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  1. Here's a piece of an ad that showed up on my browser page while reading the forum. I sometimes miss figuring things out but this one (on the surface) seems too far out there to have me fooled, but I never really know. The one on the left is particularly bizarre. Maybe just kids toys that don't actually work but make them think they are detecting? (I could have clicked the ad and gone to the site but I'm always concerned that this will lead to me being targeted by more of their ads.)
  2. https://www.abc.net.au/news/2021-01-29/water-diviner-bob-biggs-says-he-can-divine-for-gold/13084288
  3. While this topic is hot and on our minds, I'm going to make a request. Could someone with detailed technical & engineering knowledge write up a report explaining Iron Bias at an intermediate-to-advanced user but still layman's level? The kind of description I'm requesting is one similar to what was done in Randy Horton's excellent monograph Understanding Your X-TERRA which contains an interview with Minelab scientist&engineer Dr. Laurence Stamatescu (starting on page 79) where he melds the right combination of technical info and easy to follow wording. Maybe there has already been such a writeup that I'm not aware of, but although I appreciate what has been posted here on the forum on this subject I'm still confused/confounded as to what is going on and how to best utilize it. I don't seem to be alone on that. One of my many gaps in understanding is whether or not all detectors have an effective (but fixed) iron bias setting, with only a few giving the user the option of dialing it in for best performance. Related: when iron bias on the MInelab Equinox is set to zero (in either F2 or FE), is there still some kind of iron bias occurring? Knowing how a detector works transfers over to optimizing it's use and I'd like to do more of that instead of just locking iron bias on one value for all applications and conditions (or blindly accepting factory defaults) -- what I (and apparently most users) do now based upon ignorance. (Well, I'm ignorant on this subject -- not trying to associate that with any of you. 😏)
  4. Ok folks, someone please tell me this is just a bizarre series of coincidences. On three separate occasions now I've come across a good signal out in the forest here in Virginia, usually in the pulltab range, and dig only to find a hibernating snake. How in the world is that possible? Is the metal detector actually detecting the snake or are they just over a target? I can't figure this out. Any old hands wanna chime in here?
  5. I have got up on my soapbox every year about this time to prognosticate about the coming year in metal detector technology. 2020 was an especially significant year as we lost another major player in the industry. A few years ago it was Tesoro going out of business. In 2020 we learned that White's is closing shop and being acquired by Garrett. It is unknown if Garrett will attempt to keep White's alive as a separate product line, or simply acquired the rights and technology to keep somebody else from doing so. At the moment it seems White's has gone away for good, but it is not impossible Garrett will revive the name in 2021. Whatever they decide will have a major influence on metal detecting in the future. But in the meantime we have fewer players now to speculate about. Garrett/White's - we just saw the release of the Ace Apex, a first foray into multifrequency by Garrett. The company already has a very well implemented wireless audio system, and the Apex is fully rechargeable. The White's acquisition means Garrett adds the V3i multi tech and TDI PI tech to their IP base, and this along with the half-sine patent means Garrett has a fresh shot of technology options to choose from. The White’s 24K is a superb product, now unavailable new. However, I expect an acquisition of this magnitude to take time and I'm not holding my breath on any really new product in 2021 from Garrett. At most perhaps a revival of some White's models, or releasing clones under the Garrett name. At the moment however I see Garrett as the U.S. company with the most potential for the longer term future, regardless of what happens in the near term. First Texas (Bounty Hunter, Fisher, Teknetics) - whereas Garrett seems to have a purpose, First Texas seems adrift these days. Most of the Fisher models on the website have been discontinued, or are decades old. Teknetics as a brand seems nearly dead, focused on factory direct sales. Basic advances like in-built rechargeable battery systems, wireless headphones, and over the internet updates - all go ignored at the company. The only news is a new line of pulse induction detectors, but as the lack of interest from users on the internet shows, most people are not screaming for First Texas to bring a PI to market. Everyone wants to hear about a major response to new machines like the Equinox, but so far it's crickets from First Texas. The final production Impulse AQ will hit the market in the first half of the year, but I expect it to have almost no impact on the overall detecting world, or even the beach detecting world for that matter. People will still choose VLF over PI for beach detecting by huge margins, so the Impulse AQ has a shot at being nothing more than a niche detector in a niche detecting market. The Gold version has potential to crack open the gold prospecting market that Minelab currently dominates, but it is going to have to have a very attractive price/performance ratio if it hopes to make Minelab users consider a new brand. For many gold prospectors Minelab currently is the only choice in detectors. Hopefully there is more going on at First Texas than PI, because they are sliding into irrelevance in high end VLF. It seems more models keep slipping into the Bounty Hunter lineup, and if nothing changes someday the Teknetics and even Fisher lines may be retired. Or the Fisher line could be boosted with new high end machines to become the high tech alternative to Bounty Hunter. That was the original plan buying this old name in detecting, and 2021 will probably determine what happens for the Fisher brand in the future. Revival... or the next slow death? Minelab - on a roll still, with the new GPX 6000 due out this spring. When it comes to cutting edge technology, Minelab remains the company to watch. There is no doubt a replacement for the CTX 3030 in the works, but there are no solid hints at when it may arrive. I am guessing 2022 since the last two rollouts were for coin detectors (Equinox and Vanquish). Minelab tends to address areas in a round robin fashion, and I believe 2021 will preferentially freshen the gold prospecting lineup. Nokta/Makro - the easy picking low hanging fruit of single frequency VLF has been fully exploited at Nokta/Makro, and it remains now to see if they can make the move up to higher tech product like simultaneous multifrequency and ground balancing pulse induction. The rapid pace of new product releases has stalled out as further advances will be more difficult. Historically NM has used their Christmas card to hint at new releases, and this year they took a pass on that. I'm hopeful for 2021 but certainly not holding my breath, as it may be fall at earliest before we hear more. Tarsacci - a new 12" coil for the MDT is in the works, and a possible change to the battery door design in future versions. XP - still largely a one-trick pony with the DEUS, and the ORX, which is really just a subset of the DEUS. Will we ever see multifrequency or PI from XP? All is quiet now with the news over ORX run it's course, and right now there are no hints of anything new from XP for 2021. Just random blatherings from an industry old-timer, worth every penny paid. I'm pretty well set for detectors these days, with only the grudge match between the Minelab GPX 6000 and Fisher Impulse Gold having any interest for me personally. I have to put my money on Minelab when it comes to cutting edge tech, but I do hope the Impulse Gold is good enough and low priced enough to shake things up.
  6. Hi Folks, Thought I would start a thread showing my first attempt at an analog detector, I've been working in the electronics field for many years mostly in the analog/rf area. Hope everyone enjoys the process, and any input or suggestions would be appreciated. I'll try and post as I go along, but this is my after hours hobby, so updates may come every few weeks. I apologize if this goes overboard on the images. So here goes..... Here is the overall unit, the display will tip up and turn on. Closeup of the display Display tipped up, it will show RSSI across the top, and material ID in the center and across the bottom. Control Panel, has gain hi lo, discrimination on off, coil balance, threshold, volume, phone jack, and on off with lo bat indicator. Coil Actual board and display turned on and balanced, I'm sorry for the vertical image I couldn't straighten it up, the coil is under the paper, it's a hand wound 3" OD test coil. Note that this board has only three adjustments and the one in the above renderings has four, this one has no threshold adjust. 1957 silver quarter Gold chain and cross. Aluminum pull tab. Coke bottle cap. Clad quarter. My steel cutters. I'm getting parts in to start putting the new one together, hopefully my updates to the circuit will work out. We have a saying, "may have to shoot the engineer to finish the project", it feels like every other day I come up with another improvement :), anyway I hope you guys enjoy this, I'll post as I go along. -Sun-Boy
  7. Is this the future of detecting? I think so. Take a set of data points and process them (just as we do with our brains) and voila! It doesn't have to be magic when you have good science to make it repeatable. Watch out missed nuggets! Currently, a type of software based on a machine-learning algorithm called deep learning has been shown to be effective at removing the blurriness or noise in images. These algorithms can be visualized as consisting of many interconnected layers or processing steps that take in a low-resolution input image and generate a high-resolution output image. https://scienceblog.com/520757/smart-algorithm-cleans-up-images-by-searching-for-clues-buried-in-noise/?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+scienceblogrssfeed+(ScienceBlog.com)
  8. Been meaning to do this test for a while. I used 3 machines that have VDI. Multi Kruzer, AT Pro and Gold Racer. Test was done as follows: Plastic bin 5" high with masking materials above and targets placed directly below. 3 different masks were used: 1 rust, 2 magnetite, 3 crushed coal. All 3 placed into baggies to avoid miserable cleanup after and bags were layed flat with material distributed as even as possible within the bag. All machines set at 80% gain/sensitivity. the Multi Kruzer had the Super Fly coil which I kept on as it is most likely similar to the Simplex 11" and Amphibio stock 11" in performance and separation. AT Pro had stock 8 1/2 x 11 dd and the Gold Racer had the stock 5 1/2 x 10. The Multi Kruzer was run in 3 tone mode, AT Pro in Zero mode, and the Gold Racer in disc 1 with imask 1. I indicated "- -" where there was no ID on display but often especially on the Multi Kruzer there was clear audio of the object below. Targets were: Beaver Tail, US Nickel, 14k Gold Wedding Band, Square Tab, Pull Ring, Copper Penny, Silver Dime and Silver Quarter. This test is much more extreme than what you would typically run into in actual occurances but gives an idea on how machines respond. The masked materials gave little or no audio response but the mineral meters on the Kruzer and Racer were really high. This is important when out in the real world detecting to pay attention to the mineral meter if your machine has it then double check those targets as possibly being of value. Don't move on if you hear an iron grunt. Be nice to see similar tests with an Apex, Nox and Vanquish line up.
  9. We all have seen many videos comparing metal detectors , changing the coils, frequencies and all kind of settings so they can maximize the capabilities of the "machines"! But what about the same machines abilities to detect larger targets like a 20x20 cm or 40x30cm on greater depths?? Am in the only one Qurious about it 🤪 Have someone seen something about it??
  10. Have you modded a detector or a coil over the years to make it perform better than the manufacturer intended? Did you get good results? I just did a search on this forum and found 168 hits for modded. What is your favorite mod?
  11. Anfibio is rated waterproof to 16'. Tarsacci is rated to 30 min underwater. Both ip68 why the difference. I can't find what the Equinox rating is.
  12. I've been trying to make a PI detector as a learning exercise in another forum(Geotech). Asked the question below but haven't got a reply. Maybe someone here could answer the question. Nugget sizing info: We are often asked how many pieces per gram or ounce. It is very hard to predict how many pieces there are per gram or ounce as the # of nuggets by weight varies quite a bit per batch. But in general you can expect around 1-2 pieces of gold for 4 mesh, 2-4 pieces of 6 mesh per gram, 7-12 pieces of 8 mesh per gram and around 15-20 per gram for 10 mesh. You can expect many more pieces for smaller 12 (around 20-25), 14-16 (around 30-50 or more) pieces and hundreds for fine gold. Every batch is very different and each piece of gold is natural and of course therefore unique. Some may be flat and light or rounded and very dense (heavy). How small a nugget can a good PI detect? What mesh size would make good test targets for smaller nuggets? 8 mesh, 10 mesh, both or other? Any guess on typical TC for 8 or 10 mesh nuggets?
  13. This is a nice concept. If works I can see a lot of interest.
  14. Hey folks, new to the forum here. I am working and playing in the state of Alaska, and live in a decent gold bearing area, but it’s mostly flour gold from glacial dust.... geologically speaking it’s pretty young soil with lower levels of mineralization (I was told). The area was never thoroughly mined, because of the difficulties encountered extracting this fine stuff with old methods. Anyway, I have been picking some old-timer’s brains on how to get started, and he suggested this method for this fine stuff.... he liked to locate the mineralization zones with a detector, then dredge or sluice that. That way he would only process the more concentrated material. There are the occasional nuggets, but very scarce compared to the flour. is this a realistic method for doing a little weekend prospecting? I have been looking into detectors (the last one I had was 15 or 18 years ago and it was a very basic bounty hunter great for a kid, but....) seemingly most detectors are trying to tune out the mineralization, and I am searching for it. I was looking at the gold monster 1000, and equinox, but can’t decide if their advanced discrimination would help or hinder my goals. Any thoughts on this technique, and what machines to consider to achieve the goal? Of course I’d like something that could treasure hunt, and do everything else great too, but I know that’s not usually how this stuff works. Thanks for your time and patience. In the meantime I am going to be educating myself on the forum. Trying to soak up all this knowledge.
  15. I just had a pacemaker installed and I’m having trouble finding info on using my metal detectors with it. Just wondering how the detector batteries and EMI will affect my pacemaker. Maybe the only thing I’ll have to worry about is whether it will implode if I swing across a really big nugget? 😳 Hopefully I can keep detecting with no problems from the pacemaker or my heart! Thanks for any input. P. S. I understand if anyone is hesitant to answer because of liability issues. That’s one reason I’m having trouble getting info including from Minelab. Can’t blame anyone for that. Just general info or experiences from anyone that has a pacemaker would help. My doctor has a bad “bedside manner”. The one time I met with him before he slapped it in me was frustrating. He had a standard response to my questions. “Get it or you die”. He is a highly skilled and highly recommended jerk. Maybe I can get some answers on my follow up app’t but not counting on it.
  16. Given that the latest crop of detectors can be updated with new features simply by downloading software updates, how long will it be until manufacturers offer a cheap base model with pay as you go additional features and capabilities. Want more tone options, prospecting ability, custom frequencies, simply pay a small fee and download to your detector. On the same token have to ability to remove unused or unwanted features to de-clutter your detector, and with the ability to load them up again at a later date as needed. This would give the ability for a beginner to grow with their simplified base detector, adding new features as experience is gained and as budget allows, whilst still maintaining a budget initial purchase price. We also often talk about detectors being too overwhelming or complicated to learn for newcomers, so sometimes less is more. The downside for manufacturers is that it would do away with multiple models of detectors, often earmarked by minimal incremental changes to justify producing a new or improved detector. Good for the consumer, maybe not so much for profit margins. In a way it is already happening with detectors like the XP Deus, with constant updates to extend the lifespan of the platform, though hardly a budget detector and the updates are actually free. Any extra costs/profits are made via accessory coils and other add-ons like pinpointers vs charging for added features alone (some new features necessitate the purchase of new accessory coils to be activated). You do have to appreciate that the Deus's lifespan amazingly started out in 2009, proof that a single platform can last the test of time and still be relevant even today. Imagine a base version of an improved Simplex with added hardware/software ability to run multi-frequency and/or individual frequencies, then being able to unlock MF ability down the track as budget allows. It is not always the case the one can afford the initial cost of a fully loaded detector out of the box, nor want to purchase multiple detectors to gain added features and performance. Silly idea or does it have some merit?
  17. Metal detecting has a lot of jargon that makes little sense to beginners. I’ve thought about starting a list on this website, but the fact is it’s been done in quite a few places already. While I still might put one together myself, for now here is a link that can give you all the definitions anyone might need. Metal Detector Terms & Definitions via Google Tesoro put out a great catalog in 2010 that included a lot of extra information, including a glossary starting on page 58. You can download it for free here.
  18. So for you experts on EMI interference. Does EMI effect the powerhead?, coil? or both???? Thanks.
  19. I did a quick recording of items I had going from a small nickel silver bead through a screw cap. Total of 20 items 6" away in both all metal mode and discrim mode with disc at min. It is interesting how you can actually see the different sounds and how they have unique patterns. I plan on redoing the test when I can set up outside. There is a lot of emi here and my audio setup was not tuned so I couldn't hear the threshold through the computer even though it was pretty loud on the detector. The audio was also recorded really hot which I will correct next time. Wonder if digital machines have just flat signals with no variation other than tone and volume? I can't record my Garrett as it has a proprietary audio jack.
  20. Is there now marketed or has there ever been available a detector which inverts the audio volume scale? Many applications produce better finds from the weaker signals, either because those items are smaller (e.g. micro jewelry) or deeper (e.g. old coins and nuggets). Having to listen through the din of trash to hear the weak signals for most detectors is mentally fatiguing. I wouldn't be surprised if this is/was possible with analog electronics, but seems like a task that digital processing could handle easily(?).
  21. I posted this in the vanquish thread but it’s buried fairly deep so I’m asking here too, about the vanquish, it’s multi iq technology rooted in VLF technology or is it something different all together? I was under the impression this is a multi frequency VLF detector that basically samples multiple VLF frequencies simultaneously to better I D targets and while the way it makes this possible is unique the signal would have the same limitation in heavily mineralized soil same as any VLF detector?
  22. How many guys would like JUST A BLING BEEPA. Designed completely for recovering jewellery. Having a lower range and medium so you can just get bling with a bit of rubbish included. Come on their from Nokta Makro you guys can do it.
  23. Hello All, I am new to metal detecting and looking for some advice. Metal detecting is something I've always wanted to pursue as a hobby, but just never really committed to making the investment. I have a few detectors in mind Minelab Equinox 800 or 600 and Garrett GTI 2500 also open to suggestions but those three seems like decent choices for intermediate. My question is how deep can a standard metal detector detect? There's a bit of backstory here but as a kid, I watched the movie Encino Man. For those unfamiliar the movie is about two teenage friends digging a hole in their backyard for a swimming pool. Hilarity ensues when they unearth an ice-age caveman the rest of the movie is a little fuzzy, but they acclimate their new friend to the modern world. Anyway, after watching this movie I convinced my mom to let us dig a giant hole in the backyard! For some reason she agreed. Probably because it kept us busy and out of the house. So flash forward a bit we have a decent sized hole dug in my backyard. Keep in mind I'm 9-10yrs old (so things seem much larger) but as I remember it the hole was at least 8ft x 5ft and probably 3-4ft deep. This was how I spent my summer vacation, everyday I would go outside and just dig! Then, one morning I hit something! Excited, I ran into the house to inform my mom. What I hit was the side of a metal trashcan. The sort of trashcan Oscar the Grouch lived in on Sesame Street. The can was buried sideways and I brushed away enough dirt to tell it was trashcan but the can was still completely buried. My mom freaked out and forced us to fill the hole (whatever was buried that deep was not meant to be dug up!) After 25yrs the house is now mine and the thought of what could be buried there still intrigues me (hundreds of gold bars perhaps 🤔). The home was constructed in 1940, but built on the property of another home which was constructed much earlier probably 1910s. The older home has been destroyed for years and was demolished to built 8 townhouses/condos. However, the old lady who lived there had been in the house since birth and died at age 98. The townhouses/condos were built in 2007 which suggest a 1910 or earlier date for that home. The old woman did tell us about the area when before all the countless other homes were here. How you could see in any direction for miles. Now you need a drone for that and its nothing but developed land for 50-60 miles in all directions. If I had to guess a date for the trash can 1930s era would seem to align well. The short version, there's a metal trashcan in my backyard that I would like to relocate and excavate. However, I am not sure how deep the object actually is at most I would guess its 3ft to maybe 3.5ft. Could a metal detector locate a large object at this depth? I've been searching online for an answer to this question but cannot find any conclusive information. From what I can gather the detect-ability of an object varies considerable and seems based on the objects size. Most coins, for example, are fairly small and anything beyond 30cm (1ft) is probably on the edge of not registering a signal? However, if the object is larger the detectable depth will increase? So if you're searching for a pirate style treasure chest it could be buried much deeper and still be detected.
  24. I know there's already a bunch of stuff written on iron masking. But there might be some new readers that could benefit. Over on Monte's forum I started a discussion on iron masking didn't get a lot of response but Monte did write some very informative responses if you want to visit the topic on his site it's under the relic/old site hunting section. Here's the video. Would love any additional comments on the subject if anyone would like to interject. I'm no expert and certainly don't know everything about every metal detector out there so I'm open to any constructive criticism or comments.
  25. I am a big fan of the White's SignaGraph display. A version 1.0 was originally developed for the Eagle Spectrum. The Eagle Spectrum underwent a complete hardware revamp, and was renamed the Spectrum XLT. A more refined version 1.1 of the software was matched up in the XLT with a much better LCD display. The SignaGraph was also used on the DFX, and was largely the same as on the XLT, with the addition of multifrequency options. The SignaGraph was later greatly enhanced on the V models (Vision, V3, V3i, VX3) and renamed the SpectraGraph. The genius of the SignaGraph/SpectraGraph is the ability to display multiple target id numbers at the same time, and even to choose how the target id number is determined. Here is the SignaGraph explained by its designer, engineer Mark Rowan. More details can be gleaned from the White's XLT User Guide. Spectrum XLT Engineering Note The SignaGraph™ "Phase Spectrum Analyzer" by Mark Rowan Some time ago, I had a conversation with an avid treasure hunter whose instrument of choice was White's Eagle II SL 90. He described to me a technique with which he could discern pull tabs from rings, nickels, and other desirable targets by listening for some subtlety in the audio response. Then he asked me, "If I can do this, why can't you program the Eagle's microprocessor to do it?" My response was, "If you can do it yourself, why would you want the microprocessor to do it for you?" I mention this as a means of illustrating what I consider to be the metal detector designer's fundamental dilemma, which is, as Prince Hamlet might have phrased it, "To beep or not to beep". More specifically, if you're faced with a target at some depth in badly mineralized ground and the detector has a hard time getting a solid reading on it, what do you do? If you design your detector to ignore the target, and then someone comes along with their El Cheapo brand detector and digs the target, which just happens to be a $10 gold piece -- you're in big trouble. If, on the other hand, your customers find that they're spending most of their time chiseling through eight inches of hardpan and finding bent nails and wads of aluminum foil, you're not much better off. The point I was trying to make with the gentleman who had devised the clever pull tab discriminating scheme was, that if you put too much of that kind of "intelligence" into your metal detector, there are always going to be those targets that you miss because the machine got fooled. Which brings me, of course, to the newest White's model, the Spectrum XLT. The Spectrum XLT has all of the features, performance, and flexibility of previous members of the Eagle series, plus a new display which makes the instrument remarkably easy to use. It also makes use of a new way of displaying information about targets -- the "SignaGraph™ or "Phase Spectrum Analyzer" -- which shows the operator everything that we currently know how to display about the characteristics of metallic objects in the ground. In this way, we have gone a long way towards addressing the dilemma I mentioned earlier. The Spectrum XLT is a very "smart" detector, but it is also an "honest" one. Having done the best it can to determine the probable identity of a target, the Spectrum XLT gives you all of the information you need to make your own decision (human beings are, despite what you might have heard, still a whole lot smarter than computers) to dig, or not to dig. Before I begin to describe in some detail what the SignaGraph™ is and how it works, I should emphasize that you don't need to know how it works in order to use it effectively, and that the best way to learn how to use it.... is in the field. In a very short time you will begin to recognize certain display patterns as being characteristic of certain types of targets. I should also point out that even if you ignore the SignaGraph™ altogether, this instrument still has the audio discriminator, V.D.I. number, that its predecessors had, plus the icons, and some significant improvements in terms of weight, physical size, and ease of operation. White's SignaGraph display For many years, White's has built detectors which identify targets based on a V.D.I. number (V.D.I. stands for Visual Discrimination Indicator) which characterizes metallic objects according to their size, shape, and composition. The V.D.I. scale on the Spectrum XLT runs from -95 to +95. Large positive numbers typically indicate objects which are good electrical conductors; for example, silver dollars will come in at 92. Smaller positive numbers usually indicate objects which, because of their size, shape, or composition, are not as conductive; nickels will read about 20 and aluminum foil may come in near 5. Large negative numbers are typical of targets which are readily magnetized, but which conduct electricity poorly or not at all. Some sands or soils which have a high concentration of ferromagnetic minerals may read -93. Metals containing iron have both magnetic and conductive properties, which causes them to spread over a wide area of the scale, although most typically iron objects will fall in the range -30 to -75. The V.D.I. reading is an excellent way to determine the identity of most commonly occurring targets, although I might mention in passing that the only 100% reliable discriminator is called a shovel. However, as a famous metal detector engineer once said, "Life is grossly unfair" (actually, there is no such thing as a famous metal detector engineer, and life really is fair, it just doesn't want anybody to know). For one thing, the signal which a detector receives back from even moderately mineralized ground is typically much stronger than the signal it receives from the targets buried in it. This makes determining an accurate V.D.I. number for a target at any substantial depth a very challenging business indeed. Furthermore, some targets will cause an abrupt change in V.D.I. response during the course of a single pass under the loop; the most notorious of these are the dreaded bottlecap and the dreaded small piece of foil near the surface in bad ground. Enter, as they say, the Spectrum XLT. The SignaGraph™ is very similar in some respects to the familiar analog V.D.I. meter. The display is calibrated from left to right in V.D.I. units, from -95 to +95. When the loop is passed over a target, a V.D.I. determination is made, and a vertical bar is placed at the appropriate place on the scale; near the right end of the scale, say, for a reading of 78. So far, this is just what an analog V.D.I. meter would do. At this point, the similarity ends. An analog meter can indicate only one value at a time; with the SignaGraph™, up to 30 readings can be displayed simultaneously. Also, the vertical height of the bars in the display has significance; the height can either be used to indicate signal strength or a running total of the number of readings at that point on the scale ( the operator may choose which of these two indications is to be used). The advantage of this type of display format becomes evident when the loop is passed over a bottlecap or some other flat, thin iron object. Although the instrument may respond with a loud, clear audio output, and the V.D.I. readout may register a value near the upper end, the SignaGraph™ will tend to "smear out"; numerous segments will appear throughout the display, many or most of them in the negative (typically iron) range. Try the same things with a coin, and you won't see the "smear"; typically you will see 1-3 bars grouped closely together near the top end of the scale. If any smearing does occur, as it might on a deep coin in bad ground, the more accurate readings will stand taller in the display and will tend to persist from sweep to sweep. Another unique advantage of the Spectrum XLT is the ability to make use of information gathered during the course of multiple sweeps of the loop. For years, clever detectorists have realized that by passing the loop over the target repeatedly and mentally keeping track of the range over which readings appear, and the most frequently occurring numbers within that range, they can achieve the highest possible accuracy on really tough targets. The Spectrum XLT performs this operation automatically. The standard mode of operation is the so-called "Graph Averaging" mode, in which a continuous count is kept of the number of readings that fall into a particular slot in the graph. This might also be a good time to mention that more than one V.D.I. determination is made during the course of a sweep; sometimes as many as 6 or 8 readings will be taken during a single pass, so it only takes a couple of sweeps for the effect of averaging to become significant. What you will see in the field will be a single bar on the display which will "grow" until it stands out prominently above the other bars on the display. Although it is not necessary to adjust them, there are a number of controls that allow you to customize the way that the graph is displayed. It can be set up to clear itself on each sweep of the loop, if you find that too much information is persisting in the display for too long. Or, you can configure it to let the vertical bars fade slowly out of view. Even the rate at which this fading takes place is adjustable. If you don't want to be bothered with any of that, then don't be. The factory preset settings should work just fine for almost anyone. For those of you who want to know an explanation of Accumulate, Average, and Fade, one is included in this Guide. If all of this sounds confusing or mysterious to you, allow me to put your mind at ease. The Spectrum XLT is one of the simplest-to-operate detectors you will ever use. I shall describe just how and why it is so easy to use momentarily; but before I finish talking about the SignaGraph™, I want to say it one more time-- you don't need to be a Nobel Prize candidate to figure out what the display is telling you. The usual response from somebody seeing it for the first time is something like: "Okay, I get it now. Now leave me alone and let me hunt!" What is it that makes the Spectrum XLT so easy to use? The key is something that is known in the software business as a "menu-driven interface". To implement that, we have used what is known in the display business as "A True Graphics Display". What all of this means to you, the user, is that all of the controls and options are listed clearly in plain English on the display. A flashing arrow appears on the screen next to one of those options; you can move the arrow up or down with the two "arrow" keys on the 5-key touchpad. When the arrow is next to the control you are interested in, you push the ENTER key. That is everything you need to know to run this machine. If you are like me and you hate reading instruction manuals, I believe I can safely guarantee that you will be able to operate the Spectrum XLT successfully your first time out without ever having to open the cover -- although the manual should be extremely helpful if you want to fine-tune the performance of your detector by adjusting any or all of a rather lengthy list of professional options. Incidentally, another name for this method of running a machine is the "point-and-shoot" method; you point at what you want, then "shoot" with the ENTER key to make it happen. Finally, for those in a hurry, there are a number of "shortcuts" designed to make accessing commonly used features as fast as possible. What makes the Spectrum XLT even easier to use are the factory preset programs (like those in previous Eagles) which you can load with just a few simple keystrokes, following the prompts in the display. These programs configure the machine automatically so that the beginner or casual treasure hunter can expect a great deal of success over a broad range of conditions. Any attempt on my part to detail all of the advanced features and controls which the Spectrum XLT has to offer would probably leave me with blisters on both of my typing fingers. Suffice it to say that all of the features we have had in previous state-of-the-art detectors are here in this one, plus several new ones. Most of the features are there because somebody asked for them -- the moral of the story being, keep those cards and letters coming, and we will continue trying our best to give you the kind of detector you really want. Mark Rowan was a Senior Engineer for White's Electronics, Inc. Mark holds degrees in General Science, and Electronics Engineering Technology, and is a graduate of the University of Oregon. His background includes satellite communications and RF test and measurement instrumentation. White's SignaGraph examples from Spectrum XLT manual
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