of earth-moving equipment is allowed. Work only the active stream channel or unvegetated gravel bars. Do not dig in stream banks! You are not allowed to build structures, cut trees or dig up archaeological, historical, or paleontological objects, nor are you allowed to obstruct others in their recreational pursuits. If you find those objects, please report them to the Chugach National Forest. Suction dredges (4-inch nozzles or smaller) are permitted from May 15 to July 15 only. Remember that permits are required. The Kenai Peninsula is home to brown and black bears. Stay alert and avoid bears whenever possible. For more information, get Bear Facts from the U.S. Forest Service or Alaska Public Lands Information Centers. The water is cold and you can expect to get wet— after all, the gold is in the water. Wear insulated waterproof boots and gloves. Wool clothing can keep you warm even when wet. Bring extra clothing and dress in layers. Keep Alaska green, do not trash or litter. Many places have a $1,000 fine for littering. Follow Leave No Trace principles. Good luck and good prospecting! Bertha Creek, Alaska in 2014 Most of the information above was derived from GOLD PANNING, Guide to Recreational Gold Panning on the Kenai Peninsula, Chugach National Forest, Alaska (2018) found here - See the full text for more information and details.
  42. 1 point
    I finally went out and found my first gold nuggets with the new DEUS elliptical high frequency coil. I want to emphasize that I am a newbie on the XP Deus. Although I purchased an 11" Deus V3.2 model almost two years ago, it was with the express purpose of being able to test the V4 update with the new high frequency coil options for gold prospecting. I decided I was better off just starting fresh with version 4.0 before really digging in and learning the detector. I do get the hang of detectors quickly but this does show what can be done by somebody who went out barely knowing the machine. The other catch is that I picked a location that favors the Deus with relatively mild soil for a gold location, so mild I could run the machine full out to get the maximum possible sensitivity with the machine. These results are not going to be as easy to obtain in extreme mineral ground. You have to start someplace however and being new to the machine I wanted to give myself someplace easy to start. Finally, the goal here was to find the smallest gold I could so for the purposes of this report - smaller is better. These nuggets were recovered over the course of a day. Ten nuggets, 4.7 grains total weight. There are 480 grains per Troy ounce and with an average weight of less than half a grain I think you can agree this is some pretty small stuff. The smallest bits are probably near 1/10th grain or 1/4800th of a Troy ounce. Click picture for larger version. Ten nuggets, 4.7 grains total weight, found by Steve with Deus HF elliptical coil The new HF elliptical coil running at 74 kHz is clearly in the same league as the 71 kHz Fisher Gold Bug 2, 45 kHz Minelab Gold Monster, 56 kHz Makro Gold Racer, and 48 kHz White's GMT. However, the devil is in the details and it will be some time before I sort out how the machines compare under more difficult and varied conditions. Again, I am not an expert with the Deus and so the settings I mention are not to be taken as "the best" or anything like that. I was actually gold prospecting so the primary focus was to find gold, not to test every possible combination of settings on the Deus. With 10 program options and numerous settings that will be a longer term project. I obviously wanted to try the Gold Field program 10. After a little experimenting I settled on the GM Power program 2 as an alternate disc mode to try. Getting from program 10 to program 2 is only a couple button pushes, so I bounced back and forth between the two programs and tweaked settings higher as I found targets and could compare readings. Gold Field is a threshold based all metal mode with what I find to be a rather pleasant digitized buzz. That's me of course, others may differ on that point. I was able to run sensitivity full out at 99. All my work was done at 74 khz, the default highest frequency setting without trying to push it higher via the offset. I figure the coil is tuned at 74 khz and so stuck with that for now. Manual ground balance about 84. GM Power I got sensitivity to 94 with only minor falsing. I reduced reactivity (similar to SAT for you nugget hunters) to 0 from the default of 2 and ran the audio response (audio boost) up to 7 (max). Both modes exhibit just a little touch sensitivity at these high gain levels. This might be tamed with the ground notch but I have not fooled with that yet and it did not bother me at all anyway. What I found was Gold Field has a softer response in general but that my boosted version of GM Power banged hard on the little bits. Not unlike going from all metal mode on the Gold Bug 2 to the Iron Disc mode. Instead of faint threshold variations you get a strong "beep". The difference is that the Gold Bug 2 Iron Disc mode has an obvious loss in sensitivity. The Deus by comparison in this particular situation actually seemed to work better in GM Power mode, but that is mainly the boosted audio at work. I left the disc settings at the defaults for GM Power which worked well - low tone iron, higher tones non-ferrous. I ran the IAR (iron reject) in Gold Field at 2. This was just enough to cause ferrous to break up. Higher settings would blank most ferrous completely but getting to aggressive can also eliminate weak gold signals. The ferrous discrimination worked very well in both programs. GM Power in particular was pretty awesome in the nail pits with iron tones firing off like a machine gun. I bumped reactivity back to 2 in the dense trash. Anyway, this is a very preliminary report and so no point getting too deep into it as I will probably modify my opinions and settings as I get more time on the machine. Right now this is a high price option if all you need is a prospecting unit, but for a person wanting one machine to do everything XP just kicked it up a notch. If they introduce a dedicated gold unit at a lower price similar to the Depar DPR 600 it would be very competitive. For now this is an option for somebody that wants a detector for more than just gold prospecting since the Deus is a superb coin, relic, and jewelry detector. Steve's XP Deus with HF elliptical coil - it collapses to fit in that rucksack! The elliptical coil and rod assembly is just 1 lb 13 oz (1.8 lbs) and so a true featherweight. At 5' 11" I have to run it fully extended and at that it does flex a bit, but I did not find that bothersome at all. A solid coil cover will be good as there are too many coil edges that want to hang up on rubble and sticks. A minor quibble however as the machine is a joy to handle, especially when reaching uphill waist high and higher. A great unit for poking in and around bushes and other obstructions. The coil is hotter at the tips which also helps in poking into tight locations. Early days but the final word is that I am happy with how this coil performs on small gold nuggets after all the wait. Time will tell how it handles the really bad ground and how it fares directly against some of the competition as other people report in. As always giving it time and waiting for a consensus opinion from many users to develop is a wise policy with any new detector. This article originated as a post on the DetectorProspector Forum. There might be additional information there in follow up posts. ~ Steve Herschbach Copyright © 2017 Herschbach Enterprises
  43. 1 point
    Many people have seen the ad copy in the Minelab GPZ 7000 brochure where I am quoted about how amazing the new GPZ 7000 is. Now you get to hear the rest of the story. This is a more detailed version of an email I sent to Minelab last fall regarding the new GPZ 7000. The background is I had been using the GPZ prototype for some time but was underwhelmed. I was initially put off by the weight and frankly it was just not my trusty old GPX 5000 and I was slow to shift gears. Yes, the machine performed but I had not seen anything that particularly knocked my socks off and had not been shy in saying so to Minelab. I had an opportunity to return to a location in northern Nevada I had hunted gold previously in 2013. On that visit a portion of hillside was pointed out as the location of several nice nugget finds, including some delicate specimen gold. I did what any prospector would do and concentrated on hunting this area hard with my GPX 5000. I knew I was dealing with an area hunted hard with previous Minelab PI detectors and hot VLF detectors like the Fisher Gold Bug 2. I was the first there with a GPX 5000 however so figured I was going to find something others had missed. I was running a 14” x 9” Nugget Finder mono and set it up in Sharp at Gain of 16 which is a reasonably hot setting. I was disappointed to find nothing but bullets, and so I switched to a used White’s GMT I had just acquired. This high frequency VLF detector was able to find two small and very porous gold specimens. Having found these, I again scoured the area but there appeared to be nothing else to find. I was not the only person to detect this location of course and so I just figured it was pretty well detected out. Delicate Nevada gold specimen found by Steve with White's GMT The Minelab SDC 2300 came out in 2014 and Chris Ralph and I both had units which we were using with great success on gold the GPX was weak on. Small, porous, prickly gold. An invite came to visit the property again in the fall of 2014 and Chris and I figured the SDC would be just the thing to succeed where the GPX had failed. We were field testing the GPZ 7000 prototype also by this time. Chris was tied up but I had a chance to leave earlier and camped out a couple days in Humboldt County hunting with the GPZ. I was really pleased finding just shy of a half ounce (15.5 grams) of nice gold, including a solid 6 pennyweight (9.4 gram) nugget which was my largest with the GPZ to date. I was now starting to warm to the machine which seemed particularly well suited to the wide open spaces of northern Nevada. 15.5 grams of Nevada gold found by Steve with GPZ 7000 prototype - largest 9 grams The GPZ was of course a super secret project at that point, and so when I met Chris at the miner’s claims I had it carefully stowed away and pretty much forgot about it. The plan was to hunt with the SDC detectors. I pointed out the location where I had hunted with the GPX and GMT to Chris Ralph so he could give it a go with the SDC. Frankly, I did not think he would find a lot but the new SDC 2300 certainly had a chance of making some finds there. I hunted another hot spot nearby, and my own SDC 2300 found four or five nice little specimen pieces. I was really pleased when Chris showed up and showed me two fat specimen pieces, weighing about one quarter ounce in total. Everyone was very impressed with the SDC 2300 and the gold it was finding in areas hunted over and over with PI detectors and hot VLF detectors like the Fisher Gold Bug 2. The Minelab GPZ 7000 brochure quote by Steve We stayed the night but Chris had to leave the next day and it was good he went home with gold in his pocket. One of the claim owners also left, and it was down to just me and one claim partner. I stayed and hunted, finding another small specimen with the SDC 2300. I went a couple hours with no finds, and decided to wander over to the area where Chris had scored to see if I could do anything there. The claim owner and I puttered around awhile there then he decided it was time to go back to camp and grab some lunch. I was about to get going again with the SDC 2300 when I realized I had the new GPZ prototype still in my truck. The claim owner was over the hill out if sight, and since he had just left me I figured it was pretty safe to get GPZ out and give it a quick go. So I went back to my truck, switched out detectors, and headed to where Chris had marked his gold finds. Chris had hunted right where I had found the two specimens the year before with the GMT. I was a bit surprised I had missed two nearly 1/8th oz pieces but they were deeper than the GMT was going or I had written them off as ground noise. His two specimens were found only ten feet apart, and I could tell he had hammered the location. Every square inch of the dusty ground was covered with footprints. I fired up the GPZ and gave it a few swings, and was surprised to almost immediately get a nice signal exactly between the two little rock piles marking his find locations. I gave a few digs and revealed a nice specimen weighing about 3 grams! I know I had been over this location with a GPX 5000 and a GMT. Chris is very methodical when on a patch, and I know the SDC 2300 is more capable than the GPX 5000 when it comes to small specimen gold. How could this be? I suddenly realized I had something very special indeed in my hands. I wandered down slope, and right at the bottom of the hill where it started to flatten out I got another signal, and another couple gram specimen. Then only about 20 feet away I got another one. Now I was really getting excited. Less than ten feet away I got a real boomer signal, but it proved to be a bullet. Then a few feet, and another large signal. I dug deep into the hardpan, and know at that point it has to be gold. I dug carefully so as not to damage it, and finally recovered a solid lump quite a few inches down. It was an 11.2 gram or just over one third ounce gold specimen! Gold specimens fresh out of the ground perched on GPZ 7000 The property owners were very gracious and had told Chris and I we could keep all the gold we found. I appreciated that, but I also know that is easy to say when you do not think people will find very much, and the owners thought the ground pretty well detected. I was thinking at that point I needed to give them a share of the gold, but truthfully I did not want to part with this big lump, so I told myself I needed to find more gold. The problem was time was running out and I was worried the claim owner might come looking for me soon and see me with the GPZ. So I started scanning with 7000 as fast as if I was in a VLF competition hunt. My goal now was to just cover as much of this area as I could in a short amount of time. Apparently speed does not hurt the GPZ all that much, because in short order I found another couple gram specimen. More frantic scanning, and another nice piece popped out of the ground. This was crazy – I know I had hunted this area! I expanded the area of the hunt, but the gold seemed to be on a very tight line heading down the slope. Some time passed, and another two or three gram specimen saw the light of day. Now I was getting really worried the claim owner would show up and see me with the GPZ. I had a pouch full of gold specimens, and was really amped up at that point. I had not found that many large chunks of gold that fast in very many years. To say I was stunned would be an understatement. I had to quit though, and so I hunted up the slope so I could go back and show the claim owner my finds, and bring him back to hunt some more. I just figured I would put the GPZ away and go back to using the SDC 2300. I made a bee line up the hill to where my truck was parked, swinging all the way, when I got another good signal. I dug and it got louder. And louder. I was into the hard material now and knew it had to be gold, so I slowed up and worked the edges of the hole carefully. The last thing I wanted to do was ruin a nice specimen. Finally, about a foot down I grabbed a handful of loosened soil that screamed when I waved it over the coil, and I felt a lump drop into my other hand when I went to separate it. This one was at least twice as large as the big one I found earlier!! 0.79 ounce gold specimen just rinsed, found by Steve with Minelab GPZ 7000 I was having a Eureka Moment. This whole experience was mind blowing. I was finding gold right and left as if this location had never seen a detector before. The GPZ 7000 was working some serious electronic magic, and it seemed it was particularly effective on porous specimen gold at depth that other detectors have a hard time seeing. The GPZ 7000 was hitting this stuff not with weak but with strong signals, like the SDC but with a coil size much larger than that on the SDC 2300. It was able to not only detect the kind of gold once only found with hot VLF detectors, but hit it at depths far exceeding what one of the best hot VLF detectors, the White’s GMT, could attain in this soil. I was literally shaking I was so excited. The large specimen looked to be all gold with no rock showing but was very porous in appearance. Not like steel wool but more like a lot of tiny pieces of gold all lightly stuck together. I could tell it was going to be spectacular when cleaned up, and it later weighed in at just over 24 grams or nearly eight tenths of an ounce. I decided then and there I had found the chunk I would give to the property owners. They certainly deserved it and I still had about an ounce of specimen gold I could take home with me. Steve's share of GPZ gold after initial cleaning - 0.85 ounce Photo emailed to Steve of 0.79 ounce specimen after cleaning People may wonder at this a bit that I would volunteer this piece up when I did not have to, but I believe in taking care of people that take care of me. The day I was having was as good as it gets for metal detecting. I just found 1.6 ounces of gold in less than three hours, was on cloud nine, and wanted everyone to share as much as possible in that experience. To say the property owners were surprised and appreciative would be the understatement of the century. It really just does not get better than that. All this happiness and great times were facilitated through the magic of metal detecting and the extreme capability of one detector in particular. Not to be overlooked however is the SDC 2300 which also shined very much along with the GPZ. My only regret is that I could not tell the claim owners the complete story at that time. Sorry friends, I hope you understand, but now you know the rest of the story! This article started as a thread on the DetectorProspector Forum. Extra information and details may be found there. ~ Steve Herschbach Copyright © 2015 Herschbach Enterprises
  44. 1 point
    Wow, what a dramatic turn of events. After many years of juggling permits and more types of paperwork than one can imagine I screwed up not once but twice and caused our mining claims to be lost! I'm not much for making excuses and bear the responsibility for the mess. Thankfully, I have good friends and partners and so a hanging did not occur. The error was part of a convoluted situation, but suffice it to say you had better get all the facts straight when messing with mining claims on areas closed to mineral entry. The feds are absolutely unforgiving of errors. The story was such that I wrote it up and had it published in the ICMJ Prospecting & Mining Journal. I had big plans for the summer as detailed at Alaska Gold Dredging Adventure 2013 and with the claim now gone there was quite a bit of planning to roll back. I was able to cancel all the equipment on order and return the rest. I had to tell my partners there summer plans were also messed up but suggested various options we could undertake. Not to make light of a bad situation but things are working out. Time to make lemonade out of lemons! I experienced a bit of depression over the whole mess and decided I was fed up with permits and paperwork for the time being. I went so far as to sell out of some other federal claims I was involved in to just get free of it all and spend a year regrouping. I still want to possibly do a dredging operation, but have put it off to 2014 at least while I look at various options. One thing I did decide was that perhaps I was thinking too small with a 6" dredge and so now am mulling over options for placing an 8" dredge someplace. In the meantime I am just going to hang loose and go prospecting, with my main goal to stay mobile and to stick with methods that require no permitting, which generally means staying non-motorized. I am putting together a mobile tent camp and basic prospecting gear including sluice box, recirculating rocker box, and metal detectors. I am going to start in the Fortymile area near Chicken, then head for the Iditarod country, and finish up in the Nome area. I plan small side trips to the Petersville area and Kenai Peninsula if time and circumstances permit. I do intend to use metal detectors for the bulk of my prospecting efforts and am relying on the four units above to put gold in my poke this summer. Gold Bug 2 with 6.5" coil. This will be for scraping/detecting bedrock cleaning up the tiny bits. Gold Bug Pro with 10" x 5" DD coil and 11" x 8" DD coils. General purpose tailings detecting. F75 Special Edition with 13" DD coil and 11" DD coil. General purpose tailings detecting. Minelab GPX 5000 with 8", 11", 16" and 18" mono coils. The "big gun"! For use anywhere there is not too much junk. Fisher Gold Bug 2, Gold Bug Pro, F75 SE, & Minelab GPX 5000 The Gold Bug Pro and F75 are redundant. For most people the Gold Bug Pro is the way to go. But I get a tiny edge with the F75 on larger gold in tailing piles and I like the large target id that pops up on the screen while in all metal mode compared to the tiny indicator on the Gold Bug Pro. The Pro is a tad hotter on small gold than the F75. The bottom line is I could narrow it down to three machines by leaving the F75 behind but can't quite bring myself to do that. The machine has been too good to me so it goes along and I will be using it for much of my detecting. I intend to split my time between hunting old ground to get some gold and doing some true blue sky prospecting looking for undiscovered gold patches. Patch prospecting is common in desert areas but I am unaware of anyone giving it s serious go in Alaska, so figure I may as well give it a shot. The terrain and ground cover do not favor this type of metal detector prospecting in Alaska and so most people stick with hunting old mine workings. The odds on patch hunting here are slim but the potential rewards are great. I have my trusty sluice box, but have also finally acquired a rocker box. I have always wanted one, but did not want a wood homemade unit and have never seen a commercially made rocker i really wanted. Alan Trees recently started making a plastic rocker box which looks really good. I got one for $599 plus $100 shipping to Alaska. I want it for working areas away from water in non-motorized locations and so have paired it up with a 50 gallon tub to use as a water recirculation system. I will fill out more details here later but that is the rough plan for now. I will be hitting the road for Chicken in mid-June and checking in every few weeks with updates ~ Steve Herschbach Copyright © 2013 Herschbach Enterprises
  45. 1 point
    I took the first Minelab GPX 5000 in Alaska up to our new claim on Jack Wade Creek in the historic 40 Mile mining district and did a little detecting. I did not have much time on the trip but still managed to bang out 6 pennyweight (9.4 grams) of gold. The largest nugget is 3.17 pennyweight (4.9 grams). The ground is not very hot on our claims, so I ran in Sharp timings with Gain at 10. The Minelab GPX 5000 had an absolutely rock solid threshold. A far cry from the Minelab "warble" on the SD units. There is not really a whole lot I can say about the unit except to mention the confidence it inspires knowing you have the most powerful nugget detector made in your hands. Once that coil goes over the ground I'm confident I have left nothing behind except the smallest of sub-grain pieces. Gold so small you really can't call them nuggets. I say the ground is not that hot but VLF users would argue with that. It is far hotter than around Anchorage and many VLF units running in all metal constantly sound off on hot rocks here. But by Minelab PI standards it is a piece of cake so the 5000 was able to take in stride without any trouble. I only found one rock that gave a signal in Sharp. If you are in Alaska and have a Minelab GPX 4500 then you are doing pretty good already. The 4500 added a couple timings that have proved very useful in Alaska that earlier models lacked. Sharp for low mineral ground and enhance for high mineral locations like Moore Creek. The 5000 improves the Enhance timing and adds several others. The Fine Gold setting is for getting those last bits out of high mineral locations, hitting small gold Enhance will miss, but it has less benefit in low mineral ground. Our mineralization is so mild south of Anchorage I am anxious to try the new Coin/Relic timings. That was intended for areas with extremely low mineralization and so the thought was it would be more applicable to coin and relic hunting. It is possible that it has applications in those rare low mineral gold nugget locations, but that remains to be seen. First gold found in Alaska with Minelab GPX 5000 I am amazed at how far Minelab has come with PI nugget detecting technology. There is nothing about the GPX 5000 that I can hope will be improved except the discrimination of man-made ferrous junk. Everything else is about all I can expect or hope for knowing what I do of detector technology. Now perhaps Minelab will put some effort into lighter, more compact physical designs to complement the superb electronics at work in the GPX 5000. ~ Steve Herschbach Copyright © 2009 Herschbach Enterprises
  46. 1 point
    I have not been down to Crow Creek Mine for a long time and was curious about what was going on down there. I mainly went to just look around but took my Fisher Gold Bug 2 along to give it a spin. I got a new one recently and wanted to break it in. Since I was chasing tiny gold I put the little 6” elliptical coil on for the trip. The fall colors were out but it was a bit gray and rainy. My first surprise on getting to Girdwood was to find that Crow Creek Road is now paved to where the state maintenance ends, getting rid of a lot of what used to be a section loaded with potholes. Second surprise is that just before getting to Crow Creek there is a huge new parking wayside for the trailhead that goes down to Glacier Creek and the tram that crosses over to the Alyeska side of the valley. Third surprise was that Kate and Nate have really spruced the place up. The old camp at Crow Creek looks better than ever with more relics on display and everything looking much tidier. I visited with Nate for quite some time catching up on news. Then I headed up the creek to find a patch of dirt to work with the Gold Bug 2. By the way, metal detecting at Crow Creek is $20.00 per day, keep all the gold you find - if any! I chose a spot where the creek was undermining the bank and so it was on the steep side. What caught my eye was a layer of loose looking cobbles resting on a layer of finer grained material. I surmised the cobbly material was loose tailings and that the material underneath was virgin ground. At Crow Creek I’ve often found gold where the two meet. So I got in and knocked down a bunch of the cobbles to uncover the layer below. Easy enough to do as the whole bank wanted to come down, so the main challenge was not getting hit by cobbles or falling in the creek. Crow Creek Mine at Girdwood, Alaska The ground here is very low mineral and so the Gold Bug 2 can be cranked up to levels that would not work in many locations. Set for all metal audio boost on, low mineral mode, sensitivity to max, and ground balance about 6 for this spot. I then proceeded to use the coil with no scuff cover like a little rake, scraping down the slope to knock off no more than an inch of material at a time. In just a few minutes I got a sharp little “zip” and quickly used my plastic scoop to isolate a very small nugget weighing maybe a grain. Good deal, the spot has gold! So I continued to slowly and methodically scrape away at the bank, using my pick now and then to dislodge a rock. The rain may have helped as the material was pretty soft and easy to work with the coil alone. Usually I’d have to use the pick to scrape and then check with the detector. About every five minutes I’d get a tiny signal and recover a small nugget. I also got about an equal number of rocks that gave signals but they were much easier to find and eliminate since they were much larger than the nuggets. Most detectors would not have sounded off on them but with the Gold Bug 2 running so hot any mineralization at all in the rocks will be detected. Since these were positive hot rocks they most likely had arsenopyrite in them, which is pretty common at Crow Creek. There was no trash at all in the material, just nuggets and hot rocks. Close-up of gold bearing material and bottom of 6" Gold Bug 2 coil Good use of a plastic scoop is critical as these tiny nuggets can be very hard to find. I use the "divide and conquer" method. Scoop up the material that has the nugget in it. Give the scoop a good shake to get the nugget into the bottom of the scoop. If you have a couple inches of dirt in the scoop and the nugget is on top, you may not be able to detect it when you run the scoop over the coil. I prefer to do this with the bottom of the coil turned upright (just like in the picture) so I can get the scoop right over that hot spot in the middle of the coil. If I confirm the nugget is in the scoop, I dump half in my hand and check again. If it is still in the scoop, I place the material in my hand on the ground where I can check it again later. If the scoop no longer beeps, the nugget is in my hand, in which case I discard the material in the scoop. I just split and check until I'm down to a bit of material, which in the case of these little mud covered nuggets sometimes is just a few little pieces of dirt which have to be check one at a time to find which one has gold in it. Once you get good at this it goes real fast, but care must be taken to not get a nugget in the scoop only to discard it. That is why you put all the dirt in a place where you can check it again when you are done. Sometimes you can get more than one nugget in the scoop at once. Another option is to simply put all targets in a pan and pan it all later. But since I'm following the gold I want to know just where each nugget came from so I prefer to locate them as I find them. I had got a late start and did not want to get home too late so I called it quits after an hour and a half. Once I got back to town I found I had 16 nuggets, the largest being 5.4 grains and the three smallest so small they will not register on my digital powder scale that goes down to 1/10th grain. A total of 17.4 grains in 16 nuggets so this is some small stuff indeed. There are 480 grains in a Troy ounce of gold. Some might question why you would want to go after such small gold. Well, at over $1000.00 per ounce a one grain nugget is now worth over $2.00! So my rather leisurely effort netted me $35.00 worth of gold in a fairly short time. If you follow the little stuff long enough larger pieces do come along. If I’d put in some serious effort for an entire day I think I’d have done very well so I may have to go back soon and do just that. Sixteen little gold nuggets 17.4 grains total The trick is in having a place with mineralization low enough that you can crank up a VLF unit to the max. Higher frequency detectors will do best for the real tiny stuff. Manual ground balance is also preferred as automatic ground balance tends to tune out the tiniest pieces of gold. There really are only two detectors I think are up to this task. If you want the best, use either a 71 kHz Fisher Gold Bug 2 or 50 kHz White's GMT (or earlier 50 kHz Goldmasters) and outfit them with the 4" x 6" accessory coils. Other detectors will hit small gold but nothing as good as either of these detectors. It is also important to get that coil right down in the dirt. Normally I’d recommend a scuff cover for this type of stuff as you can actually wear through the bottom of an expensive coil doing this. But in this case I really wanted to go to the max and so was not even willing to give up the tiny bit of depth lost by using a scuff cover. Which is going too far really as if done properly depth is not really an issue using this method. The idea is to slowly work your way closer and closer to gold that is out of reach until it can be detected. Since the small stuff can only be detected at an inch or less, you have to take the ground off an inch or less at a time, or you’ll scrape gold away. Crow Creek has been detected to death. But there is plenty of gold left to be found only inches down out of reach of detectors. Yeah, it is small stuff, but there is a lot of them and I like finding every one. They do add up, and best of all they keep you interested in what you are doing until a larger nugget comes along. ~ Steve Herschbach Copyright © 2009 Herschbach Enterprises
  47. 1 point
    My wife and I finally took a long-awaited vacation to Hawaii. We returned to the same location we had visited previously on the island of Kauai as it was really our kind of place. My wife mainly likes to lay in the sun and read. I like metal detecting the beaches and surf. So it works out well... she parks herself on the beach and I wander around nearby with my detector. My last trip to Hawaii three years ago produced only one gold ring in two weeks. See the story here for details on that trip. I was determined to do better this time. I took two detectors, my Garrett Infinium LS, and a new Minelab Excalibur 1000. I have a Fisher CZ-20 that I have been very fond of for freshwater hunting, but many have advised me they thought the Excalibur might do better in saltwater than the CZ-20, although the two machines are very close in performance. My main goal was to use the Infinium, but I wanted a back up unit. In particular, I had discovered some beaches off Kauai have lots of iron trash due to the two hurricanes that hit the island in the last twenty years. PI detectors like the Infinium tend to find iron items while VLF detectors are good at tuning it out, and the Excalibur is particularly good in this regard. I was most anxious to use the Infinium after my success with it nugget hunting in Alaska, but the first time in the water with the Infinium it binged and bonged and made all sorts of noise. I thought, "This is a heck of a note" and went and got the Excalibur. I had no patience at that point; I wanted to find stuff now. I found lots of coins with the Excalibur and finally a gold ring. The Excalibur was very quiet and handled the salt water environment about as well as I think a VLF detector can. But the fact is that a salt water/volcanic soil environment like Hawaii severely impacts the performance of VLF units, and so the depth of detection I was seeing with the Excalibur was not what I would be expecting with a PI detector. Detecting heaven - Poipu Beach, Kauai, Hawaii I gave the Infinium a try on the beach to see what the story was there. I found I was getting noise off the salt sand at the end of my swings, and remembered the note in the owner’s manual about this very thing. It is instructed that the discriminate control be advanced to reduce these signals. I was about to say "false signals" but they are nothing of the sort. The Infinium is a particularly sensitive pulse induction detector. If you tune PI detectors up for their best sensitivity to small gold items you run into the area where saltwater, being a low conductive item, also starts to be detected. The Infinium at its zero discriminate setting picks up wet salt sand and saltwater. It is not a false signal, just a response to a low conductive target a less sensitive unit would not detect at all. This effect is enhanced by the 14" coil, which "sees" a large volume of material. By advancing the discriminate control to the point at which the salt effect is tuned out you will get stable operation. In theory this also means that some depth of detection or target strength will be lost on smaller low conductive targets like gold earrings. One thing I need to do in the future is test the Infinium at various disc levels to ascertain the effect on target responses. As a practical matter it does not matter. Just as the sensitivity of a hot VLF detector like the Fisher Gold Bug 2 must be backed off to compensate for high mineral ground, so to the disc control on the Infinium must be set to compensate for the conditions encountered. Hot VLF units cannot be used on wet salt sand at all since they see the salt water as a target and no amount of tuning will get a high frequency VLF to work properly on wet salt sand. Steve with Garrett Infinium on the beach trying 10" x 5" elliptical DD coil I did much like I would with the sensitivity control on a VLF detector. I adjusted the disc control to where I was on the edge of stable operation. In other words, I was running with a bit of background noise. Some people might prefer to go farther to eliminate such noises entirely, but I am used to running "on the edge" so to speak. I found the Infinium with 14" coil set at 3-4 disc level gave not quiet but acceptable background sounds on the beach. I proceeded to dig coins and a small toe ring. As I have found in the past the Infinium really likes nickels. I seem to always find a higher percentage of nickels than I would normally find with a VLF detector when I use the Infinium. This is because it is optimized for targets that fall in the nickel range, like most gold items. Armed with my newfound knowledge I gave the Infinium another try in the surf. And I do mean surf. I had on 40 pounds of weights to help me stay put as the waves crashed into and over me. When I get a target the weights allow me to duck to the bottom and stay put while excavating the target. I use the “fanning” method of blowing sand away with my hand. I’ve tried scoops for this but frankly I’ve got my hands full just hanging on to the detector while working. In high-energy surf the scoops just seem to get in my way. One thing I have heard speculation on is that the 14” coil might be a problem in the water due to its size. That did not prove to be the case for me. The Infinium is weightless underwater and the feel was good. I had no problem using it in very rough surf and in fact often was forced to brace myself on the bottom with the detector. We are talking adverse conditions at their worst, and the Infinium did fine. I found a disc setting of 5-6 was required underwater, and even then the coil needed to be kept parallel to the bottom. When I ducked to the bottom to get a target, the coil would turn up and point off into the water. It could then “see” more salt water, and start to signal. But I was so busy holding on and digging targets I really did not notice this much after a while. Steve suited up for metal detecting in heavy surf But lo and behold, the deep targets started coming… and the rings! First real surf dive of about three hours with the Infinium produced three beauties. An 18K gold and platinum ring was first, followed shortly by a 14K gold ring. Then a lull while I dug a few coins and nails (the Infinium does pick up large elongated iron objects the Excalibur ignores) and then a GREAT BIG GOLD RING! I was over a foot down, and expecting a big chunk of trash, when up pops a large class ring - 1963 U.S. Air Force Academy. It is a 14K gold ring with a large synthetic blue star sapphire. It looked incredibly large underwater, and is the most massive ring I have found to date. I'm working on finding the owner of this one. I was really stoked, but this was Sunday morning, the day before I was to leave. Some beach work with the Infinium and water work with the Excalibur had up until this point produced about 100 coins and one gold ring. But now that I had the Infinium figured out I had three great rings in less than three hours! The surf really beats me up, so I took a break and spent time with my wife. But that afternoon I hit the water again, and up comes an 18K gold ring with a deep blue faceted sapphire and a platinum band. The depths were all in excess of what I feel I was attaining with the Excalibur. I do not want to give the impression I’m knocking the Excalibur. It is a well proven and well thought of detector, and may in fact have the best performance in salt water of any VLF on the market today. But I just do not think a VLF detector with a 10” coil has much chance versus a PI detector with a 14” coil in saltwater environments. We had to check out at noon the next day, but I got up early and gave it one last go. A few more nails, some coins, and on last extra wide 14K gold band. I was ecstatic… it just seemed like I could not miss with the Infinium. In two days I found more nice rings than I've found in any other water detecting I've undertaken. My only regret is I did not try harder with the Infinium right off the bat. I found the Infinium to be a very good saltwater unit, but not having run any pulse units other than the White’s Surfmaster PI in salt water I certainly cannot say how it compares to other PI water detectors. Even the Surf PI I used three years ago has been upgraded to the Surf PI Pro model for enhanced sensitivity to gold items. That fits with what I experienced with the original Surf PI. It got the coins but left me with little gold to show. I would like to try the PI Pro as it is lighter and more streamlined than the Infinium. At $699 list it is also quite the bargain for someone wanting to try a PI detector for water detecting. But the Surf PI Pro also lacks the ground balancing capability and interchangeable coils that make the Infinium so versatile. The key for anyone using the Infinium around salt water will be to get the disc control set properly. I cannot overemphasize this point. It is the single most important adjustment for making the Infinium work in salt water, and my initial lack of knowledge in that regard cost me precious hunting time. I really think the Infinium disc control can be more properly thought of as a sensitivity control, and the key is to back the sensitivity down to a level that gives stable operation. Do not be concerned about lost sensitivity. I think I proved the machine retains plenty of power. But if you are picking up the saltwater itself you certainly will have little luck in detecting anything else. Still, I should add a cautionary note here. The Infinium WAS noisy! That means different things to different people. For me, as a long-time detectorist, it is just a thing to be dealt with, and I am used to running detectors "on edge". In other words, I often tune detectors to their limits, which many times results in noisy and erratic performance. The difference is that I can tell the difference between "good sounds" and "bad sounds". But someone else listening to what I am doing might not hear the difference, just lots of noise. So lest this story sound like a glowing reason to run out and get an Infinium do take note of its noisy performance here. I obviously made it work for me, but some people may not like either the noise, or the amount of discrimination required to reduce the noise to normal levels. For dry land use, especially while nugget detecting, I feel the Infinium is a very good detector. In salt water the results are mixed, and will depend a great deal more on the expertise of the detectorist. The White's Surf PI was a much smoother and easier to operate detector by comparison, and may suit the casual operator more than the Infinium if salt water is the sole intended use. The Excalibur is the only VLF detector I have ever used in salt water. It was much quieter in operation than the Infinium, although it constantly gave multiple tones on each target instead of locking on a single tone. It did a superb job of ignoring iron targets, and if there were enough iron targets it would certainly be the way to go. But the amount of iron I dug with the Infinium was nowhere near the level it would take to discourage me, and the bit of extra depth I feel I was getting with a PI made me feel more than happy to dig the few iron targets. The ratio was no worse than one iron target for every two or three non-iron targets. I think that unless iron trash is a problem PI is the way to go. I'm surprised that Minelab, manufacturer of what many believe are the most powerful PI units in the world, does not build an underwater PI unit. On the other hand, I have some fresh water lakes I hunt in Alaska that are full of iron trash, and I am anxious to use the Excalibur in those lakes. Iron junk, rings, coins, aluminum trash, and lead weights found metal detecting The picture above shows a typical mix of finds, although some of the oversized trash items have already been discarded. The first place I usually head after getting out of the water is the nearest trash can. In fact, I try to make a spectacle of myself disposing of the trash, especially the sharp glass I retrieve. It helps promote the image of detectorists as public servants. Hey, we are just getting this dangerous junk out of here. The iron items were all found with the Infinium. The Excalibur ignores iron better than any detector I have used. The majority of the coins were found with the Excalibur, although the Infinium got its share, especially nickels. Almost all the pull tabs were found with the Infinium, again confirming its power in the gold range. Many rings are identified by metal detectors as pull tabs because of their similarity electronically, and so the Infinium likes them also. Notice also the large fishing sinkers found by both detectors. I gave these to the dive shop I rented my dive gear from. If you are planning on doing some surf detecting in Hawaii, here is how I outfit myself. Obviously you need some kind of underwater detector. I prefer two, as I have had two different underwater detectors leak on me over the years. The chances are slim, but vacations like this are few and far between. It's cheap insurance. I use a neoprene shorty suit while in the water. The water in Hawaii is warm, but it can get chilly if you are fully submerged for some time. I also find the suit helps cushion the weight belts to prevent chafing. I used two weight belts totaling about 40 pounds. The weight belts and suit were rented locally. Each item was $18 for the week, for a total rental of $54.00. Next time I plan to have a suit with long legs to protect my knees while down on the bottom. I wore an old pair of tennis shoes and socks while in the water. There are lots of rocks and coral that can chew your feet up, not to mention spiny animals like sea urchins. This seemed to work very well and I would do the same thing again. I have a mesh bag that I attach to the arm of the detector for targets I retrieve that also has worked very well. It has a hooped metal opening that makes it easy to drop items in the bag, and yet I have never had a problem with anything getting out of the bag. I have a mask and snorkel that I have used for dredging and diving for many years that continues to give good service. The snorkel is a U.S. Divers model that features a water catch and drain system near the top that sheds water caught by waves going over the top. A good idea for surf work. Finally, a good pair of neoprene gloves to protect my hands while digging holes or holding on to coral. The only item I wished I had was a small rock pick. Every once in awhile I would find items that worked down into deep holes in the dead coral bottom. I had to abandon some of these as the items were too far down in the small cavities. A small rock pick would have allowed me to open the holes up to find those items... whatever they were. Time for a safety warning. Surf conditions can be dangerous and working over weighted can be particularly hazardous. It is important to be completely comfortable in the water and to have a realistic knowledge of your limitations. I have made hundreds of SCUBA dives and have thousands of hours on hookah diving systems. I am extremely comfortable in the water and there is little that could happen that would cause me to panic. Do not attempt rough surf conditions without being sure of yourself and your equipment. All found with Garrett Infinium except small gold ring on pinky finger Index Finger - Two 14K gold bands Middle Finger - Platinum band and 18K gold w/faceted sapphire Ring Finger - 14K Class Ring w/synthetic star sapphire and 18K gold & platinum band Pinky Finger - Stainless steel toe ring and 22K gold band (Excalibur) As far as where to hunt? Well, on the beach itself there is a zone up above where everyone sits. Lots of coins there. But if jewelry is the goal you need to get into the body-surf/boogie board zone. And that is pretty much where the waves are breaking. A rock or coral base with no more than about a foot of sand on it would be preferred. You do want some sand to hide items when dropped, but too much and items sink beyond detector range. The sand gets stirred a lot in this zone, and so stuff gets deep pretty fast. Areas where lots of tourists are in the water will generally be more productive than areas the locals frequent. It's a more affluent crowd and one that is more ignorant of the effects of water on jewelry. Just make sure you take time to watch people a lot. Just sit on the beach and watch people at play and where they are doing it. Any of those areas have potential, and the more vigorous the play, the better the potential. It was a great trip, albeit too short. I’m chomping at the bit for another go. I have often gone on nugget hunting trips where it seems like I spend 3/4 of my time getting my bearings, and then really start to score just before I run out of time. This was one of those trips, and between my trip three years ago and this one I think I’m getting a handle on surf detecting now. I can guarantee it won’t be three years before I next hit the surf in search of gold. ~ Steve Herschbach Copyright 2003 Herschbach Enterprises Postscript 3/25/03 - A happy ending to the 1963 U.S. Air Force Academy Class Ring story. The class is celebrating their 40th reunion in 2003, and by contacting the reunion organizer I was able to find the owner of the ring. He lost it 17 years ago while body surfing in Hawaii and sure was surprised to hear his ring had been found. I hope he gets it refinished and wears it to that 40th reunion!
  48. 1 point
    It's now the middle of winter as I write these words. It has been one of the busiest years of my life, and so I've fallen off on keeping up with my Journal entries. Time to do some catch-up. My father Bud Herschbach and partner John Pulling and I took the time to make a few final visits to Moore Creek in September and October before the snow set in. We spent quite a bit of our time on claims work, staking additional ground and readying the property for winter. We now have a total of ten 160 acre claims and three forty acre claims covering what we believe to be the ground with the best potential. Although there is gold on all these claims, only more testing will determine which claims will be worth further development and possible mining. The weather ranged from cold, dreary, rainy fall days to beautiful, clear blue days. Freezing temperatures at night have a bonus in that the mosquito population drops of to levels that are actually bearable in the late fall. Some of the best times to be in Interior Alaska are early spring and late fall because of this. I've always enjoyed fall, with all the colors, and that cool air in the morning seems to add a little extra zest to the days. It's just too bad that falls are usually so short in Alaska, although this year it did extend out later than normal. We really did not get winter weather until November. John was particularly anxious to do some sampling with his highbanker that we flew in to use for test work. We set it up at the edge of the large tailing pond just above camp where we have previously found gold metal detecting and panning. The area has been mining, but the miners did not excavate far enough into the decomposed bedrock, and so digging the rotten bedrock up with shovels was showing some nice gold with pans. We decided running a little more volume through a highbanker would be instructive. There is a fairly large unmined bench deposit at this location that has good potential. Moore Creek claim marker We ran a couple yards of material through the highbanker, with good results. Since the cream of the crop has already been skimmed off here, however, more work remains to be done to determine the potential of the site. A larger volume of virgin material from the bench needs to be tested, but that will have to wait for 2004 after we get all our permits in order. For now, it was certainly encouraging to see some gold. More sampling in the immediate area of the cabin at camp returned similar results where the old miners did not excavate enough bedrock to get all the gold. We also made time to do some metal detecting, of course. My father used his Tesoro Lobo SuperTRAQ, plus tried my Minelab GP 3000 and Garrett Infinium. John experimented with the Troy Shadow X5, Fisher Impulse, and Fisher Gold Bug 2. This trip I favored my Garrett Infinium. I did use my Minelab GP 3000 also but I wanted to give the Infinium a good try at Moore Creek. Although I believe the GP 3000 with its large coils has superior depth on large nuggets, I like the Garrett for working in the rain (it's totally waterproof) and in thick brush. It does not get the depth of the Minelab but is better than the VLFs so it falls in the middle performance wise. In any case, while I knew I would do well using the Minelab, I decided to just stick with the Infinium the majority of the time just to see what it could do. Testing the bench deposits with a highbanker As you can see I usually hip mount the unit so there is less weight on my arm. About the only time I would use the unit in one piece would be if I were doing some sort of work where I was constantly picking the detector up and setting it back down again. Sometimes I'll work a likely location by spending quite a bit of time removing rubble or scraping off surface material with a rake, then taking a few minutes to scan the area with the detector. Then back to digging or scraping. In situations like this it is nice to have a unit you can pick up, use a few minutes, and set back down again, without having to strap on a control box or battery pack. But for normal use the hip mount is the way to go, as the waterproof control box with it's included batteries is a bit heavy for long hours of use. Garrett has released a coil cover for the 14" coil which came in handy, as the open coil design would normally like to hang up on low lying brush. I also used the new 10" x 5" DD elliptical coil which is very light in weight, and more pleasant to use than the epoxy filled stock coil. The 14" coil balances well with the unit assembled in one piece, but it is "nose heavy" when the control box is hip mounted as you no longer have the control box to balance out the weight of the coil. I really wish Garrett or a third party would produce a large coil for the Infinium that is not epoxy filled. A coil like the Coiltek UFO 24" x 12" open-spoke design I use with my GP 3000 would be ideal. Steve with Garrett Infinium at Moore Creek The smaller coil worked great around the base of bushes and around rocks. In general I favored the larger coil though as it covers more ground and I'm certain it hits larger nuggets a bit deeper than the smaller coil. The smaller coil is a little "hotter" than the stock coil but this means it also tends to give a weak signal on some hot rocks that the larger coil ignores. Still, it is a great little coil, and is the one to use for tight areas and for slightly smaller nuggets than the 14" coil may be good for. The Infinium ran quiet in the mixed hot rocks at Moore Creek, with only a couple that gave a signal with the 14" coil. Hi-lo tones were either gold or slivers of steel. Larger pieces of steel and iron, including nails, gave a lo-hi tone. Theoretically a large enough nugget might give a lo-hi tone but all mine have been steel so far or aluminum cans. I pretty much dug everything but as I do so I'm finding my faith in the dual tone id is growing. If trash was thick I'd ignore lo-hi tones and be pretty confident of not missing gold. But always remember, that no discrimination system is 100% accurate, and so if the amount of trash is acceptable, digging it all is the only sure way not to leave a nugget behind. The results with the Infinium were seven nuggets totaling 4.11 ounces of gold. The largest nugget is 1.5 oz and the second largest 1 oz. I did find one nugget with the GP 3000 that weighed 1.26 oz. By the way, although I'm calling these nuggets, they are really more properly termed gold quartz specimens (in my opinion). These have been cleaned to remove the rust staining they pick up from sitting in the soil for ????? years and so reflect the actual color of the quartz better than my previous pictures. The enclosing rock is grayish quartz and sometimes bits of the quartz monzonite that the quartz veins are eroding out of. Quartz monzonite is a "salt & pepper" looking type of igneous rock, much like granite in appearance. I did better than I expected, as looking for gold was secondary to claim staking and winterizing the camp. But my hot streak from my previous visit continued, and I ended up with some nice nuggets. One nice thing about larger nuggets is that I actually only found eight nuggets total... but they added up to 5.37 ounces. 5.37 ounce gold specimens found at Moore Creek with Garrett Infinium Results with the other detectors helped confirm this is an area for ground balancing pulse induction (PI) detectors like the Minelab SD/GP detectors or the Infinium. The Troy X5 was not happy at all with the hot rocks. I was most interested in Johns use of the Fisher Impulse. The Impulse is similar to the many PI detectors on the market for diving use. In theory they can be used for prospecting, and many people ask about them for just that reason. But the lack of ground balance means they actually do not do well for prospecting mineralized areas, and the Impulse hit the rocks at Moore Creek nearly as much as the VLF detectors. The Lobo and Gold Bug 2 were useable primarily due to their iron discrimination modes. In all-metal they were extremely noisy, but set with iron rejection cranked in they worked fairly well, although with lots of pops and snaps of hot rocks breaking through the discrimination. Luckily the noises are discernable from the clean sound of a gold nugget. The biggest problem is that any nuggets near or under hot rocks are just plain going to get missed with VLF detectors at Moore Creek. My father scored a couple nuggets totaling 0.65 oz with his Tesoro Lobo and John got about 2.5 oz with his Fisher Gold Bug 2. Both are now looking to get the Infinium for next year. The Minelab is a fine machine, but they are more comfortable with the price/performance ratio of the Infinium. Lots of bang for under $1000 and simple to operate. So it looks like there will be lots of Infinium gold to report from Moore Creek next summer. I'm sure I'll be using my GP 3000 as my primary unit, with the Infinium filling in the niches. It's the machine for sure for rainy days, and I think I'll even jump in some tailing ponds with mask and snorkel and nugget hunt underwater. For me the GP 3000 and Infinium are a great match for Moore Creek, each excelling where the other is weak. We finally had to give up on detecting in September and get all our final claim staking done. It is a lot of work but compared to the old days it is easy due to the ability to use GPS while staking state mining claims. Our final days in early October were really nice. I like those crisp fall mornings, color on all the leaves, and the bugs basically all gone. We staked up new claims plus re-filed on the original prospecting sites that we purchased to convert them to mining claims. These prospecting sites constitute the core property at Moore Creek and since prospecting sites are only valid for a short time it was time to get them converted to claim status. Then it finally came time to wrap up the camp for winter and go home one last time. As I noted at the start of this entry, it's now the middle of winter. All I can do now is work on permits and wait for spring to come to Alaska... and dream about the gold yet to be found! ~ Steve Herschbach Copyright © 2003 Herschbach Enterprises
  49. 1 point
    The snow has finally melted enough to let me try out my new White's Electronics Goldmaster GMT and several coils. The GMT is my newest nugget detector. I really like the GMT's fast automatic ground balance and advanced iron id capabilities. But most of all it has much better depth of detection on larger gold than my old Fisher Gold Bug 2, and so I'm hoping to eke some deeper nuggets out of some areas, especially some of those places that also have lots of iron trash. I went to Crow Creek Mine near Anchorage, Alaska. A good local site, but hammered by detectors over the years. It's getting to where you have to dig to find nuggets with a detector rather then just scan the surface. Excavating slowly into an area and checking the material with the detector as you go pays off more often now. I wanted to try several things. My first plan was to use the Sierra Gold Max coil to carefully scan areas that have been detected before, hoping to find a larger nugget down just a bit deeper than others may have detected. A real long-shot at Crow Creek, but I try it now and then. The reason I say it is a long-shot is that pennyweight plus nuggets are pretty rare at Crow Creek anyway, and betting someone missed them in the heavily searched areas is a poor bet indeed. But you never know unless you try. There was still a lot of snow at the mine, so I spent the first half of the day with the big coil hitting south facing slopes. The going was as steep as I could handle, and my chest mount setup was welcome. It was steep enough I would find decent footing, then scan in all directions as far as I could reach. Keeping the weight off my arm was a big plus. But a half day of this mountain goat detecting revealed not a single nugget. Area #1 at Crow Creek Mine, early spring My arm got tired, and so I put the stock DD coil back on and headed for a little flatter ground. There are lots of brushy areas at Crow Creek that are relatively open right after the snow melts off, but which will be jungle-thick after the new brush grows up in a few weeks. I worked in among the alders hoping for a nugget. The whole area was stripped with hydraulic giants, but the brush has dropped a couple inches decomposed organic cover over the old tailings. Trying to detect through this couple inches of cover means little chance of hitting small gold, but again I was hoping for a larger nugget. But except for a few bullets and some foil, again no gold. There is still too much snow in the underbrush, however, so I'll try some more in a couple weeks. The GMT worked extremely well with the large coils, and the automatic ground balance worked well at maintaining smooth performance, especially in the organic material and roots in the underbrush area. Extra large coils often have more problems with ground mineralization, and the automatic ground balance looks like the best way to go with the largest coils. Here is a picture of my tools for the day. My GMT is modified for chest mount use, and so it looks a bit different than the unit most are used to. Since the GMT is not normally convertible to a chest mount I did the conversion myself - details here. I almost always use headphones. My favorite pick for rough terrain is the Hodan walking pick, as its extra long handle is great on hills and for crossing streams. I have a super magnet clamped on the digging head to suck nails out of the ground while I dig. And for finding those little nuggets quickly I always have a nugget scoop stuck in my back pocket. The spare coils go in my rucksack with the camera, bug dope, first aid kit, and snacks. I usually have at least one spare coil along when detecting. Don't forget those coil covers. Steve's White's GMT, converted to chestmount By now it was 3:30 PM and I still had no gold to show. My answer for this in the past has been to use my Gold Bug 2 with small coil and scrape into some pay layers. I saw some likely areas in all my prospecting throughout the day, and so I figured it was time to really give the little 6" prototype coil a workout. I've long wanted a small coil for the Goldmasters, and my getting my hands on this experimental small coil was instrumental in my purchasing the new detector. The first couple spots I tried did not reveal any gold, but the third had a nice little clay layer, and after a few minutes I found my first nugget with my new GMT. In less than two hours I excavated 10 nuggets from the layer, the largest just under a pennyweight, and the smallest a half grain. The ground is very moderate at Crow Creek, and I had no problem running the gain maxed out. I ran the SAT at minimum, and audio boost on. The coil was smooth and quiet, in fact surprisingly so, considering how high I had the sensitivity set. The big thing about the GMT is the auto ground balance. It works very well, but it really tunes out small nuggets fast when trying to pinpoint them. As long as I scanned it would hit the nuggets just fine on the first pass, but they would tend to fade when trying to zero in on them. I played with both manual balance and automatic quite a bit. It proved easier to just use manual while working a small area like I was, rather than switching back and forth. Switching is very easy, however. Just squeeze the trigger switch and the ground balance "locks" at it's current setting. It would all depend on the ground as to what might be the best method. Close up of White's GMT converted to chest mount I found earlier in the day that the automatic would tend to tune out hot rocks and iron targets to varying degrees. As long as the sweeps are wide and the system is getting an average ground reading it signals well on targets. Then when zeroing in on them they tend to fade in distinct ways depending on what the items are. I still need more time with the detector, but I felt like I could sense differences in the way hot rocks, iron trash, and gold responded with the automatic ground balance engaged. It is an extremely fast automatic ground balance, much faster than others I have used, and so it seems to have some interesting properties of its own. I'm looking forward to working with it more. All in all I ended up feeling the automatic ground balance is well worth having on the GMT, and there are times when I would really like it, particularly when hunting larger gold with the large coils. But at the same time it is very nice to be able to run the GMT in manual balance mode if desired. In moderate ground manual tuning works just fine, and for the tiniest gold I think it is mandatory to be able to manually tweak the ground balance. This is especially handy if you want to run with a slightly positive balance, which is impossible to do with most automatic units. The bottom line is you get the best of both worlds with the GMT. Thanks, White's! In any case, I found the small coil to be extremely effective, and very much on par with what I've learned to expect from my Gold Bug 2 with small coil. The most remarkable thing about the little coil was how stable it was. I rubbed it and knocked it with nary a false signal. I can see that this little coil is going to get a lot of use in the future, as it's ideal for the normal Crow Creek "dig and detect" method. I hope White's produces a coil like this for the Goldmasters, and am just thrilled that I have one to play with. Steve's first gold found with White's GMT So here is the gold. The smallest nuggets are .5 grain, .9 grain, 1.6 grain, and two at 2.1 grains. The largest is 23.4 grains and the next 18.2 grains. Total weight 64 grains, or about 2.5 pennyweight. Not bad for my first outing with a new detector, and a good start to a new detecting season. And now that I've located some new areas to detect at Crow Creek I can't wait to get back and find some more gold! Steve Herschbach Copyright © 2002 Herschbach Enterprises
  50. 1 point
    The owner of the High Grade lode mine in Hatcher Pass stopped by the store. He was interested in buying a metal detector to aid in hardrock prospecting. I’ve done a bit of this before, and realize how hard it can be for a beginner to get results. I offered to meet him at the mine last Sunday to demonstrate what I could do on his mine dump. If he liked what he saw, great. If not, he would save the price of a detector, and I would still get a fun trip out of town. I took my to the mine under gathering clouds. When chasing tiny gold enclosed in quartz a high frequency detector like the White's Goldmaster with a small coil is the way to go. The High Grade is up behind the Independence and Gold Cord mines at Hatcher Pass. The High Grade was named because it literally produced some very high-grade ore. The veins were narrow, however, and the mine only produced a limited amount of ore. The dump had so much iron trash in it that I found it easier to simply pick up quartz samples and wave them over the detector search coil. The ore in Hatcher Pass is relatively clean quartz with free gold. The gold does tend to associate with pyrite, so any quartz with reddish staining or obvious sulphides is worth extra attention. The pyrite here is non-conductive, and so will be ignored by the detector. Many very rich samples, such as those pictured, have little or no pyrite; so all quartz should be detected. I have seen gold in perfectly pure, white quartz in the area. In less than an hour I found eight pieces of quartz that gave obvious signals. Some had visible gold, while others were giving signals from gold totally enclosed within the quartz. Unfortunately, rain began to fall, and then it REALLY began to fall. I was not prepared for rain, but we had proven the point… the detector worked very well on the ore. I headed on home. I left the ore with the owner. BLM is putting the squeeze on him, so I figure he needs all the samples he can get. The ore pictured below is from the Fern Mine, also in Hatcher Pass. I obtained it from a geologist that worked the mine years ago. It is shot through with gold, and is a good example of what might be found by a lucky prospector in the Hatcher Pass area. It exhibits black streaking that is often associated with the better ore in the area. High Grade Mine, Hatcher Pass, Alaska An excellent source of additional information is Hatcher Pass Gold by Ron Wendt. Ron tells about all the mines in the area, and includes many maps and photos. The book is out of print but can be found used. ee also the USGS report for the area - Geology and Ore Deposits of the Willow Creek Mining District, Alaska (1954). Be aware that most of the hardrock mines in Hatcher Pass are patented properties. In other words, they are no longer just mining claims, but actually are private property. Few of the mines in the area are ''abandoned'' and permission should be sought from the mine owners to sample the mine dumps. Use extreme caution around the old mines, as many tunnels, shafts, and old structures present a hazard to the unwary. How was the gold deposited at Hatcher Pass? What follows is a simplified view of gold deposition. In reality is this is all theory, and entire books are devoted to the many theories of how gold deposits form. So what I am presenting below is a layman's view of a commonly accepted theory... not a "fact". Still, the theory works well enough to be used to predict where gold occurs. Gold most commonly occurs in quartz veins. The quartz and gold were deposited within crevices and fractures in rock far below the earth by circulating hot water. You will see the term "hydrothermal" a lot. hydro = water + thermal = hot. Most gold was formed by hydrothermal processes. Note that most quartz veins do not contain gold, so quartz alone means little. So we need two things... rock with crevices and fractures, and a source of hot, mineral laden water. The classic gold deposit is the hardrock mine area at Hatcher Pass north of Anchorage. A large mass of molten rock, in this case granite, rose towards the surface from far below. This kind of activity tends to result in a pattern of fractures or faults in the surrounding rock as this molten mass forces it's way upward. When this mass of molten rock cools, it shrinks, and more fractures form within this rock as it cools. What finally results is a "granitic intrusive", another term you will see often when reading about gold deposits. The hardrock deposits at Hatcher Pass are a were formed around a granitic intrusive. As the molten rock cools, water seeping down from the surface reaches the zone of newly introduced minerals and heat. Water that is extremely hot and under pressure can dissolve many minerals that we think of as insoluble, especially when some of the dissolved minerals cause the solution to become even more corrosive. The water, now mineral-laden and hot, rises back towards the surface. As it circulates through the crevices and faults in the rock it deposits many of these minerals. Much of the mineralization is simply because the solution is cooling, and so can no longer keep the minerals in solution. Often, in the case of rich mineral deposits, the solution comes into contact with another type of mineral that causes a chemical reaction. The classic mineral in this case is limestone. Many of these solutions are acidic, and when they come into contact with limestone, the acidity is neutralized, and the mineral drop out of solution. Many very rich mineral deposits have been found where limestone comes into contact with other rock types. Gold ore from Fern Mine, Hatcher Pass, Willow Creek Mining District, Alaska In the case of Hatcher Pass, the deposit follows the classic example. There was a rounded mass of granite far underground. Fractures formed in the top of the granite, and in the other rocks immediately above and around the granite. Hot water solutions deposited quartz and gold in these fractures. Ages of erosion exposed the top of the granite and the fractures to the surface. Erosion released the gold from the veins and deposited some of it in the streams and rivers in the valley. The rest remained in the hardrock veins, to later be discovered and mined. Very common in this scenario also, is the concept that the gold veins have a limited depth. The gold veins tend to occur just above and within the upper layer of the granitic mass. As erosion (or mining) extends downwards below a certain level, the gold deposits tend to thin out and disappear. A situation arises where areas that have extensive gold in the streams often have little in the rock (it all eroded out) and areas where the stream deposits are poor will often be associated with very rich hardrock mines (most of the gold is still in the rock). Again, a generality. Granitic intrusives are common along major fault lines. Maps can readily be had of faults and their related intrusives, and it is no surprise these tend to coincide with many of the major gold regions of the world. Volcanoes are another process where by molten rock rises to the surface, surrounding rocks are fractured, and circulating waters deposits minerals, including gold, in these fractures. The oldest hardrock mine in Alaska is the Apollo Mine on Shumagin Island in the Aleutians, near Sand Point. This and other gold deposits in the Aleutians and the Alaska Range are volcanic in origin. The Aleutians are a "volcanic chain", a long string of islands that are actually volcanoes. There are many other types of gold deposits, and many variations on these types. The best reference I have seen on the subject is "The Geochemistry of Gold and its Deposits" by R. W. Boyle, (1979) Geological Survey of Canada, Bulletin 280, 584 pages. ~ Steve Herschbach Copyright © 2000 Herschbach Enterprises
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