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Found 170 results

  1. Legendary metal detector engineer George Payne laid the foundations for much of what we consider to be modern metal detector technology. He or companies he worked for hold a host of basic patents. I tripped over this old lawsuit between White's Electronics and the old Teknetics company (acquired by First Texas in later years) over George's invention of basic target discrimination / target id technology. The following is from the public record of the legal findings at https://law.justia.com/cases/oregon/court-of-appeals/1984/677-p-2d-68.html: I thought it provided an interesting peek at some early industry history and so here you go..... Decided February 22, 1984. *69 J. Pierre Kolisch, Portland, argued the cause for appellant. With him on the briefs were Jon M. Dickinson, Francine H. Gray and Kolisch, Hartwell & Dickinson, Portland. Edward T. Monks, Eugene, argued the cause for respondents. With him on the brief were Kenneth A. Morrow, Morrow, McCrea & Divita, Eugene, and Gary S. Kindness, Seattle, Wash., of counsel. Before GILLETTE, P.J., and WARDEN and YOUNG, JJ. GILLETTE, Presiding Judge. Plaintiff White's Electronics, Inc. (White's) commenced this action seeking the imposition of a constructive trust for its benefit in all rights, patentable or otherwise relating to an invention developed by defendant George Payne. White's also sought an injunction restraining defendants from selling any product embodying such an invention and from using any trade secrets or other proprietary information belonging to plaintiff. The trial court denied White's any relief. We affirm. White's is a manufacturer of metal detectors. In 1969, White's hired Payne, an electrical engineer, to invent new metal detector technology. In 1971, Payne signed *70 an employment agreement with White's that stated that he would assign to White's any invention that he developed during and for six months after termination of his employment that related to White's activities or was the result of tasks assigned by it. During this period of employment, Payne assigned to White's two patents covering inventions pertaining to metal detectors. In mid-1976, he terminated his employment and went to work for Bounty Hunters, one of White's competitors. He remained there until late 1978, when he sought reemployment with White's. Because of a noncompetition agreement with Bounty Hunters, he did not become reemployed by White's until January, 1980. He did, however, work as a consultant for White's during the intervening period. When Payne was rehired, he did not sign a new employment agreement. As during his previous employment, he worked to develop innovations in the metal detector field and to solve problems related to White's product line. He assigned one patent to White's during this employment period. The evidence concerning the events of January, 1981, is both conflicting and confusing. Payne testified that on January 9, 1981, he conceived an idea that would enable a metal detector automatically to provide the user with target identifying information, unlike any detector then on the market. He stated that he told defendant Morris, White's marketing manager, of his idea, but that he did not work any further on its development until January 15, when he assembled a breadboard a board containing electrical circuits to test his idea. The breadboard failed to achieve the desired result. On January 17, 1981, following a period of internal management disruption at White's, Payne and Morris both quit. Payne testified that, on January 19, 1981, while working to develop his idea of January 9, he "found something that is going to make this thing work, or allow me to continue development of it." He stated that, following this "breakthrough," he still had to work for many more months before his concept was perfected. On January 28, 1981, Payne and Morris, along with defendant Smith, organized defendant Teknetics, Inc., to market metal detectors in direct competition with White's. In December, 1981, Teknetics introduced a metal detector which incorporated Payne's target-identification concept. Plaintiff contends that Payne's "breakthrough" on January 19, actually occurred earlier while he was still employed by White's. In support of this contention, plaintiff introduced Payne's engineering notes containing circuitry designs dated January 18, 1981. Payne admitted that the date on those notes was in error and that they were probably prepared sometime before the 18th. Plaintiff's expert, an electronics engineer, testified that he or someone similarly skilled could build a target-identification circuit based on the information provided in the drawing. Payne testified to the contrary, stating that the key element to his target-identification concept did not appear in his notes until January 19, after he had left White's employ. The trial court found that Payne conceived his target-identification concept on January 9, but that he did not exert time and effort to develop it until after January 17, the date he left White's employ. According to the court: "The idea achieved the status of invention sometime in March of 1981, as evidenced by the order for print out circuitry systems from another company. Prior to reaching this posture, [Payne] had to address himself to and solve problems of target identification as they related to ground rejection." The trial court concluded from the foregoing that plaintiff was not entitled to either the assignment of the patent or the imposition of a "shop-right." This appeal followed. Absent an agreement to the contrary, an employe who is hired to invent, and who succeeds during his term of service in accomplishing that task, is bound to assign to the employer all rights in the *71 invention. United States v. Dubilier Corp., 289 U.S. 178, 187, 53 S. Ct. 554, 557, 77 L. Ed. 1114 (1933); Mainland Industries v. Timberland Mach., & Eng., 58 Or. App. 585, 589, 649 P.2d 613, rev. den. 213 Or. 801 (1982), cert. denied ___ U.S. ___, 103 S. Ct. 1498, 75 L. Ed. 2d 930 (1983). Furthermore, the practice by an employe of assigning patents to an employer constitutes persuasive evidence of a duty to assign. Mainland Industries v. Timberland Mach. & Eng., supra, 58 Or. App. at 591, 649 P.2d 613. In this case, when Payne was rehired by White's in 1980, no new employment agreement was executed. Although Kenneth G. White, president of White's testified that he intended to rehire Payne on the same terms as his previous employment, the issue apparently was never discussed by the parties. The evidence is insufficient to support a conclusion that the 1971 agreement was revived by Payne's reemployment. However, even without an express agreement, we find that Payne was obliged to assign to White's inventions created during his employment. Payne was hired precisely because of his exceptional inventive abilities in the metal detector field. His duties were to invent and develop improvements in White's product line. This, in conjunction with Payne's practice of assigning patents to White's, including during his last period of employment, convinces us that he had a duty to assign all inventions arising during his employment. Thus, the central issue in this case is whether Payne's target-identification concept was sufficiently developed at the time he left White's employ so as to constitute an "invention" to which White's is entitled. Because White's is seeking the imposition of a constructive trust, it must prove its case by strong, clear and convincing evidence. Pantano v. Obbiso, 283 Or. 83, 87, 580 P.2d 1026 (1978). We are unable to find any Oregon cases dealing directly with this issue. Both sides cites numerous cases from other jurisdictions in which the term "invention" has been defined under a variety of factual circumstances. Most courts have adopted a definition which requires that an invention be something more than a thought in an inventor's mind. As stated in National Development Co. v. Gray, 316 Mass. 240, 55 N.E.2d 783 (1944): "Of course there is a distinction between the conception of an idea and the reduction of the idea into practice. The idea is only the starting point, and it does not become an invention until it is developed and perfected and becomes embodied in some tangible form which becomes some novel and useful device or process." 316 Mass. at 249, 55 N.E.2d 783. In Gray, on which plaintiff places great reliance, defendant Lawson, an employe of a company that manufactured shoe-heeling machinery, conceived of an idea for an improved model of that kind of machine while he was in that company's employ. Before he quit, he had reduced his idea to a drawing. The court ruled that, even though he had not yet constructed a working model of the machine, "* * * the idea had crystallized into such definite form by the time Lawson left the plaintiff's employment that he and those with whom he spoke concerning the new machine knew in a general way the principles governing its operation and its probable practical value. * * "It is plain from the evidence * * * that the drawing was the nucleus from which the machine emerged; that whatever Lawson accomplished up to the time he quit belonged to plaintiff, * * * that the activity of Lawson in reference to the new machine constituted a breach of his contract with the plaintiff; and that the latter was entitled to the patent." 316 Mass. at 250, 55 N.E.2d 783. We find the National Development Co. analysis helpful, but we reach a different result as an evidentiary matter. In our view, the evidence in the present case is not clear and convincing that the unsuccessful breadboard Payne assembled prior to his leaving White's employ was the "nucleus" *72 from which his target-identification concept emerged. We are not convinced that, at the time Payne left White's, his idea had "crystallized into a definite form." In fact, one of the key elements of the idea was not developed until after his resignation. When Payne left White's he left with an idea and a goal, but not with an invention. White's, therefore, is not entitled to a constructive trust or to assignment of the patent. White's argues that such a holding will encourage employed inventors deliberately to refrain from putting ideas into tangible form in order to circumvent employer's rights. Our response is that employers could protect themselves by requiring inventors to enter into contracts that provide that the employer is entitled to any inventions conceived during the term of employment and during a reasonable period of time after termination. In fact, White's required Payne to sign such an agreement during his first period of employment. Its failure to obtain such an agreement the second time around is fatal to its case. White's contends in the alternative that it is entitled to a "shop-right" in Payne's target-identification concept. A "shop-right" is a non-assignable license to a patent granted to an employer when an employe who works in a general or noninventive capacity creates an invention using the employer's time and materials. Mainland Industries v. Timberland Mach. & Eng., supra, 58 Or. App. at 593, 649 P.2d 613. Payne, however, was hired specifically as an engineer whose duties included inventing and developing improvements in White's product line. Thus, the facts do not warrant the application of the "shop-right" doctrine. White's final contention is that it is entitled to a permanent injunction to prevent defendants from using trade secrets, propriety knowhow or confidential information acquired from White's. Our review of the record does not reveal any evidence to support the granting of such an injunction. Affirmed.
  2. Anyone out there know any information on this machine ? It supposed to be being tested and could be really interesting when released . May be able to discriminate Iron out . You Tube this . AQUAMANTA A1 TESTS HARDELOT . All in capitals . It is compared to the Sovereign and CTX , the Aqua is the last one tested . Unfortunately LIKE the Equinox most of the time before release , its in a foreign language .
  3. Maybe this is a dumb question wit regard to PI machines why is that one machine will excel at small nuggets but can't do so well on bigger nuggets., Doesn't make sense to me. It would seem logical that iit can find small stuff big stuff should be easy?
  4. The ads came from mags dating back to 66. I can say I remember them all. Just maybe you remember some if not all. Chuck
  5. Has anyone had any experience with these things? Electromagnetic and magnetic interferences could be extremely annoying when you are looking for that hard to find gold nugget. Most of the noise is picked up by the search coil but a significant level of noise is being picked up as well by the sensitive electronics inside the control box. The control box is made of aluminium therefore the magnetic field easily penetrates it. To prove that, approach a magnet to the right side of your detector when switched on. Millions of less obvious noise signals are interfering with your detector. We have developed this Shield from the best quality material primarily used in sensitive medical and scientific electronics. After years of studying and testing different materials we have found this one ticks all the boxes. I have revisited the places where I've previously cleaned up and found more gold after installing the shield. It is 0.35 mm thick, held firmly around your control box by the armrest and the new improved version with dual layer shielding on the right side is only 175 g! We have tested it on the GPX 5000 with amazing results such as quieter threshold, better GB, resulting in slightly increased depth. The shield allows you to increase the Rx gain by a notch or two without compromising the threshold. Use Inverted Response when hunting for big deep nuggets. https://www.ebay.com.au/itm/MAGNETIC-INTERFERENCE-REDUCER-SHIELD-FOR-MINELAB-GOLD-DETECTORS/232594646908?hash=item3627b8a77c:g:8lEAAOSwYGFU0bvu I noticed it on Ebay today while I was looking for a cover for my GPX. I have noticed I've been able to quieten down my GPX by opening the control box up and scraping some paint away where the shielding touches the casing, on one end they had scraped away paint from one screw point during production, and the other end had no paint scraped away at all by the factory so it's sheilding was basically useless. By scraping paint away from a few areas on each end of the detector I was able to give the GPX a bit of a noticable quieten down. I am sure on later models Minelab would of scraped away more paint but as mine is a very early model made in Australia version this wasn't done.
  6. We just went through a few years on constant releases of new prospecting detectors. And now the flood has subsided, with almost nothing on the horizon. There is the “any moment now” Makro Gold Kruzer, running at 61 kHz and waterproof to 15 feet. After that however it gets pretty thin. First Texas has new detectors in the works, but nothing rumored that is aimed specifically at prospecting this year, but maybe later. Right now a PI beach detector appears to be up next. Garrett - maybe they are working on it but personally I have given up waiting on a lighter weight ATX. Tesoro - nothing going to happen there obviously. Minelab still “owes” us GPZ owners a smaller coil but with Equinox occupying all their efforts....? Nok/Mak outside of the Gold Kruzer has been working on a PI for years, but absolutely no hints on it getting any closer to market. XP I thought might bring a version of the low cost DPR 600 to first world markets but no sign of it happening. And White’s? Who knows. Maybe we will see a repackaged GMT but the shine has worn off of repackaged detectors these days. Long story short is it often takes new detectors to stir up activity on forums. For now at least the future is looking pretty quiet. The good news is we can just focus on using what we already have to best effect without being tempted or distracted by new shiny toys!
  7. Hi Steve: Just re-read your "Steve's Guide to Threshold, Autotune..." It helped a lot. Thanks. I do have a question though. I understand V/SAT. It's about how fast autotune re-adjusts the threshold after encountering some disturbance like a target. However, I'm unclear on how that relates to Ground Balancing and Tracking. It sounds like they are the same. Would you please explain that? Thanks
  8. If you read between the lines on the various search modes, Minelab seems to imply that the ground balancing is done automagically, regardless of whether you do a ground grab or not. For example: Park 1 Multi-IQ processes a lower frequency weighting of the multi-frequency signal, as well as using algorithms that maximise ground balancing for soil, to achieve the best signal to noise ratio. Hence Park 1 is most suited for general detecting and coin hunting. Park 2 Multi-IQ processes a higher frequency weighted multi-frequency signal while ground balancing for soil. Field 1 Multi-IQ processes a lower frequency weighted multi-frequency signal, 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 and coin hunting. Field 2 Multi-IQ processes a higher frequency weighted multifrequency signal while ground balancing for soil. Beach 1 Multi-IQ processes a low frequency weighted multi-frequency signal, and uses special algorithms to maximise ground balancing for salt. Beach 2 MultiIQ processes a very low weighted multi-frequency combination, using the same algorithms as Beach 1 to maximise ground balancing for salt. Not to be confused with auto tracking, but it appears that the Equinox is doing some ground balancing specific to each search mode irregardless of whether you do a ground grab (auto ground balance in EQ speak) or not. Not that I would skip doing a ground grab, but I find it interesting that Minelab seems to be implying they process the ground balancing differently for each search mode, even if you don't do it. Steve do you see this as the case?
  9. This may seem crazy or even funny but I was watching a TV Show last night called Untold Stories of the ER. A Patient entered the hospital by ambulance that had been shot in New York while out on the town Friday night drinking, they were using an Ultrasound to try find the bullet in the area of the entry hole but it was nowhere to be found. After a HUGE amount of messing around with a handheld ultrasound machine for considerable time they ended up finding the bullet have travelled down an artery into the guys leg. They then decided they'd just cut the guys leg open and try find the bullet by hand, digging around in his leg with the surgeons fingers trying to find it, The surgeon was having a great deal of trouble finding it. I was amazed they haven't got some sort of medical metal detector for this purpose yet. I seem to be able to find bullets when I'm trying not to. If I was the surgeon on this show I could of used my Garrett Carrot and found that bullet in seconds, without having to rummage around in his body with my fingers all over the place to try find it. The guy almost lost his leg as the artery was blocked for so long by the bullet causing no blood to go to his lower leg. Seems an opportunity being wasted by metal detecting manufacturers to me, you would think there would be big money in it.
  10. What are some of the least expensive pi machines? Can used ones be found?
  11. Hello , It would be great if the youtubers like calabash and others who have lot of followers make a video of that to share at maximum . - Take 12-15 differents coins of your country ( the coins you use all the day ) -Make a pile (heap ?) with that coins ,like a little tower -Keep this pile beetween your thumb and other finger . -Swing that in front of the coil , at 3-4 inches , the side of the coins ! -Now try that with all the detect mode , not need to change factory presets ( maybe only the accept to 0,1,2 in field 2 ) , you are free to try differents settings later . -The only and important setting for the moment is to change frequency , try 5,10,15,20,40 and multi in each detect mode . Of course multi in the two beach and 20,40,mutli in gold . What is happening ? I know the results , but i want to know the result of the coins of USA,England, australia ,canada .... So please share your results in comments or video Make that with different detectors , if you have impact or deus or other who have various frequency , try to switch all frequency . You can try that with HF white coil if you have , but .... The conclusion is multi IQ obsolete the others single freq . It is more or less to say what calabash said in his video . We can debate of that .
  12. Subject came up elsewhere so I thought I would run a little poll. The poll only gives you two choices but if you want to post about what you think your number one most comfortable detector model has ever been that would be great. It could be a lousy detector in every other way, all I am looking for it what detectors feel best on your arm when held for long hours. There are no right or wrong answers - this is a personal preference thing, determined in large part by hand and forearm size. The "S" rod grip is where the grip is just part of the rod itself, not a separate element. The Post grip is a separate post attached to the rod. Lots of people call this a pistol grip, but that really is more about the shape of the grip. I have seen good pistol grips in an S rod design. There are also Post grips on S rods so it is not the S that makes for the S rod grip but the fact it is integrated into the S. The photos here make it more obvious. There is a difference simply between curved shafts and straight shafts but that is actually a separate subject so I will make a separate poll on it.
  13. Hi steve Herschbach Sir Hope you are good Sir i want to buy metal detector that can detect upto 15 feet I belong to pakistan Here the soil is mineralized Some people suggested me GPZ 7000 Some suggested the jeo hunter 3d dual pack (made in turkey) I have also searched the BR Royal Analyzer Basic which is launched recently in 2017 Sir i want the best detector thats why i need your help Pls suggest me the best detector . Waiting for your reply Sir
  14. When Minelab offered the statement that the new Equinox would obsolete single frequency VLF detectors there was a hue and cry of disbelief from a group of end users. Yet the manufacturers, even before the first Equinox was available for retail sale confirmed that statement by lowering prices. There were two aspects of the statement issued by Minelab that seems to have been missed by some end users: 1. The statement was 90% aimed at other manufacturers. 2. The statement was forward looking at the economic viability of future production of single frequency VLF’s. Now an end user may think that the Acme 4000 was the greatest relic detector ever made and cannot be displaced by an Equinox. However if the sales numbers fall to a certain point then the Acme 4000 will end up being discontinued. So even if an end user loves and is totally invested in an Acme 4000 there is no guarantee it will survive the sales onslaught of the Equinox. To those who say “hogwash” then may I ask how many new recent model BFO or T/R detectors do you see being for sale by manufacturers? Why aren’t there any? Because Technology moved on, just the same as is occurring with the Equinox. Tough time to be a product or sales manager at a competing metal detector company!
  15. Lots of good stuff here to chew on! From https://www.minelab.com/anz/go-minelabbing/treasure-talk/equinox-technologies-part-4 EQUINOX Technologies (Part 4) March 20, 2018 10:05am Minelab Electronics This is the fourth installment in a blog series introducing and explaining the technologies inside our new EQUINOX detectors… (Read Parts 1-3 here.) In Part 3 we ended with mentioning the different Multi-IQ “frequency weightings” for the different search profiles. Part 4 explains 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. If you haven’t tried EQUINOX yet – why not give it go – with Multi-IQ being fast AND accurate, those diminishing and elusive targets are running out of places to hide! (Part 5 to follow…)
  16. The World's First Smart Detector & Imaging System that can display the shape, depth and dimensions of underground metals in real time! Ideal for Deep Treasure Hunters, Archaeologists, Municipalities, Utility Companies, CSI and Law Enforcement Agencies. http://noktadetectors.com/features_invenio-metal-detector.asp
  17. So Im curious... with Makro/Nokta we saw a ton of You Tube videos on the Kruzer in various settings. Even Dilek posted on the machine on the forums before it came out. Even the AT Max we say a little here and there on the unit. Where was the early info on the Equinox? I know there was/is a "gag order" in place, and boy did they do a good job... not a word from anyone hardly! But when does the gag order lift? 1 year, 10 years Never? I'm interested in the "seasoned" testers that were able to use early models. These early thoughts to me are a real gem on what was changed, improved, altered. Any ideas?
  18. Robert Frost Two roads diverged in a yellow wood, And sorry I could not travel both And be one traveler, long I stood And looked down one as far as I could To where it bent in the undergrowth; Then took the other, as just as fair, And having perhaps the better claim, Because it was grassy and wanted wear; Though as for that the passing there Had worn them really about the same, And both that morning equally lay In leaves no step had trodden black. Oh, I kept the first for another day! Yet knowing how way leads on to way, I doubted if I should ever come back. I shall be telling this with a sigh Somewhere ages and ages hence: Two roads diverged in a wood, and I— I took the one less traveled by, And that has made all the difference. Another title for this may have been the Tale of the Equinox In reading many forum posts across the Internet there appears in many instances to be an undercurrent of anger towards the Equinox simply because Minelab produced a detector with the technology and feature set it possesses, and not a U.S. based competitor. Minelab took the road less traveled! More than a decade ago First Texas purchased Fisher Labs and also took into their employ the engineer that developed the CZ a multi-freq based platform. So right from the start they had the ingredients in house to produce an Equinox type of detector. When they began releasing their F75 and T2 series which were ergonomic, lightweight, and modern interface based detectors, a hue and cry came from CZ owners that pleaded for a CZ update with similar characteristics. Waterproofing to 3m would have just been icing on the cake! But alas it was not to be and after a while CZ owners lost faith that it would ever happen. Another U.S. manufacturer White's has also had multi-freq technology at their disposal for a very long time and instead of targeting their last multi-freq release at a sub $1K lightweight detector, they decided to go after the Minelab deep turf machines. Even in their more recent mid-priced efforts multi-freq is nowhere to be found. Garrett should at least get some credit for producing a waterproof mid-price detector because it was a milestone for the industry. But with the second generation if they were capable of producing multi-freq in the AT chassis with a reasonable premium, say $200USD more, then they would likely have had a real high selling model. But they dropped the ball also. Tesoro, well........ I like Tesoro but I don't think anyone has expected them to move the needle now for a very long time. So U.S. manufacturers have squarely squandered the opportunities for a decade or more. And now there is a Dragon in their house. And it is not the Equinox 800! As Steve H. has mentioned a couple of times with very little reaction, the Equinox 600 is a very big danger to the financial well being of many metal detector companies. Right now because of initial demand the unit is likely selling at or close to the $649USD MSRP. By this time next year I would not be surprised to see a street price of $599USD and possibly lower. $589USD or $579USD may not be out of reach. Anyone with any sales or marketing experience can go to their favorite online metal detecting seller and take a look at the offerings between $450USD and $600USD. Comparing features and performance on units in that range will be eye opening. The problem with the reaction that some companies have already taken, which is to push their former flagship models down into mid-price range, is that they then have to push their mid-price units down into entry level range which will lead to simply pushing the entry level units out of the market, or selling them at a loss. You can only sell a loss leader for so long unless you are able to up sell that customer, which you hope to retain later on(very risky). So a thinning of the herd or else value packages where, buy this model and get 2 extra coils etc is coming. But those coil packages kill profitability as accessories are where the money is. The solution is obvious and has been for over a decade, produce a NOX like detector! The Equinox exists because U.S. manufacturers sat on their hands, and if you want to be angry about it then point the anger to where it belongs. There was a vacuum in the market and Minelab filled it, simple economics 101.
  19. This has been the subject of much debate and I thought I would weigh in with a little this versus that to help offer a little guidance. I think Minelab was caught off guard by all this because the whole conversation from their perspective was supposed to be about AT Max versus Deus versus Equinox. Yet the majority of the debate is about this Minelab versus that Minelab. I guess that is a credit to Minelab but at the end of the day I am not sure they are too worried about what Minelab you buy as long as it's a Minelab The Minelab Sovereign and the Excalibur introduced the world to Broad Band Spectrum (BBS) which was Minelabs term for their first generation multifrequency detectors. The Sovereign and the Excalibur are tone based detectors with no screen and so are for people who hunt by ear. They act like very low frequency detectors and because of this are very strong on silver coins. They also do relatively well on gold targets though they are weak on the smallest gold targets. They are very well behaved detectors that handle harsh saltwater environments well, making the Excalibur perhaps the most successful underwater detector made. The BBS detectors are strongly biased against ferrous targets and better ignore ferrous than any detector I have ever used. Ferrous is almost invisible to a BBS detector. This comes at a cost however. The processing speed is very slow and combined with the strong bias against ferrous target masking is a problem with these machines. That is not to say you cannot find targets in ferrous trash. You can. It is simply an area where BBS is very weak. The next generation introduced Full Band Spectrum (FBS). The Explorer, Safari, and E-Trac further refined BBS and without getting into details the big addition was a two dimensional target id display that locates items on screen with a combination of a ferrous number and a conductive number. This dual target id combined with a screen added more refined discrimination capability to a detector already very well suited to people that hunt by ear. Anyone talking about the Explorer and silver will usually mention the great tones it makes on silver. The frequency weighting is very much in favor of low conductors and the Explorer series became famous for the ability to extract silver coins from park type scenarios i.e. turf hunting. A faster processor speed improved the situation with masking in dense targets to a degree, but the FBS machines still lag single frequency detectors a lot in this regard. The FBS detectors again are excellent at identifying and rejecting ferrous targets. The Minelab CTX 3030 introduced FBS2 which further refined things. I am being purposefully over simplistic by saying the CTX mainly added an even faster processor, color screen, and the ability to be submerged to 10 feet. FBS2 appears to be a little hotter on small gold items but the main strengths are still in silver and in ferrous rejection. The color screen added new features like target trace that allow more than one target to be displayed at once for world class discrimination capability. The BBS/FBS series have been extremely popular around the world and are to this day. However, the detectors faced competition in three main areas. They are relatively expensive detectors and they are relatively heavy detectors. And even though they can find good targets in dense trash they also leave a lot behind due to the slow recovery speeds. The Garrett AT series was revolutionary in creating detectors waterproof to ten feet that only weigh about three pounds and at a price so low it really turned the market on its ear. These detectors have been immensely successful in creating a high value combination of features at a very low price and with decent performance. This combined with top notch marketing makes the Garrett AT series very popular especially in the United States. The XP DEUS came out of left field and in Europe took the market by storm. These detectors are both extremely light in weight and extremely fast in target response and recovery speed. These two factors alone mean that a detector rally in the U.K. will be almost nothing but Deus detectors with a smattering of other machines. Deus does also focus on low conductor performance, as the recent addition of high frequency coils reveals. Remember that small thin silver items like hammered silver and cut silver coins actually respond as low conductors. Minelab saw this happening but the truth is coin and relic machines are a far distant second when it comes to profits compared to the gold machines. Any company only has so many resources and the GPZ 7000 development in particular was a major lift even for Minelab. Still, the company knew it would have to address the situation with detectors that did exactly what the Garrett AT and XP Deus did, which was target BBS and FBS where they are weakest. Price, weight, recovery speed, and low conductor sensitivty. Equinox does all this while also adding the latest twist on their multifrequency technology; Multi-IQ. The intent here as Minelab has made clear was not to replace the BBS/FBS machines but to augment them with another line that is specifically better in areas where BBS/FBS fall short. Again, weight, price, recovery speed, and I am going to add sensitivity to small low conductors to that list. I had a CTX 3030 and loved it. Yet I rarely used it. Why? My type of detecting. BBS and FBS favor people who hunt high conductors and typically favor people who hunt in mild to moderate ground. I do just the opposite. I hunt low conductors, gold specifically, and in highly mineralized ground. It is hard for people who do not hunt highly mineralized ground to understand how much it impacts detector performance, but seeing overall VLF depths cut by 50% or more is not unusual. Target id also suffers a lot in bad ground as does target masking from hot rocks and the ground itself. I know a lot of BBS/FBS users have a hard time grasping this, but in my ground there is no major benefit to BBS/FBS except for the fantastic target id capability, especially as regards ferrous rejection. Depth is easily matched or exceeded by the best single frequency detectors, which however suffer in their own way with unreliable target id. And the fact is multifrequency has always been weak on gold - not even Minelab suggests that BBS/FBS machines should be used for gold prospecting, although people can and do find gold nuggets with them. Still, you can't beat BBS and FBS for being well behaved, easy to operate, and in having top notch target id combined with best of class ferrous rejection. Arguably the worlds best machines for hunting silver in turf. Everything in designing metal detectors comes in the form of a trade. When you gain one thing you tend to lose something else. In general putting the fine details of Multi-IQ aside I think the Equinox acts more like a single frequency machine in some ways than what people are used to from BBS/FBS detectors. In particular we have the lightning fast recovery speed and extreme sensitivity to low conductors. Multi-IQ put simplistically adds the target id accuracy that single frequency machines lack in bad ground. In my opinion people coming from hot VLF detectors will take to Equinox more easily than people coming from BBS/FBS detectors. I love hot VLF detectors for what I do so Equinox is a natural fit for me. The move from the more stable well behaved BBS/FBS machines is more jarring for people I think because they are stepping into another world - my world - where they are perhaps less comfortable. People who hunt low conductors, especially in bad ground, and those who hunt non-ferrous in bad ground know that the ferrous/non-ferrous divide is an area fraught with danger. Reject too much ferrous, and you lose the non-ferrous. It appears impossible with current technology to get a clean ferrous/non-ferrous separation. I mean honestly, all I want is a detector that beeps on non-ferrous and shuts up on ferrous and does it with near 100% accuracy. This would seem simple given the difference in magnetic properties between ferrous and non-ferrous targets, but to this day flat steel, washers, hardened steel bolts and screws, bent nails, nails on end, broken square nails, etc all present problems for all metal detectors. It is a huge fuzzy area, and in the end it appears we have to make an unpleasant trade. Equinox in targeting the BBS/FBS weaknesses regarding target masking and low conductor sensitivity is making this trade. The machine steps back in a way and favors those who hunt by ear. Most of the commentary I see about target id spread and the potential limitations there fly over my head because I prefer to hunt by ear with a wide open screen in 50 tones mode for general park and beach detecting. If you are a BBS/FBS hunter this should be familiar to you and yes, you get something pretty close to familiar Minelab tones with Equinox. For field hunting (relics) or nugget hunting in dense trash I am more likely to go to a two tone type mode just due to the sheer number of targets but two tones does make a person more susceptible to ferrous squeaks tricking you than 50 tones where the nuances are more apparent. There is no right or wrong here because people seriously do tolerate this kind of stuff to a largely varying degree and so to say 50 tones is a magic bullet is just plain wrong. We all have to find the balance that works for us personally. Just remember there is a reason many Deus users tell people to stick the controller in their pocket and forget about it. Deus and Equinox favor people who hunt by ear. I apologize if this oversimplifies things but that is what many people need right now. I am leaving price and weight off the considerations below and just talking performance. BBS - only current model the Excalibur. For people who hunt by ear, great in saltwater, great on silver, very good on gold, superb ferrous rejection. Main weakness slow recovery speed, target masking. Moderate depth in highly mineralized ground on low conductors. FBS - current models Safari and E-TRAC. Basically same as BBS with marginally improved recovery speed, main addition target id screen with dual ferrous/conductive id offering very high resolution discrimination. Great on silver, superb ferrous rejection. Main weakness slow recovery speed, target masking. Moderate depth in highly mineralized ground on low conductors. FBS2 - CTX 3030. Slightly improved recovery speed, slightly improved sensitivity to small gold, color screen, target trace. World class discrimination. Great on silver, superb ferrous rejection. Main weakness slow recovery speed, target masking. Moderate depth in highly mineralized ground on low conductors. Multi-IQ - Equinox. World class recovery speed, world class sensitivity to low conductors in mineralized ground. Very good on silver in highly mineralized ground. Weaknesses are less visual target id resolution compared to BBS/FBS, weaker on silver in low to moderate soils, ferrous handling more akin to hot VLF detectors than BBS/FBS detectors. Unknown yet but may exceed or at least match BBS/FBS in saltwater environments. Again, I am purposefully oversimplifying things here on purpose. People including myself have a tendency to wander into the weeds with this stuff and get lost in the fine details. The bottom line is BBS/FBS and Multi-IQ are complementary technologies, each strongest where the other is weakest. For a certain type of user (me) Multi-IQ does indeed replace BBS/FBS. In my ground and on my targets including silver I see no benefit at all to BBS/FBS except the ferrous handling. Yet I know that is the price I have to pay to get the performance I want. On the other hand, people hunting silver in lower to moderate ground conditions have the edge with BBS/FBS and if you hate digging any ferrous at all these machines are best of class in rejecting ferrous. I hope that helps. I have to note again in closing this was never really supposed to be about this Minelab versus that Minelab but when it comes down to it Minelab is really happy to have that discussion. Equinox was specifically designed to compete with the competition, not Minelabs own detectors. Maybe a future version of Multi-IQ will give us the best of BBS/FBS and Multi-IQ in one detector but for now both offer their own strengths and weaknesses. And while Multi-IQ as currently available in Equinox is not perfect, it would be crazy to ignore the weight and price issues. They matter - they matter a lot to some people. Equinox in my opinion offers bang for the buck value that cannot be ignored, and for that reason alone it is going to be a sales juggernaut no matter where our little online debates lead us. And for you who love BBS/FBS - nobody is taking them away from you. Go detecting, be happy! Disclaimer - all the above is just my outlook and personal opinions and do not represent Minelab in any way, shape, form, or fashion. It is based on my own experience plus reports coming in from other people that I trust but should still be considered preliminary information/opinions. Nobody including me is an Equinox expert yet and no doubt its use will be refined as more people share tips and tricks.
  20. I love analogies. Maybe this one will help some people. Low recovery speeds magnify signals and fast recovery speeds truncate signals. Digital machines usually chop signals into discrete portions. A target is “grabbed” and then it is “released”. A new target cannot be “grabbed” until the last one is “released”. Imagine a conveyor belt going by with a line of wooden blocks. The blocks have anywhere from 9 to 16 sides. You are standing there blindfolded as the blocks go by. You can pick up a block and feel it for as long as you want to try and decide how many sides it has. The longer you roll it around in your hands, the better. Your chance of deciding if it is a thirteen sided block or a fourteen sided block is better if you have more time. However, you are being graded by how many blocks you identify correctly, and if you hold one too long some pass by before you can pick them up. The conveyor is passing 8 blocks per minute past you. If you have a recovery speed of 1 you hold each block one minute and you get a great “signal” on that block. But seven other blocks go by as you are taking your time identifying the one block. You increase your recovery time to three and now get 3 out of 8 blocks but have less time to hold each block. Less signal information. Still, you get them all right. Now you increase recovery time to 5 and are only missing three blocks. Your slower buddies are having a hard time keeping up now and making mistakes, misidentifying blocks, but you are doing great. You notice that people standing back are having to reach farther to grab a block and put it back. They are “going deeper” but it is costing them time. You step closer to the conveyor belt so you don’t have to reach as far, and are now a little faster by not reaching as far. You lose a little “depth” but gain some speed. You go to recovery speed seven and your arms are a blur. Your buddies all give up and stand back in awe as you pick up and put down blocks at lightning speed, and are still calling them right but you can tell you are at your limit. You finally go to 8 and still get almost all right it every now and then you have to put a block back down before you can tell what it was. You don’t have enough time, enough signal to work with. You also get to change the conveyor speed. You can swing your coil slower, and now you have more time to look at each target. That means you can lower the recovery speed and still keep up with the targets. Great for the slower workers (detectors) who have a hard time keeping up. That is a decent analogy for recovery speed and what it does for the ability of a detector to clearly examine a target versus how many targets it can process and how far it can reach. Slow detectors, slow conveyor workers, don’t have a chance. Only the fastest workers, the fastest machines, can pick up and process all the targets correctly in a short period of time. They are a rare breed. One of the biggest advantages you possess in Equinox is the lightning fast recovery speed. I see far too many people throwing that advantage away thinking a lower recovery speed gets “more depth”. No point in getting an Equinox then, just stick with the slower machine you already have. Give Equinox a real good go at the default higher recovery speeds before deciding to toss away what is perhaps the most important advantage the machine has - lightning fast recovery time coupled with accurate target id and minimal depth loss at those high speeds. That is the Equinox difference. Don’t waste it. Recovery Speed, Recovery Delay, And Reactivity
  21. The following information is from an apparent leak from a First Texas distributor meeting? The link is posted at http://www.detectorprospector.com/forum/topic/555-new-fisher-pulse-induction-multi-frequency-detectors/?p=10571 as part of the thread about upcoming Fisher products that have been circulating for a couple years. These leaks seem to jive with previous statements by Tom Mallory of First Texas. The main one of interest to the people on this forum would be a new CZX model aimed at gold prospecting. Here is the text from the posted screen shot: CZX - Fisher and Teknetics This machine is ground breaking technologyTurn on and go2 frequency - 9:1 ratioNo need to ground balance or adjust the detector to the environmentIt automatically senses the ground and makes changes accordingly.First detector birthed from this platform is a gold unit priced around $1000, but deeper than current VLF, this detector will also see through red dirt, and highly mineralized soil.From this platform other machines will develop. We intend to develop the CZX and MOSCA platforms to offer more machines in the $1000 to $2000 range than have ever been available.Target release 2016We have senior engineer Dave Johnson on this projectThe "Mosca" platform referred to is further described and apparently is aimed more at being a general purpose non-prospecting detector (coins, jewelry, relics). Again, here is the text from the posted screen shot: "Mosca" Fisher and Teknetics Waterproof up to 10' (3 meters)Wireless headphones - Waterproof loop and connectors for headphones2 frequency - 7:1 ratioHobby/Treasure Market - Great for Saltwater, Relic, CoinAuto Ground TrackingSingle Pod DesignLCD Pad, control buttons, 2 AA batteriesArm Pad in rearRetail target - $1200 - $2000Target release 2016We have dedicated engineers on this project OK, so a gold unit around $1000 that goes deeper than current VLF designs. I also have high hopes that knowing the proclivities of the engineer, Dave Johnson, that it will be relatively light and ergonomic. Dave also prefers simple and the design statements reflect that. We seriously need something that brings gold detector weights and prices back to earth and so hopefully this will be it. I have stated over and over again I would be very happy with ATX equivalent performance in a less expensive lightweight package. Garrett so far seems disinclined to make that unit but they have a year at least before it may be a moot point. The CZX would have to obsolete the White's TDI as it is aimed squarely at or below the same price point and unless it beats TDI performance would be dead on arrival. We will not have long to wait - 2016 is coming fast!
  22. This is pretty simple. Straight shaft, or some kind of curved shaft? The most common curved shaft is the S rod but there are others. Please vote in the poll so it tallies results but if you want to add commentary/particulars that is great.
  23. HI everyone. i'm student of Electrical Engineering and in last year. Our group making final year project named as "Landmines detection using Drone". So far we have completed the Drone which have a payload of 1.5kg and a "Base Station" which will get the coordinates from Drone upon mine detection using its composite GPS module. Now we are stuck with Metal detector which will be less in weight and has more detection range. Please guide us which one will be suitable for us . Either from Pulse induction or EMI... If anyone has a design then please share with me. Thanks a lot..
  24. A common misperception among those new to metal detecting is that metal detectors can identify one metal from another. How much we wish that were true. The reality is that for all practical purposes the common metal detector target id scale is based on a combination of the conductive or ferrous properties of the item multiplied by the size and shape of the item. There are two common terms in use for this scale. The Target ID or TID scale is the most generic. White's also popularized the use of Visual Discrimination Indicator or VDI numbers. You will see references to both TID and VDI numbers and both refer to the same thing. The problem when you use Google is that TID also refers to Terminal ID number, which is for credit card machines. VDI gets far better results as the preferred term and so is what I will use from now on. The VDI scale is almost always arranged the same way by common convention although in theory it can be rearranged any way you want. The common scale has ferrous items on the low end and non-ferrous items on the high end. Ferrous items are like mirror images of non-ferrous items and so the most common arrangement of the VDI scale is with small items in the middle with ferrous getting larger in one direction and non-ferrous getting larger in the other direction. The ferrous and non-ferrous ranges actually overlap in the middle. Large Non-Ferrous Medium Non-Ferrous Small Non-Ferrous Tiny Ferrous/Non-Ferrous Overlap Small Ferrous Medium Ferrous Large Ferrous We can assign a numeric range to this basic VDI scale any way we want. Many early machines went with a 0 - 100 scale, with the ferrous compressed into the low end of the scale: 100 Large Non-Ferrous 50 Medium Non-Ferrous 20 Small Non-Ferrous 5 Tiny Ferrous/Non-Ferrous Overlap 3 Small Ferrous 1 Medium Ferrous 0 Large Ferrous The idea of ferrous as negative numbers made sense due to the mirror imaging in size between ferrous and non-ferrous. A very common White's scale runs from -95 to 0 to +95 95 Large Non-Ferrous 50 Medium Non-Ferrous 15 Small Non-Ferrous 0 Tiny Ferrous/Non-Ferrous Overlap -15 Small Ferrous - 20 Medium Ferrous - 40 Large Ferrous The "positive only" 0 - 100 VDI scale seems most popular these days with other manufacturers, but the scheme varies. Two very common setups are 0-40 ferrous and 41-99 non-ferrous OR 0-10 ferrous and 11-99 non-ferrous. But as I noted you can set this up any way you want and so other scales do exist. When we look at just the non-ferrous part of the scale, what is important is how the detector "sees" the target. In very simple terms conductive targets are either very weak or very strong or somewhere in between. Small items are weak targets. Low conductive metals are weak targets. Large items are strong targets. High conductive metals are strong targets. The shape matters. Irregular shapes or thin items are weak targets. Rounded and thick items are strong targets. On a conductive scale of 0 to 100: 0 = very small targets 100 = very large targets 0 = very thin targets 100 = very thick targets 0 = very low conductive metals 100 = very high conductive metals 0 = very irregular shaped targets 100 = very rounded targets, especially is a hole in the middle Add this all up and small gold items are low on the VDI scale and large gold items high on the scale. Silver being a better conductor than gold, a silver item will read higher on the scale than the identical size and shape gold item. In general silver will read higher than gold. However, a very large gold item can read higher than a very small silver item. Chasing thin hammered silver coins in the U.K., especially the cut varieties, is not that different than hunting gold nuggets. What you rapidly figure out is the metal detector VDI scale can only get repeatable results on certain man made items that are the same every time, like a U.S. nickel or a U.S. dime. And even these signals degrade when deep in the ground or in proximity to other items under the search coil at the same time. Given all the limitations, it is a wonder we get any degree of accuracy at all with detector discrimination systems. With that, I give you a standardized White's VDI scale taken directly from the control box of my White's DFX. This -95 to 0 to +95 scale is common on many modern White's detectors. Nearly all other detectors have the same relative positioning of items just with different numeric scales, an exception of note being the Fisher CZ detectors, which use a rearranged scale. This DFX scale is helpful because it includes gold coins. The main thing I want you to focus on here is the relative positioning of items on the scale. As a detectorist operating in the United States, I always pay attention to just three things 1. where do the ferrous numbers start? 2. where does a U.S. nickel read? and 3. where does a U.S. dime read? If I know those three things, I can adjust almost instantly to any detector scale in existence, because I know how everything else reads in relation to those three points on the scale. Looking at the scale you can use gold coins as a rough guide to where large gold nuggets will read, although coins being pure gold and round will read much better than gold nuggets of the same size. It might take a one pound gold nugget to read the same as a one ounce $20 gold coin, which in turn reads very close to the U.S. silver quarter reading. On the other end, tiny gold, tiny ferrous, and salt water, being a low conductive target, all overlap. This is why if you tune out salt water on the beach, you also tune out single post gold ear rings and thin gold chains, which read like small gold nuggets. If a prospector tunes out salt alkali readings on a salt lake, there go the small gold readings. And the chart shows that if you get too aggressive in rejecting all ferrous items, good items can be lost also. When I say small it is important to note what we are really talking about is small/weak readings. A large gold item buried very deep in mineralized ground will have a very weak reading and appear as a small target to the detector. This means a very deep large items can appear just like a very small gold item and be lost for the very same reasons as those small items. Again, think weak targets and strong targets to get a better feel for how things react in the field. To sum up, gold and platinum are low conductive metals, and when also small in size read very low on the VDI scale, even dipping into the ferrous range. The foil range is the sweet spot for ear rings, thin gold chains, small womens rings, and platinum items. In general women's gold rings will read below a U.S. nickel and men's gold rings will fall above a U.S. nickel on the VDI scale. Nearly all gold nuggets found by most people are going to read nickel and lower just because nearly all gold nuggets are small. However, as this photo I made using my DFX and some gold nuggets shows, gold nuggets can read all over the place due to their shape and purity. Surprisingly, if you add silver to gold the conductivity drops as alloys are less conductive than pure metals. This makes many gold jewelry items and gold nuggets far harder to detect than would be the case were they pure gold. See this article for details on this nugget photo Some Gold Nugget VDI Numbers You can get some great spreadsheets for jewelry VDI numbers for White's and Minelab detectors here. There are no doubt many people who have read this who are just shaking their head and thinking "this is why I just dig everything". I absolutely agree, when at all possible, that is the best solution. Unfortunately it simply is not possible in some locations where trash targets outnumber the good by thousands to one. This is where knowing the VDI scale and how it works can pay off. The best book ever written on the subject of discrimination is "Taking A Closer Look At Metal Detector Discrimination" by Robert C. Brockett. It is out of print but if you find a copy grab it, assuming the topic interests you.
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