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  • Steve Herschbach
    These are reviews on metal detecting and prospecting equipment I have personally used over the years. In the last 50 years I have used a lot of metal detectors and prospecting gear! A lot of items are not made any longer but may be found used. In each instance my goal is to provide details and commentary not found anywhere else.
    For more user reviews of metal detectors visit the new Metal Detector Database. Do not miss Steve's Guide to Gold Nugget Detectors for honest opinions on gold nugget detectors updated on a regular basis. Visit the Detector Prospector Forums for expert advice. User Guides & Catalogs here.

    Fisher CZ Models - Some old favorites. Fisher CZX - Speculative new detector model.... Fisher F19 - General purpose VLF detector with prospecting mode. Fisher F75 - Flagship VLF model with prospecting mode. Fisher Gold Bug 2 - Dedicated VLF prospecting detector, extremely hot on small gold. Fisher Gold Bug Pro - Excellent value general purpose VLF prospecting detector. Fisher Manta - New pulse induction beach detector in the works at First Texas. Garrett AT Gold - Excellent value waterproof VLF prospecting detector. Garrett ATX - High performance pulse induction beach and prospecting detector. Garrett Infinium LS - Pulse induction beach and prospecting detector. Minelab Equinox 800 - General purpose detector with prospecting mode. Minelab Eureka Gold - Dedicated VLF prospecting detector, three selectable frequencies. Minelab Gold Monster 1000 - Dedicated VLF prospecting detector, extremely hot on small gold. Minelab GP 3000 - High performance pulse induction prospecting detector. Minelab GPX 4500 - High performance pulse induction prospecting detector. Minelab GPX 5000 - High performance pulse induction prospecting detector. Minelab GPZ 7000 - New high performance professional prospecting detector. Minelab SDC 2300 - Pulse induction prospecting detector, extremely hot on small gold. Minelab X-Terra 705 Gold - General purpose detector with prospecting mode. Nokta/Makro AU Gold Finder - Dedicated VLF prospecting detector, extremely hot on small gold. Nokta/Makro FORS Gold - General purpose VLF detector with prospecting mode. Nokta/Makro FORS Gold Plus - Excellent value VLF prospecting detector. Nokta/Makro Gold Kruzer - General purpose waterproof gold prospecting detector. Nokta/Makro Gold Racer - General purpose gold prospecting detector. Nokta/Makro Impact - Flagship VLF detector with prospecting mode. Nokta/Makro Racer - General purpose detector with prospecting mode. Teknetics T2 - Flagship VLF detector with prospecting mode. Tesoro Lobo SuperTRAQ - General purpose VLF prospecting detector. White's GMT - Dedicated VLF prospecting detector, very hot on small gold. White's GMZ - Dedicated VLF prospecting detector, hot on small gold. White's Goldmaster 24K - Dedicated VLF prospecting detector, extremely hot on small gold. White's MXT - General purpose VLF detector with prospecting mode. White's MX Sport - General purpose waterproof VLF detector with prospecting mode. White's TDI - Pulse induction beach and prospecting detector. White's V3i - Flagship VLF model with prospecting mode. XP DEUS V5 - Flagship VLF model with prospecting mode. XP ORX - New model from XP with an emphasis on gold prospecting. Comparison Reviews
    Garrett ATX vs Minelab GPX 5000 Waterproof Pulse Induction Detectors Compared For more user reviews of metal detectors visit the new Metal Detector Database.
     
  • Steve Herschbach
    Welcome to my free "book" about metal detecting and gold prospecting. Each chapter is a "how to" or explanatory guide, on metal detecting and gold prospecting themes. Many were written in response to questions asked on this websites forum. Each article focuses on a single subject, and they are meant to be relatively short, but to also cover the topic well. In many cases you will not find more in-depth coverage of any of these topics anywhere else. The answers were created expressly to eliminate having to answer common questions repeatedly, creating this reference for use in future threads. There is information both for beginners, and advanced topics for the pros.
    All articles are copyrighted, and may not be duplicated in any form without my express permission.
    Steve Herschbach

    Metal Detecting
    Steve's Guide to Headphones for Metal Detecting Steve’s Guide to How Deep Metal Detectors Can Go Steve’s Guide to VLF Metal Detectors and “More Depth” Steve’s Guide to Testing Metal Detectors Steve's Guide to Metal Detector "Air Tests" Steve's Guide to Metal Detector Search Coil Compatibility Steve's Guide to VLF Concentric vs DD Search Coils Steve's Guide to "Search Coils Are Not Antenna" Steve's Guide to Variations in Coil Performance Steve’s Guide to Detecting Depth Vs Coil Size and Shape Steve’s Guide to Metal Detector Sensitivity Steve's Guide to Threshold Autotune, SAT & V/SAT Steve's Guide To Why GB Numbers Do Not Indicate Mineralization Levels Steve's Guide to Metal Detector Mixed Modes Steve's Guide to Metal Detectors with Reliable Target ID Numbers Steve's Guide to the Best Target IDs For Rings Steve's Guide to Detecting Gold Jewelry Versus Aluminum Steve’s Guide to Why Detecting Thin Gold Chains Is Difficult Steve's Guide to Detecting Tiny Gold Jewelry In Saltwater Steve's Guide to Small Item Testing "The BIC Pen Test" Steve's Guide to Testing Weak Gold Targets & Ground or Salt Settings Steve's Guide to Selectable Frequency & Multifrequency Metal Detectors Steve's Guide to Why Target ID is About Size, Not Type of Metal Steve’s Guide to Metal Detector Discrimination Basics Steve’s Guide to Recovery Speed Steve’s Guide to Target ID Normalization Steve's Guide to Target Masking Differences Euro vs U.S. Steve’s Guide to Why Weak Non-Ferrous Targets Read As Ferrous Steve's Guide to Why Some Ferrous Reads Non-Ferrous Steve’s Guide to Iron Bias (Bottle Cap Reject) Steve's Guide to Waterproof VLF Metal Detectors Steve's Guide to Beach Detecting For Gold Prospectors Steve’s Guide To Why Detecting Tiny Gold In A Bottle Is Difficult Steve's Guide to VLF vs PI Depth Difference Steve's Guide to Ground Balance As A Filter
    Steve's Guide to Multifrequency Ground Balance Steve's Guide to Pulse Induction Ground Balance Steve's Guide to Pulse Induction Discrimination Steve's Guide to Ground Balancing PI and "The Hole" Steve’s Guide To More About The PI “Hole” Steve's Guide to Long Range Locators (LRLs) Steve's Guide to the Fisher CZ Series Metal Detectors Steve's Guide to Fisher Gold Bug Models Steve's Guide to The F75 Ferrous Tone Quirk Steve's Guide to Minelab BBS, FBS, FBS2, and Multi-IQ Steve's Guide to Minelab E-trac, CTX 3030, Excalibur, and Equinox Steve's Guide to Differences Between Minelab SD, GP, & GPX Steve's Guide to Minelab GPX Timings Steve's Guide to Tuning the Minelab GPX 5000 Steve's Guide to Insanely Hot Settings For The GPZ 7000 Steve's Guide to Ground Tracking As A Filter Steve's Guide to White's Goldmaster Models Steve's Guide to White's SignaGraph Display Steve's Guide to White's Electronics GMT versus MXT Steve's Guide to White's TDI Coin Settings Steve's Guide to Rebuilding The White's GMT Steve's Guide to Some Nugget Detectors of Note Metal Detector Database with User Reviews Prospecting
    Steve's Guide to How to Pan for Gold Steve's Guide to Suction Gold Dredges Steve's Guide to Where To Prospect For Gold Steve’s Guide to Getting A Mining Job In Alaska Steve’s Guide to Metal Detecting for Gold Nuggets Steve's Guide to Gold Nugget Detectors Steve's Guide to a Brief History of Gold Nugget Detectors Steve's Guide to Gold Nugget Target ID Numbers Steve’s Guide to Glaciers & Gold Steve’s Guide To Detecting Gold In Quartz Rock & Mine Dumps Steve's Guide to Finding Gold Veins With A Metal Detector Steve’s Guide to Nugget Detecting Kits Gold Prospecting Research Material For Alaska General
    Steve's Guide to Successful Rock Tumbling Metal Detecting & Prospecting Library Catalogs, Brochures, User Guides, & Owner's Manuals Thread Hall of Fame
    Nail Board Tests & Sensitivity
  • Steve Herschbach
    This is my latest "Nugget Detector Guide", now published for over twenty years, updated January 2024 with some of the latest model information. Each model has a short description, followed by a very PERSONAL OPINION. Copyright 2002-2024 Herschbach Enterprises - Please do not reuse or repost without my express permission.
    This is offered as a simple guide for those wanting a comparison of the various nugget detectors available new with warranty, along with some kind of real opinion about them. That's all it is, folks, so take it or leave it for what it is worth. It's just that listing specs is of little help to people, and so I take my best stab at providing some guidance for those newer to detecting. These are only my opinions based on my experience with various detectors over the years. While I do have a lot of experience, I must throw in the caveat that I have not used all detectors under all conditions. What may be considered a good detector at one location may not be so good at another location due to differences in ground mineralization and the gold itself. Detector performance is site specific and so your mileage may vary. Never forget that when reading comparisons on the internet.
    Although many detectors sold today can potentially find gold nuggets, I've chosen to only list current models from major manufacturers that are sold and marketed primarily as prospecting detectors or that at least have a specific prospecting mode. I no longer list general purpose VLF detectors running under 18 kHz because they are too common and that being the case they offer nothing special to the potential gold prospector. If you are interested in other general purpose detectors that might make good prospecting machine but are not listed here, look at my more comprehensive reviews list. Many discontinued prospecting detectors are also listed there.

    Various popular VLF gold nugget prospecting metal detectors
    Please, if you own one of these detectors, and I call it like I see it, don't take offense. Any nugget detector made will find gold in capable hands, and the owner is far more important than the detector model. I'll put a good operator with almost any detector on this list up against a novice with whatever is deemed "best" and bet on the experienced operator every time. The person using the detector finds the gold. The detector is actually one of the less important factors in nugget detecting success or failure.
    A quick note to those who know nothing about these machines. These are metal detectors. There is no such thing as a "gold only" detector. These detectors will also find lead, copper, aluminum, and other metals. These units are best used to look for relatively larger pieces of gold at relatively shallow depths. Concentrations of gold dust are not detectable. Some of these units can hit gold that weighs as little as a grain (480 grains per ounce) or less but only at an inch or two. Only the larger nuggets can be found at depths exceeding a foot. Only world class nuggets weighing many ounces can be detected at over two feet. The vast majority of nuggets found are found at inches, not feet. About Long Range Locators (LRLs)
    WARNING ON COUNTERFEIT DETECTORS - The market for nugget detectors far outsells coin and relic detectors worldwide, with huge sales in third world countries. This has made many of the models below very popular with counterfeiters. Here are some Fisher and Minelab examples. If you shop these models there are two simple rules. First, you are safe if you stick with approved dealers. Second, if the price seems too good to be true, beware! All legitimate dealers have a limit on how low they can advertise, the Minimum Advertised Price (MAP). Review prices at the approved dealer list, and if you find the detector advertised as new at a significantly lower price by somebody not on the list, the odds are very high you are looking at a counterfeit detector. Legitimate dealers are prohibited from advertising at those kind of prices, and a price too good to be true is your number one warning you are about to be ripped off.
    The detectors are listed in order based on the lowest price normally advertised on the internet as of the date below.
    Steve's Guide to Gold Nugget Detectors - Updated January 2024
    Before I start, a quick note about recent events in the metal detector industry. A few years ago we lost a major manufacturer in the form of Tesoro. That lead to the Tesoro Lobo SuperTRAQ being dropped from this list. 2020 saw one of the true industry stalwarts fall by the wayside. White's Electronics was acquired by Garrett in October of that year. I am therefore dropping the White's nugget detectors from this list as no longer available new with warranty. For now, see my detailed reviews for information on White's models.
    Bounty Hunter Time Ranger Pro / Fisher F19 ($399, 19 kHz) - This detector is a later, more advanced version of the Fisher Gold Bug Pro (see below), with added features. There is an excellent threshold based all metal mode plus a dual tone discrimination mode. The F19 has both ground grab and manual ground balance, plus adjustable tone break, just like the Gold Bug Pro. Extra features are added to enhance the coin, relic, and jewelry capability, such as notch discrimination with adjustable notch width, volume control, separate ferrous tone volume, and a LCD meter backlight. These extra features may even find use while gold prospecting. The Fisher F19, and the Bounty Hunter Time Ranger Pro, can use any Gold Bug compatible coils plus those made for the Teknetics G2 series, providing for a huge number of possible accessory coils. This detector can be had with several stock coil options, including a 7" x 11" DD coil, or 5" x 10" DD coil. Weight including a single 9V battery is 2.6 lbs.
    Steve's Opinion - If you can afford it, look at other options below. If you want the lowest price detector worth even looking at for nugget detecting, you can look no farther than here at $399 (or less). First Texas, the manufacturer of Bounty Hunter, Fisher, and Teknetics metal detectors, sells quite a few identical or near identical metal detectors under different brand names and model names. Due to oddities in their marketing scheme, some more powerful models are often available at lower prices than other less capable models. Currently the 19 kHz Gold Bug name carries a premium price, while other identical or more capable models, sold under other names, can often be had for less money. That is currently the case with the 19 kHz Fisher F19 models, and the identical Bounty Hunter Time Ranger Pro model. The bottom line is this. If you can find a BHTRP/Fisher F19 with 5" x 10" elliptical coil for under $500 at a legitimate dealer (see counterfeit note above) it is easily my current recommendation for an extremely capable, entry level, VLF nugget detector with general purpose capabilities. I recommend this detector over the Fisher Gold Bug and Gold Bug Pro models below, not only because of the extra capability, but because it can be had stock with the 5" x 10" DD coil, the best general nugget hunting coil for the FT 19 kHz series. It can only be had as an accessory coil on the Gold Bug models, driving their out of pocket cost even higher.
     
    Nokta Gold Kruzer ($549, 61 kHz) - Nokta/Makro started shipping the new Gold Kruzer model in June 2018 and with a change in the company name is now simply the Nokta Gold Kruzer. The Gold Kruzer is a variant of the old Makro Gold Racer that has been boosted to 61 kHz from 56 kHz and put in a waterproof housing good to 5 meters (16.4 ft). The Gold Kruzer comes with a 10" x 5" concentric coil and a 4" x 7.5" DD coil. The weight including LiPo batteries is 3.0 lbs. There are four coils available for the Gold Kruzer.
    Steve's Opinion - The Makro Gold Racer was one of my favorite detectors because until recently there was nothing running in this frequency class that had full target id and other options normally seen only in coin detectors. The Gold Kruzer takes it all to the next step by being waterproof in excess of ten feet. There are no other detectors running at a frequency this high that are fully submersible with built in wireless capability and therefore this detector may find favor with freshwater jewelry hunters as well as prospectors. The Gold Kruzer is worth keeping an eye on, and is a better value than it appears at first glance due to the dual coil packaging. 2024 Note: The Gold Kruzer has been reduced in price from over $600 to only $549 which seriously upsets the cart. This is an incredible value for what you get and well worth consideration.

    Fisher Gold Bug Pro ($599, 19 kHz) - Essentially the same as the Gold Bug above with the addition of manual ground balance. The target ID makes the Gold Bug Pro good for more than just nugget hunting, and it will find favor with jewelry and relic hunters. The manual ground balance gives expert operators the control they desire to get the best depth possible. This unit normally comes with a 5" round DD coil to enhance the sensitivity to small gold but other standard coil packages are available. Weight including a single 9V battery is 2.5 lbs. Many accessory coils are available for the Gold Bug Pro. 
    Steve's Opinion - The Pro is the final version in this series which saw several early variations including the Gold Bug above. It is a excellent choice for prospecting, relic, or jewelry detecting and does fine as a coin detector also. However, you are now paying a premium for the Gold Bug name, and the more capable Fisher F19 at the top of this list can be had in a better configuration at a much lower price. The Nokta. Unless you just want the name, pass.
     
    XP ORX ($599, 14, 28, 56, 80 kHz) - The XP ORX emphasizes gold prospecting and coin detecting in the promotional material. The XP ORX appears to be a version of the "Africa only" Depar DPR 600 made for sales in Europe, the U.S., and elsewhere. The ORX has been refined from that early effort by the addition of the ability to use the new X35 coils.
    Steve's Opinion - The XP ORX went through some teething pains with coils before settling into its final role as XPs gold nugget detector. I think the ORX is a great little nugget hunter personally (I love the compact design), but it seems to be overlooked my most serious prospectors, and getting more attention as a low cost alternative to the XP Deus for coin and relic detecting. The new lower price makes the ORX a serious contender, a big step up in capability from the Fisher 19 kHz models above, and a little less money than the Garrett 24K below for a more full featured detector.
     
    Garrett AT Gold ($639, 18 kHz) - The AT Gold was a totally new concept in metal detecting from Garrett Electronics when it was introduced. This full featured detector has everything you would expect from a dry land detector - LCD display, full control set and functions, speaker, interchangeable coils, and lightweight. But it is submersible to 10 feet! Even the speaker is waterproof. Note that the unit itself may be submerged but if you want to put your head underwater you will need optional submersible headphones. Weight including a four AA batteries is 3 lbs. The stock coil is a 5" x 8" DD elliptical. Many accessory coils are available for the AT Gold.
    Steve's Opinion - The Garrett AT Gold was an innovative concept when it was introduced, and was the only waterproof nugget detector option at the time. The nugget hunting world has moved past the AT Gold now, and unless it comes down in price it's hard to recommend for somebody interested primarily in a nugget detecting VLF. Only for Garrett fans really, and even then more for the relic hunting crowd. For a much better option, see the Garrett Goldmaster 24K below or one of several less expensive models above, like the Nokta Gold Kruzer.
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    Garrett Goldmaster 24K ($679, 48 kHz) - The Garrett Goldmaster 24K is a reintroduced version of the White's Goldmaster 24K, the sole model that Garrett has continued to manufacture after purchasing White's. This is due to it being the latest in VLF nugget hunting technology, with a perfect balance of features for advanced nugget hunters, yet ease of use for beginners. All this in a well balanced, weatherproof package, with good accessory coil support. Better yet, Garrett went through the design from top to bottom, vetting the electronics, and in particular, upgrading the coils for better performance and reliability. The weight including 8 AA rechargeable batteries is 3.4 lbs. The 24K comes stock with a 6" x 10" elliptical coil with scuff cover included. An excellent 6” round concentric is available as an option.
    Steve's Opinion - White's Electronics went out of business in 2020, and was purchased by Garrett Metal Detectors. This makes Garrett now one of only two remaining U.S. metal detector manufacturers. I place them at first place in that role, due to the overall consistency of their existing product line, now augmented by the White's purchase. The White's line will be largely dropped as out of date for today's market. However, the last White's model produced, the Goldmaster 24K, is a superior product, and extremely competitive in its class. I personally had settled on it as my preference over other 30 kHz plus dedicated prospecting detectors, due to the overall physical design, tuning options, and affordable coil selection. The 24K is my personal VLF gold nugget hunter at this time but I have to admit that there are good reasons to consider the Nokta Gold Kruzer and XP ORX also due to recent price decreases from XP and Nokta.
     
    Fisher Gold Bug 2 ($799, 71 kHz) – The Gold Bug 2 is the highest frequency detector on the market, for extreme sensitivity to the smallest gold nuggets. In moderate to low mineral conditions, no detector will pick up a smaller nugget than the Gold Bug 2, especially if it is paired with its 6.5” accessory coil. The lightweight and tough hip mountable design is great for rough terrain. The Gold Bug 2 is a manual ground balance unit. Weight including two 9V batteries 2.9 lbs. The unit can be purchased stock with either the 10" elliptical coil or 6.5" elliptical coil, or both. Two accessory coils are available for the Gold Bug 2.
    Steve's Opinion - An excellent example of a niche machine that excels at one task. The Gold Bug 2 has extreme sensitivity to small gold combined with what I feel is one of the best physical designs of any nugget detector on the market. The Gold Bug 2 is lightweight, tough, and convertible from rod mount to chest or hip mount. Its main drawback is that it is harder for beginners to learn than newer units since it has no automatic ground tracking or ground "grab" options.. But if mastered and paired with the small 6" coil the Gold Bug 2 is a superb small gold machine. The Gold Bug 2 has a particularly effective "Iron ID" mode that not only rejects iron targets but many iron hot rocks. I consider my Gold Bug 2 my "go to" detector if I simply want to find some gold. I can hit tiny pieces weighing less than 1/10th grain with the 6" coil. 8/2021 Note: The Gold Bug 2 has just been reintroduced with a LCD screen displaying the ground balance setting, but is still the same detector, just with a control update. Still a great old machine, a classic really, and holds it's own with the best made today. 

    Minelab Gold Monster 1000 ($999, 45 kHz) – The Minelab Gold Monster 1000 came out in 2017. The model is replaces the Minelab Eureka Gold as a much lighter and less expensive detector. Main features are a hot 45 kHz frequency combined with automatic ground tracking and even an automatic sensitivity option. The Minelab Gold Monster comes with a 5" round DD coil plus rechargeable and standard AA battery packs (AA batteries not included).
    Steve's Opinion - I have been a little surprised how I took to the Gold Monster 1000. This has been based more on its grab and go simplicity than anything else. It has excellent sensitivity to small gold and and dual coil package for a good price. The main issue for beginners is to resist over-driving the sensitivity which can lead to false signals. The big selling point for the Gold Monster is the minimum control set and almost totally automatic operation. Some professionals however may chafe at the lack of audio threshold and the very same limited amount of control that appeal to others. I’m personally do not like the screw together rod at all, a stand out flaw for an otherwise excellent detector. Still, the ease of operation is a huge plus for beginners, and this has made the Monster a very popular option.
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    Minelab Equinox 800 ($999, 5, 10, 15, 20, 40 kHz plus Multifrequency) – The Minelab Equinox 800 has just been released and is only now becoming available in quantity. It includes a dedicated Gold Mode with up to 40 kHz operation and offers the first true multifrequency nugget detecting capability.
    Steve's Opinion - The Minelab Equinox 800 has excellent sensitivity to gold nuggets in mineralized ground. I have been very impressed with what I have been able to make the Equinox do as a gold prospecting detector. The stock 11" coil is less than ideal for nugget detecting, being knock sensitive under some conditions, but the new optional 6" x 10" coil is proving to be very stable, and has great sensitivity to very small gold. I am not recommending all prospectors run out and get an Equinox per se. It is primarily a general purpose detector, and its settings and operation will be foreign to many experienced nugget hunters. However, if you want a very capable general purpose detector, that is also quite capable at finding gold nuggets, the Minelab Equinox is a proven choice. In the right hands, a case can be made for it being a superior nugget detecting option, despite the caveats I've mentioned. Equinox nugget detecting tips.

    A note on Pulse Induction (PI) detectors. Pulse induction detectors are a more powerful option for prospectors compared to the models above. Their main advantage is the ability to handle highly mineralized ground and hot rocks more effectively than the induction balance detectors listed above. Unfortunately PI detectors have rudimentary discrimination compared to VLF units. It is best to view PI units as all-metal, dig-it-all detectors. They do have some limited discrimination capability, but it is not why you get a PI unit. Depth in extreme mineralized ground and an ability to ignore difficult hot rocks are the selling points. In addition, some PI units have poor sensitivity to small gold compared to VLF units, and so someone with less expensive VLF unit can run circles around someone with a PI unit at low mineral locations. I tend to consider PI units as elephant hunting guns, best used when larger nuggets are known to be lurking in an area. New PI detectors like the SDC 2300 are challenging my perception in that regard however. Some areas demand PI detectors regardless of gold size due to extreme mineralization and/or hot rocks. My basic recommendation for most people is use a VLF when you can, and use a PI when you have to. You first clue to when this will be is when you can't get your VLF to work properly due to ground and hot rock conditions. In much of the US a good VLF is perfectly suitable and often a better choice than a PI. However the western US and most of Australia have places where a PI is an absolute necessity.

    Garrett ATX ($2120, Pulse) - This model takes the AT series to a new level with pulse induction. It features an extremely compact military grade housing submersible to 10 feet. Even the built-in speaker is waterproof. Note that the unit itself may be submerged but if you want to put your head underwater you will need optional submersible headphones. The ATX features a unique collapsible/folding design for stowing and backpacking. It is powered by eight AA batteries. The ATX comes with a newly designed 10" x 12" DD coil and weighs 6.9 lbs. Four accessory coils are available.
    Steve's Opinion - The ATX is a very versatile detector, and fully capable of almost any task a person wants to use it for. The ATX is a superior beach detector, and the least expensive pulse induction nugget detectors currently available. It is sensitive to gold nuggets weighing as little as 0.1 gram and yet has very respectable depth on larger gold nuggets. I think the ATX has a performance edge over the TDI SL but at twice the price and twice the weight it has not set the prospecting world on fire. The main problem is the heavy waterproof housing driving the price up so high, that in Australia the ATX does not compare favorably to the much more popular Minelab models. In the U.S. it has settled into being most used for beach and relic detecting. At this point unless having a waterproof detector is critical, or you are on a very tight budget, spending the extra money to get the Garrett Axiom below is a far better option.
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    Minelab SDC 2300 ($3599, Pulse) - This model is unique as Minelabs first waterproof pulse induction metal detector. A key feature is that the detector is physically packaged in the proven F3 Compact military housing that is waterproof to ten feet and folds down into an incredibly compact package only 15.7" long and weighing 5.7 pounds including four C cell batteries.
    Steve's Opinion - I have used the Minelab SDC 2300 and I must say I was impressed. The waterproof compact design is perfect for hardcore backpack style prospecting. The main thing however is that the SDC 2300 comes as close to VLF type performance on small gold as you can get while being almost impervious to the ground mineralization, and hot rock issues, that plague said VLF detectors. In fact, the SDC 2300 will find gold nuggets smaller than most good VLF detectors can detect in mineralized ground. The SDC 2300 is also one of the simplest detectors to use and master on the market. The main caveat is that the detector is optimized for small gold with the hardwired coil, and so other ground balancing PI detectors are a better option for large nuggets at depth. It is also nearly twice the price of the Garrett ATX above, and so you are paying quite a premium for a little better performance on small gold. Still, the SDC 2300 is almost impossible to beat for the price, if the goal is just to go find some gold, any gold at all. If the budget allows, however, at this point I would pass, and go to the new Garrett Axiom below, which offers a much more sensible design, with many more coil options, and better capability for larger gold at depth.

    Garrett Axiom ($3995, Pulse) - A new pulse induction gold nugget detector, just announced for 2022, available by the end of the year. The Garrett Axion is the first pulse induction nugget detector to truly reflect 21st design options and capabilities. The Axiom is a sleek, modern design, perfectly balanced at only 4.2 lbs with the 11" x 7" mono coil. The detector is fully weatherproof, with waterproof coils. The Garrett Axiom is available in a couple package options, but the most popular will include the 11" mono coil, 13" DD coil, and Garrett Z-Lynk high speed wireless headphones. The Axiom has a perfect balance of controls, giving experts more options than more simplistic designs, while still focusing on only the controls really needed, to keep things easy for beginners.
    Steve's Opinion - Well, I have to admit I'm biased on this one. I lobbied Garrett every way possible for almost a decade, to make a detector like the Garrett Axiom. So it is literally a dream come true for me, a powerful pulse induction detector in a really great, ergonomic package, and at a price that won't break the bank, but honestly still more expensive than I was hoping for. I have used the Axiom already enough to know that it is very competitive although it is not that it is the most powerful option available. For that I refer you to the Minelab GPZ 7000 below. The Axiom goes head to head with the GPX 6000 and basically offers 90% of the performance of that machine for two thirds the price.

    Minelab GPX 5000 ($3999, Pulse) - This Pulse Induction (PI) unit essentially ignores ground mineralization and most hot rocks. The GPX 5000 is designed specifically for nugget detecting and so it has many adjustments for mineralized ground not available on other PI detectors. The GPX 5000 is the culmination of over 10 years of innovation in pulse induction technology. The GPX weighs 5.3 lbs. not including the harness mounted battery, which weighs another 1.7 lbs. The detector comes with both an 11" round mono coil and 11" round DD coil. Over 100 accessory coils are available for the GPX 5000 (Minelab, Coiltek, Nugget Finder)! And more coils are being released every year.
    Steve's Opinion - The Minelab GPX 5000 can at this point be considered the reliable, well proven option, for just about any pulse induction task a person wants to consider. It has found a wide audience not just with nugget hunters, but with beach and relic hunters. This is in large part due to the incredible coil selection. For general nugget hunting however, the GPX 5000 faces new competition in the form of the Garrett Axiom above, for almost the same price. The Axiom is a better package from a physical perspective and more capable than the GPX 5000 on bread and butter small gold nuggets. However for 1/2 ounce and larger nuggets the GPX 5000 still has the edge due to it's superior large coil selection. personally I lean Axiom for the ergonomics but a case can be made for either machine depending on the user.

    Minelab GPX 6000 ($6499, Pulse) - The Minelab GPX 6000 is a new pulse induction model that is just now getting into end user hands. The GPX 6000 is exceptionally light and well balanced compared to previous Minelab models, and promises to set new standards for ease of operation. The GPX 6000 weighs 4.6 lbs. and has three coils available at launch, an 11" round mono, 14" round DD, and 17" elliptical mono. The detector has built in Bluetooth wireless headphone capability and quick release Li-Ion batteries.
    Steve's Opinion - Minelab beat Garrett to the punch in making a very ergonomic metal detector for the 21st century. The GPX 6000 is an excellent choice for gold prospectors, with out of box sensitivity on smaller gold that exceeds the Minelab GPZ 7000. Sadly, what should have been rave reviews by users, has been muted by persistent issues regarding bad coils and hardware based electrical interference. I admit I feel like I have a little egg on my face, as I raved about the GPX 6000 a lot when it came out since mine had none of the problems that far too many people have been experiencing. Regardless of that, I still think when it is running like it should, the GPX 6000 is a superb detector. The closest competitor is the Garrett Axiom for $2500 less. I do think the GPX 6000 retains a small performance edge over the Axiom but whether it is worth the 50% higher price will depend on the user. The more you use a nugget detector, the less the price difference matters.

    Minelab GPZ 7000 ($8999, ZVT) - The new Zero Voltage Transmission technology from Minelab takes gold prospecting to the next level. The new platform represents a break from the past SD/GP/GPX series in more ways than one, with a new weatherproof housing design based on the Minelab CTX 3030. The GPZ 7000 weighs 7.32 lbs. and comes with a waterproof 14" x 13" coil. There is one official accessory coil available at this time, plus one officially sanctioned aftermarket coil, but more are coming as I type. Brave souls can check out numerous hacked Russian coil options.
    Steve's Opinion - It's pretty simple. If you want the most powerful metal detector made for finding gold nuggets, get a Minelab GPZ 7000. The GPX 6000, Garrett Axiom, and even SDC 2300 can beat it out of box on the tiniest gold nuggets. But the 7000 will hit stuff plenty small, and more importantly, deliver the goods on the bread and butter gold that matter most to genuine prospectors who want to put weight in their pocket. The difference in small gold capability can be made up with options aftermarket coils, meeting or exceeding what the other models mentioned can do. Yes, it is heavy, and it is expensive, but most really serious gold prospectors are using the GPZ 7000 for a reason - when it comes to sheer performance, it's the best machine for the job.
     
    A Steve's Opinion summary - So maybe all the above is still too much information, too many choices. And you want to ask "what would you do Steve?" Well, I'm not trying to speak for anyone but myself, but here is my current thought on the situation. If you want a really great VLF nugget detector in 2024 at a great price the Nokta Gold Kruzer and XP ORX are standout values at under $600. Both are excellent VLF nugget machines and both can be used for more than just nugget detecting. The Gold Kruzer coming with two coils and being fully waterproof would be my choice.
    As far as PI goes for me it's either GPX 6000, or Garrett Axiom. If money is no object and you only ever intend to use the machine for nugget detecting, then the 6000 wins the day. For me I do more than just nugget hunt so I find the Axiom to be a better general purpose PI for my uses, even though I am giving up a small edge on small gold nuggets. If sheer power is all it's about, weight, price, nothing else matters, just performance, I still think a person has to go GPZ 7000. Yeah, for specific situations other machines might be better. Heck, a Gold Bug 2 might be better in the right spot! But overall, if I had to pay my bills with gold found, I'd be using a GPZ 7000.
     
    If I can offer one final word of advice, it would be to pay particular attention to what experienced nugget hunters are using in any particular region. Do not assume you are going to outsmart them, and find some model they have not already tried, and set aside, as less than optimum. Serious prospectors in any particular location will end up focusing on certain units that do the job. In areas of extreme mineralization this is usually a PI detector. In areas with less mineralization and lots of ferrous trash VLF units often are preferred. If you can discover what models the locals prefer, it will give you a head start in knowing what to use yourself. Above all, whatever detector you finally choose, dedicate yourself to mastering it. It takes at least 100 hours of detecting to become proficient with a detector model. Any less, and you are still practicing. Knowing your detector well is more important than what particular model of nugget detector you own.
    So there you are. Hopefully this helps some people out. I can be found daily on the Detector Prospector Forums and would be pleased to answer any questions you have on metal detecting and prospecting. Also check out Steve's Guide to Metal Detecting for Gold Nuggets.
    Sincerely,
    ~ Steve Herschbach
    Steve's Mining Journal
    Copyright © 2002 - 2024 Herschbach Enterprises - Please do not reuse or repost without my express permission.
     
  • Steve Herschbach
    Well, here I am, another year older, and 48 years of metal detecting and gold prospecting under my belt! 2020 has been an odd year for many reasons, the main being the pandemic that has wrecked havoc on life around the planet. The resulting shutdowns and social distancing requirements made this a challenging year for everyone, whether they caught the virus or not.
    Once I saw where things were headed, I decided to gracefully accept that 2020 would be a good year to just kick back and relax. I did get in some metal detecting during the year, but it has been more about trying out some new detectors than making actual finds. I had a good time and learned a few things, but this was the first year in a long time that I had no specific "adventure" planned for the year. If you look back over my journal, you will see I have done well over the years at making some sort of special prospecting or metal detecting trip each year. This year however it was short day trips, or at most a few overnight outings. Travel did not seem like a good idea this year, especially anything involving airplanes.

    Some gold found by Steve while metal detecting in 2020
    I made finds for the year; gold nuggets, coins, and jewelry. There was no one find however that stands out at all in my mind, more a reflection of how spoiled I am than anything else. In some ways it was a very nice year for me, just taking it easy and having fun. However, I would like to ramp it up for 2021, and I will make the effort in the coming year to try new places and locations more than I did in 2020, which was mostly revisiting old haunts. Happy New Year!
    ~ Steve Herschbach
    Copyright © 2020 Herschbach Enterprises
    Go To Prior Story     Journal Index Page
     
  • Steve Herschbach
    This page has links to a collection of online "books" about prospecting and metal detecting subjects of interest. Most of these were actual printed books or brochures that are now available as html or pdf documents. In the case of pdf documents especially you can download and save these creating your own library of essential information. Many of these are out of print and hard to find so we are very lucky they are being scanned and made available on the internet. Be sure to also visit Steve's Guides - articles about basic metal detecting and gold prospecting subjects collected from forum posts on this website over the years.
    Metal Detecting
    How Metal Detectors Work by Mark Rowan & William Lahr - Originally published by White's Electronics as a booklet P/N 621-0395. Basic technical information on how induction balance and pulse induction metal detectors work. Metal Detector Basics and Theory by Bruce Candy - Bruce is a co-founder of Minelab and the man behind their most advanced designs. This information delves into much greater detail than the above link and has many more illustrations and diagrams. Metal Detecting Terminology - Metal detecting terminology and definitions, with an emphasis on Minelab technology wording and descriptions. The Sport of Coin Hunting by Charles Garrett. The basics of finding coins with metal detectors. The author designed and built his own metal detectors, and Garrett Electronics was established in 1964 to manufacture and market his inventions. How To Search Sand & Surf by Charles Garrett. Treasure recovery at the beach including coins and jewelry. Introduction to European Metal Detecting by Charles Garrett. Metal detecting for coins and relics in Europe. The author designed and built his own metal detectors, and Garrett Electronics was established in 1964 to manufacture and market his inventions. Gold Prospecting with a VLF Metal Detector by Dave Johnson. Dave is the Chief Designer for First Texas Products and has been involved in designing most of the VLF gold prospecting detectors sold over the last 30 years. This is an excellent primer on using VLF detectors to prospect for gold. Coil Size vs Detection Depth by Carl Moreland, on this website forum. A chart with notes from PI guru Eric Foster illustrates the relationship between coil size and depth on PI detectors. The History of Metal Detectors, with Emphasis on Gold Prospecting from First Texas (Bounty Hunter, Fisher, Teknetics) by Dave Johnson. A talk given to the El Paso Chapter of the GPAA February 12, 2008. Metal Detecting Technologies for Gold Prospecting from First Texas (Bounty Hunter, Fisher, Teknetics) by Dave Johnson. A short essay of key technologies for gold nugget detecting. Understanding the PI Metal Detector by Reg Sniff. An excellent, understandable primer on pulse induction metal detectors. Metal Detector Information - Get lots of great answers to basic detecting questions along with info and field reviews of Tesoro detectors. Common Questions About Metal Detecting from White's Electronics. Fisher Intelligence 5th Edition by Thomas Dankowski. Thought provoking articles on aspects of metal detecting not often talked about. Advanced Nugget Hunting with the Fisher Gold Bug Metal Detector by Pieter Heydelaar and David Johnson. This out-of-print book is a good basic text on nugget detecting. Although it uses the original Fisher Gold Bug as an example the information applies to most nugget detectors. Part 2 by David Johnson is an excellent primer on hot rocks. The Painful Truth by Thomas Dankowski - There is more good stuff left to be found but hidden from current technology - read why. A follow up to Dankowskis classic Beneath The Mask article. Head-To-Head Comparison Testing by Thomas Dankowski. It is not as easy as it looks! Why people get different results testing metal detectors, and how to do it properly. Halo Effect & Related Ground Oddities - from Fisher by Dave Johnson. An explanation of factors that can possibly enhance detector depth - myth or reality? White’s MXT Engineering Guide - by Dave Johnson. An inside look at the metal detector design process, with details about the White’s MXT and GMT models. An Engineers Guide to the Spectrum XLT - by Mark Rowan. The details behind the design of the innovative White’s SignaGraph display, first used in the Spectrum XLT detector. Steve's Guides - Articles about basic metal detecting and gold prospecting subjects. Metal Detector User Guides & Catalogs - User guides, catalogs and brochures from various manufacturers. ads by Amazon...
    Prospecting
    Determining Where To Prospect For Nuggets 2017 Detector Prospector Forum article by Steve Herschbach How To Find Gold Metal Detecting & Panning by Charles Garrett. The basics of gold panning and metal detecting for gold nuggets. The author designed and built his own metal detectors, and Garrett Electronics was established in 1964 to manufacture and market his inventions. Handbook of Geophysical Prospecting Methods for the Alaskan Prospector A dated but still realistic summary of electronic deices used in the prospecting industry, aimed at the individual prospector. Geophysics For Mineral Exploration - A Manual For Prospectors A more recent publication that updates the one above, read both. Principal Gold Producing Districts of the United States 1968 USGS Professional Paper 610 by A. H. Koschmann and M. H. Bergendahl - A description of the geology, mining history, and production of the major gold-mining districts in 21 states. Placer Deposits of Alaska 1973 USGS Bulletin 1374 by Edward H. Cobb - An inventory of the placer mines and prospects of Alaska, their history and geologic setting. Metalliferous Lode Deposits of Alaska 1967 USGS Bulletin 1246 by Henry C. Berg and Edward H. Cobb - An inventory of the mines and prospects of Alaska and their geologic settings. Gold Prospecting Research Material for Alaska - Detailed prospecting resources for Alaska. Placer Gold Deposits of Arizona 1972 USGS Bulletin 1355 by Maureen G. Johnson - A catalog of location, geology, and production with lists of annotated references pertaining to the placer districts. Gold Placers and Placering in Arizona 1961 Arizona Bureau of Geology and Mineral Technology Bulletin 168 by Eldred D. Wilson Gold Districts of California 1970 California Division of Mines and Geology Bulletin 193 by William B. Clark. A relatively up-to-date and comprehensive guide to the gold deposits of California. The Tertiary Gravels of the Sierra Nevada of California 1911 USGS Professional Paper 73 by Waldemar Lindgren. A California geology classic. An account of the Tertiary formations of the Sierra Nevada Mountains and the origin and distribution of the gold-bearing (auriferous) gravels. Placer Gold in Southwestern Colorado 1960 by Ben H. Parker, Jr. - Excerpted from The Geology of the Gold Placers of Colorado, an unpublished doctoral dissertation of the Colorado School of Mines. Placer Gold Deposits of Nevada 1973 USGS Bulletin 1356 by Maureen G. Johnson - A catalog of location, geology, and production with lists of annotated references pertaining to the placer districts. Placer Gold Deposits of New Mexico 1972 USGS Bulletin 1348 by Maureen G. Johnson - A catalog of location, geology, and production with lists of annotated references pertaining to the placer districts. Placer Gold Deposits of Utah 1973 USGS Bulletin 1357 by Maureen G. Johnson - A catalog of location, geology, and production with lists of annotated references pertaining to the placer districts. Placer Examination Principles And Practice - 1969 BLM Technical Bulletin 4 by John H. Wells - The classic work on evaluating precious metal placer deposits. ads by Amazon...
  • Steve Herschbach
    I have added two new sections to the website that cross link to each other. The first is a Metal Detector Database with User Reviews. Most current name brand metal detectors are listed with basic specs like price, weight, water resistance, etc. You can sort the listing by these basic specifications and you can leave your own review of each detector. Discontinued models are now being added. The new area is accessed in the menu under "Reviews"
    The second area is a revamped Downloads Area. Various manufacturer catalogs are collected there for historical reference to models, specifications and prices. More importantly, each detector in the Reviews database has it's user guide listed for download plus any other pertinent documents like sales flyers.
    Basically the Reviews area links to the Downloads area and vice versa. This is all under construction still and will be for some time as regards discontinued models. I am adding cross links and new listings almost daily. Hopefully this will allow people easier access to information and manuals now scattered across the internet. Please do your part by leaving reviews of any metal detectors you have used. Thanks!

  • Steve Herschbach
    I recently treated myself to a metal detecting holiday to the area around Colchester, England. This was a reprise to a trip I made to the UK in 2010 in search of Celtic gold. Gold was not in the equation for that trip, but I did find the oldest coins and artifacts I have ever found.... as in 2000 years older than anything I have found before!
    Colchester has history reaching back into prehistoric times, and is generally acknowledged as the location of Britain's first city. Celtic tribes were active in the area, leaving behind many Celtic gold coins to be found by modern day detectorists. The Romans were also very active in the area, as were other invaders, leading to finds from many cultures across the centuries.
    I made a return visit to Colchester in 2018, this time relying heavily on the new Minelab Equinox metal detector as my detector of choice. I also had the opportunity to use the new Minelab Equinox 15" x 12" DD coil while on this trip. Not only did I have a very successful trip, but I got to observe other great finds made by the other detectorists in the group. All in all this was a very exciting metal detecting experience that I enjoyed thoroughly. The links below outline both my own experiences and the same trip told from the perspective of another person on the same adventure.
    Steve's 2018 UK Adventure by Steve Herschbach
    My UK Trip .... Double Ancient Gold! by Ill Digger

    Steve Herschbach finds ancient UK gold!
     
  • Steve Herschbach

    XP Orx

    By Steve Herschbach, in Steve's Reviews,

    The XP metal detector company has announced a new model for late 2018 called the XP ORX. This new model appears to be a refined version of the XP manufactured Depar DPR 600. The DPR 600 was made to take advantage of the African gold rush by offering a model designed primarily as a gold prospecting detector with other uses taking a back seat. I personally think the Depar DPR 600 was used as a proving ground for the new high frequency (HF) coils while also offering an opportunity to fine tune the Gold Field program. My expectation all along is that XP would eventually release a similar model for sale outside of Africa. It looks like after almost two years that new refined version of the DPR 600 is available for purchase as the XP ORX.
    This introduction is so new that information at this time is limited - everything here is subject to change as new details emerge. For now what we know for sure is that the XP Orx will be available in two configurations. The versions are basically the same, with a wired headphone version for 700 Euro, and a wireless headphone version for 800 Euro. U.S. pricing is unknown at this time but $799 and $899 is probably in the ballpark. You can choose either the 9" round HF coil or 5" x 9.5" elliptical HF coil. There is no exact word on availability yet, but presumably we will be seeing this model available for purchase in early 2019.

    XP ORX gold prospecting metal detector
    It is possible hints about the new XP Orx can be gleaned by reading the DPR 600 User Manual. One main difference is in the User Modes. The DPR 600 and XP Orx both have four preset programs plus two user custom program slots for saved programs. The programs on the DPR 600 are designated as 1. General 2. Large Gold 3. Fine Gold 4. Iron Discriminate. The XP Orx is designed for a bit wider appeal, and so it looks like the General and Iron Disc modes have been recast as coin hunting modes. The modes on the XP Orx are 1. Gold 2. Fine Gold 3. Coin Fast 4. Coin Deep
    ORX Key features:
    HF coil technology (21 Frequencies ranging from 13 to 81kHz). Extreme sensitivity to small targets with high frequency 50kHz and 81 kHz. 4 factory programs: Gold Prospecting (x2) – Coins and Relic (x2), + 2 user. Trusted XP fast wireless technology: Coil – Remote – Headphones – MI-6. The all new “WS Audio®” compact wireless headphone receiver. Re designed ultra-light Telescopic “S” stem. The lightest machine on the market at only 770grs (remote hip mounted). Easy to operate with a user-friendly interface. Wireless connectivity to the MI-6 pinpointer + advanced remote settings. Lithium batteries, giving up to around 20 hours of detecting. Easy to charge with any certified USB charger or via computer (XP USB charger optional only) Available with a choice of HF coils – 22cm (9") Round or 24/13cm (9.5"x5") Elliptical. Compatible with the X35 coil range (22, 28, 34/28cm). Software Update (remote control via USB cable). Go terrain mobile app compatible (coming 2019). 5-year warranty – Made in France. Affordable price – Suggested maximum retail price: 699€ including taxes – 799€ including taxes with wireless headphone (WSA). Note that the upper armrest area of the rod has been redesigned and is different than the existing Deus rod assembly.

    XP ORX Controls & Settings
    ORX settings:
    99 levels of sensitivity 21 frequencies (13 kHz to 81 kHz). 99 levels of discrimination + 5 levels of IAR Discrimination in Gold programs. 20 levels of Threshold. 4 levels of Reactivity. Iron Tone with Pitch audio (ON/OFF) Ground balance: manual adjustment from 60 to 90 or automatic (fast grab). Salt mode ground rejection: 00-25 4 factory + 2 user programs. Target ID/ Iron probability. Pinpoint function with target zoom. Go-Terrain compatible (smartphone app coming soon). ads by Google...


    XP ORX MI-6 Compatibility
    Advanced remote settings when the ORX is paired with the MI-6 pinpointer:
    50 levels of sensitivity Audio tone from 120 Hz to 1582 Hz 2 audio modes: PITCH or PULSE 3 factory + 1 user program Recover a lost MI-6 (even when switched off) Target zoom screen Battery life indicator I don't think there is much mystery here except for how many people will opt for this new model versus the new X35 coil based Deus models. In my opinion by extending the top end frequency of the new X35 coils to 28 khz has inadvertently removed some of the demand for this higher frequency version. Small gold sensitivity gains over 30 khz are quite minimal and with the extra features the Deus offers many people may continue to prefer it as their detecting solution. A lot may boil down to the price difference between a 9" round X35 Deus package and the 9" round HF Orx package.
    No matter what I am very confident this new high frequency XP model will do very well for gold prospecting. I do not expect performance to be any different than that I observed while testing the XP Deus with elliptical HF coil on small gold.
    XP Orx Data & Reviews
    XP Orx Owner's Manual
    Forum Threads Tagged "xp orx"
    XP Metal Detector Forum
    XP ORX Technical Specifications* Internet Price estimate $649 wired headphones or $795 wireless headphones Technology Induction Balance (IB) Frequency 14, 28, 56 kHz (round 9") or 14, 28, 70 kHz (elliptical) Autotune Mode(s) Multiple "Reactivity" Settings Ground Rejection Grab, Manual, Tracking Soil Adjust No Discrimination Variable, Visual ID, Tone ID, Notch Volume Control Yes Threshold Control Yes Tone Adjust Yes Audio Boost Yes Frequency Offset Yes Pinpoint Mode Yes Audio Output 1/8" headphone socket & speaker, wireless headphones Hip Mount Yes Standard Coil(s) 9" round DD or 9.5" elliptical DD Optional Search Coils new X35 coil series Battery Built In Rechargeable Operating Time 20 hours Weight 2.0 lbs Additional Technology Wireless coils, control box, headphones; firmware updates via internet Notes Probably based on "Africa Only" Depar DPR 600 *Notes on Technical Specifications - Detailed notes about the specifications listed in this chart.
     
  • Steve Herschbach
    White's MXT Engineering Guide
    David E. Johnson, engineering consultant
    This Engineering Guide is written to provide dealers and customers greater insight into what kind of product the MXT is, from an engineering perspective. It does not attempt to provide complete information on the features and use of the MXT: for that, please consult the MXT user's manual.
    A BIT OF HISTORY
    In January 1998, White's decided to develop a true multipurpose metal detector, with the kind of sensitivity it takes to be a real gold prospecting machine, and with computerized ground tracking for ease of use. White's in-house engineering staff was tied up on the project which eventually became the DFX. Therefore, in February White's asked me if I might be interested in taking on a new protect. I had a good track record on gold machines so it seemed like a good fit. I agreed.
    A month later at a dealer seminar in Sacramento, California, Jimmy Sierra announced the project, and said if the engineer didn't deliver, the engineer would have to go into hiding in Mexico. I was sitting in the back.
    We ran into one problem after another along the way. Jimmy, good chap that he is, didn't sic the thugs on me, though there were periods he was frustrated enough that the thought must have run through his mind. Although the project took longer than we expected we got two products out of it - the GMT and the MXT.
    The first major hurdle was to get the basic circuit and software system running, with a first class ground tracking system. The system architecture was totally new, not a revision of the existing Goldmasters. In early spring of 1999 an ugly prototype was up and swinging, and Larry Sallee became involved in field-testing. By April the ground tracking system was working so well that since that time very few changes have been needed. At that point we knew we had a solid foundation, so work began on the display, discrimination and target ID features.

    During the fall of 1999, we decided to tackle the problem of desert heat head-on. A lot of gold prospecting is done in desert heat in full sun. I set up a crude but effective, thermal engineering laboratory, measuring the temperatures reached inside housings of various configurations and colors in full sun. Then began the task of finding an LCD, which would handle the heat. Because the LCD display is an important feature of the MXT, we revisited the whole issue of display. The manufacturers of LCD display had expanded their product offerings. We found a larger one, and changed the mechanical design of the MXT to accommodate it. A FSTN 0160 F was selected, (there are more to choose from nowadays, so we used a bigger one than the GMT in the MXT.)
    In early 2000, White's decided to bring out a new Goldmaster based on the work that had already been done, while development of the multipurpose unit continued. So we modified a prototype to work with the Goldmaster search coil at about 50 kHz, and you know the rest of that story - the GMT "tracking Goldmaster" was introduced in early spring of 2001.

    As work continued on what eventually came to be called the "MXT", we spent a lot of time on the discrimination and target ID system. There are many different ways to do discrimination and ID, each with its own advantages and disadvantages, which aren't always known until you've had the thing in the field being tested for a while. A lot of work got thrown out as we found deficiencies in what had already been done, and discovered ways to improve things. As the project got closer to production, more people became involved with it, and offered their own ideas to improve it. The reason the MXT is as good as it is, is because of that long process of field-testing and revisions.
    While the MXT was still under development, the DFX was introduced. The MXT design was then revised to run at about 14 kHz in order to take advantage of the DFX loops.
    When it was finally time to call it "good" in June 2002, the MXT went into production quickly and smoothly.
    CIRCUIT DESIGN
    The circuitry of the MXT is almost identical to the GMT, which has already been on the market for a year and a half and has proven to be rock-solid.
    The GMT's circuitry broke a lot of new ground. It uses a reactive impedance transformation network to boost transmitter voltage for higher sensitivity. It uses an active transmitter regulator to keep transmitter voltage constant even when the search coil is moved over black sand that would blow an unregulated machine off the air. The differentiator-filter circuits usually found in metal detectors are eliminated. Those functions are now done in software, which is made possible by the use of a high-precision 16-bit A/D converter used in a way that makes it equivalent to 17 1/2 bits. All the controls are digitized, their function actually performed via software rather than in circuitry. The audio system is temperature compensated in software to eliminate threshold drift.
    For the MXT, we chose an operating frequency of 13.889 kHz. This is high enough to give good sensitivity to gold, low enough to give good target ID on typical coin, trash, and relic targets, electrically compatible with search coils derived from the DFX and halfway in between power line harmonics to minimize electrical interference.
    SOFTWARE
    The MXT uses a Microchip PIC 16C76 micro controller, chosen for its low power consumption and its set of features, which was a good match for this application. The software that runs in this chip is based on that in the GMT, but almost all of it is new or has major revisions, except the device drivers and the ground tracking system. Much of the new software is for target ID and discrimination, features that were not present in the GMT. Even the iron probability and VSAT systems in the MXT are new, despite their apparent similarity to the GMT.
    The MXT/GMT does as much of the signal processing as possible in software rather than in circuitry, using what we call "low-speed DSP architecture". The demodulated signals are digitized, and processed and analyzed in software. Control positions are also digitized and made part of the data in software. The desired audio signal is computed, and then converted back to voltage using a 12-bit D/A converter. The circuit board communicates with the LCD and trigger switch in the "pod" via a custom-designed serial link.
    In the MXT the filters, differentiators, and sample-and-hold functions are performed in software, not in circuitry. This eliminates the problems of channel mismatch and drift, which are often encountered in such circuits.
    The discrimination system is a second derivative ("two-filter'') design for quick response over a broad range of sweep speeds. The analysis system for determining what kind of target is present has special features which reduce interference from ground minerals, and which automatically scale target ID confidence according to the mineralization level.
    GROUND TRACKING SYSTEM
    The ground tracking system comprises two subsystems: a ground analysis engine, and a ground balancing system. The ground analysis engine continuously monitors incoming signals to determine whether the signals probably represent ground, or may be something else such as metal targets or electrical interference.

    Signals, which seem to be ground only, are put into a data analysis subsystem, which analyzes the data for a number of variables. Then it can be determined what the balance point of the ground matrix is and how fast that balance point is changing. It'd be nice to describe all this in detail but we'd rather not teach our competitors how to do it.
    The ground balance system does the actual balancing of the signals, doing in software somewhat the same job as a ground balance knob does on a manually balanced machine. When the TRAC toggle is in the "ground" or "salt" positions, the ground balancing system follows the output of the ground analysis engine. When the toggle is in the center "lock" position, the ground balance subsystem stops following the output of the ground analysis engine, which is still chugging away in the background continuing to gather ground data.
    The ground analysis engine can do a good job of telling the difference between ground matrix and anomalies such as hot rocks and metal targets. In order to tell the difference, it has to see matrix by itself during at least part of the sweep. When you're not in "lock", keep your sweeps broad, and don't loiter over the top of a target when checking it out. Otherwise the analysis engine may lose the ground matrix and start tracking into the target. However, if the target is strong enough to register on the VDI readout, the target ID system will tell the analysis engine to halt, allowing you to check the target without tracking into it. In all three programs, pulling the trigger to pinpoint a target also tells the ground analysis engine to halt. Some users will hunt with the tracking toggle in "lock", occasionally updating the ground balance by flipping into "ground" or "salt" momentarily when they start hearing too much ground noise.
    The resolution of the ground balancing system is 1 part in 4,000, and most of that resolution is concentrated in the range where high mineralization occurs. Therefore, the individual resolution steps are below audibility under all conditions.
    THE VSAT SYSTEM
    The VSAT system on the MXT is similar in a general way to the one on the GMT. The VSAT function is done entirely in software. Up to about 2/3 rotation, the SAT is of the conventional (first derivative or auto tune) kind, giving a "zip" sound on a nugget and a "boing" sound on a negative hot rock (cold rock).

    As you approach maximum rotation, the MXT goes into "HyperSAT". HyperSAT is a completely different type of SAT system with different sounds and target responses. The background threshold sound is a little rattier, but nuggets are crisper, the ground is quieter, and negative hot rocks vanish when you slow down your sweep. For all but the most experienced users whose ears are calibrated to hear every little nuance of a regular SAT signal, HyperSAT gives more effective depth in bad ground than normal SAT.
    THE DISCRIMINATION CONTROL
    The discrimination control does pretty much what you'd expect. Unlike some discriminators, when the control is at zero, there is no discrimination at all - i.e., "true zero discrimination" - and all targets will be detected. Below about 2, the discrimination is based on a combination of both signal phase, and signal strength relative to the strength of ground mineralization. This feature allows the user to get good rejection of shallow iron with minimal loss of deeper targets.
    THE GAIN CONTROL
    The gain control knob controls two things at once: the preamp circuit gain, and the software gain. The following is a simplified explanation which is not technically correct in all its details, but will serve to give a general picture how the gain control works.
    As you advance the gain control from 1 to 10, the preamp circuit gain steps through five levels of gain: xl, x2, x4, x8, and x16. On most machines (depending on minor variations in search coil alignment) you can hear a momentary blip as the machine switches from one gain level to the next. The recommended preset (marked by the triangle) corresponds to a preamp gain of x8.
    In mild ground conditions where there is no electrical interference, you may want to advance the gain control into the crosshatched region. In this region, the signal data in software is multiplied by successively larger numbers, increasing the loudness of the signals. It is somewhat similar to the "audio boost" function found on some other models of metal detectors. It's particularly useful if you're using the speaker rather than headphones and there's a lot of noise from traffic or wind, or if you're demoing the machine to someone else.
    BASIC SENSITIVITY PERFORMANCE
    Since this is a multiple-purpose machine, a U.S. Nickel coin is the most appropriate standard test target. With the gain cranked up, and in the absence of electrical interference, a nickel will typically "air test" beyond a foot using the standard 95O search coil. Your actual "air test" distance will depend on your hearing, the sweep speed, what search coil is used, how much electrical interference is present, and how you have the controls set.

    In comparison to other machines in this price range, the MXT is extremely hot on low-conductivity items. On gold, it's right in there with the more popular gold machines, being especially hot on the larger, deeper nuggets. It will compete with all comers on low-conductivity , relics and on nickels. On high conductivity coins such as quarters and silver dollars, it is still an excellent performing machine, but there are several other products in the same league for sensitivity.
    GROUND TRACKING PERFORMANCE
    The ground tracking system is nearly identical to that in the GMT, which is widely regarded as one of the best tracking systems on the market. Compared to most other trackers, the MXT has superior resolution, tracks faster, "jumps" into new ground more quickly, has greater resistance to tracking into targets, and tracks over a wider range of soil conditions. The MXT allows tracking to be inhibited if desired.

    DISCRIMINATION PERFORMANCE
    All discriminator designs are compromises. Here's how the discriminator in the MXT stacks up against other machines.
    AIR TEST "DEPTH": generally well beyond 10 inches, because of high sensitivity, with effective discrimination to within 0-3 inches of the basic air sensitivity of the target. Most discriminators will discriminate in air to within 0-3 inches of the target air depth on most targets, but most don't have the sensitivity of the MXT.
    QUICKNESS & TARGET SEPARATION: among the best, because of medium-speed second derivative ("two-filters") design. Initial field reports indicate that the MXT's mixed-mode tone system gives indication of adjacent ferrous/nonferrous targets, superior to that obtainable through discrimination.
    IRON REJECTION: Because of its high sensitivity and a slight preference in the software for not losing questionable targets, it'll be a little chattier than some less sensitive machines. Reducing sensitivity by cutting back on gain, or by reducing the threshold control setting to minimum, will help quiet it down when necessary.

    DEPTH IN MINERALIZED GROUND: Although the MXT is a two-filter system, it incorporates special techniques which reduce ground interference and which reduce the "chopping & popping" which plague most other two-filter machines. This, together with its high basic sensitivity, makes it an excellent machine from the standpoint of discrimination depth.
    FAST SWEEPING: Many discriminators tend to lose good target signals, even shallow ones, when quickly sweeping the search coil. The MXT is tolerant of moderate search coil sweeps, that is to say good at both faster and slower search coil paces.
    SUMMARIZING: The MXT has the responsiveness and sensitivity of a first-rate 2 filter machine, combined with the discrimination accuracy of a first-rate 4-filter machine.
    TARGET I.D., ETC.
    With its small medium and large blocks on the target ID screen, the ID system in the MXT bears a superficial resemblance to the "Signagraph" of the Spectrum XLT.

    It should be realized that the traditional White's Signagraph system is typically (optionally) set to accumulate data over multiple passes over a target, and displays the accumulated average. The MXT displays fresh data on each pass and scales the size of the block according to how strong the signal was relative to the ground conditions on that specific pass over the target.
    The visual ID system on the MXT is fast, easy to read, generally more accurate than the discriminator, and gives a visual indication (via block size) of how reliable the identification is. It is going to change the minds of many beeper enthusiasts who previously thought visual ID to be of little practical use outside typical coin shooting.
    CASCADE
    THE CASCADE OF EFFECTS OF GROUND BALANCE SETTING: In order to know what the ground balance setting is; flip momentarily to the gold program if you were in another mode.

    Electronic ferrite material and most "negative hot rocks" (cold rocks) will usually read in the 75-88 range. Most soils will read somewhat lower. Readings will almost never go below 25 except in salt or moist alkali soils. When readings indicate smaller numbers than 50 you may notice some reduction in sensitivity. Below 35, some rusty iron may give unpredictable responses. Below 25, iron objects may give unpredictable responses and/or may disappear entirely and the sound on nonferrous objects may become slightly more abrupt.
    MANY THANKS
    To Kenneth White and Alan Holcombe for having sufficient confidence in me to put food on my table through the good times and the rough times on this project. To Jimmy Sierra for having the patience to argue with me about all the stuff that needed arguing about, for being so passionate about the need for this product, and for being willing to compromise when that's what it took to keep the project moving. To Larry and Sue Sallee, for their personal hospitality and for field testing prototypes. To Keith Zorger, Randy Smith, Mike Brighty who field-tested and helped develop the MXT. To Bob Canaday, for being such a competent technical/engineering liaison, doing a lot of not glorious but necessary work well and managing the project during its sometimes difficult phases. To Rick Maulding, for overseeing the project, for technical contributions to the discriminator and to the salt system, and for committing White's engineering department's finest minds to engineering review during the "slow SAT isn't hot enough" crisis, which led to a major system revision that made the whole machine better. To John Earle and Dan Geyer, for diligently hacking away at problems until they became non-problems. To Steve Howard and Pam Godell of White's. There were other people involved in this project whose contact was primarily or exclusively with White's and not with me. The risk of printing credits is that one may inadvertently omit a name that belongs there; so, if I missed someone whose name belongs on this list, I'm sorry, it was an unintentional oversight. - D.E.J.
    P/N 621-0468 published 8/2002 by White's Electronics
     
  • Steve Herschbach
    The Chisana area of Alaska was the site of the last major gold rush in Alaska in 1913. As a young man researching areas to look for gold I found a reference to this remote location in the Wrangell St. Elias Mountains. It is accessible only by air and for short periods of time each year. I started visiting this area in the early 1970's and then off and on again over the decades that followed.
    The area is high above treeline and frozen for most of the year. It was mined with simple shovel into sluice box type operations along the creeks followed up by hydraulic mining on bench deposits. The remote location, lack of water, short season, and generally small area of the gold deposits meant this district never saw anything more complex than hydraulic mining operations. In later year operations have been confined to smaller scale hand operations plus gold dredging and metal detecting.
    I told a couple stories about this area as part of my Steve's Mining Journal but kept fairly low key about the location. This was mostly because the claim owners were not looking for publicity. However, the mine owners decided to sell a couple of their claims. They had to advertise them to sell them. That in turn gave me the excuse to finally tell more about my visits to the place over the years, and to share the many photos I have of this rather unique part of Alaska.
    I am telling the tale as part of an on-going episodic thread on the Detector Prospector Forum - The Chisana Story - check it out!

    Steve Herschbach with gold creviced from bedrock at Chisana, Alaska
     
  • Steve Herschbach
    This section focuses on gold prospecting for individuals and small time operators. Equipment used may include metal detectors, suction dredges, gold pans, and sluice boxes. You will find articles here to help you for both beginners and pros. There is location information,  equipment reviews, and more.

    Steve's Mining Journal - Real life gold prospecting and metal detecting stories spanning over 40 years.
    Gold Prospecting & Metal Detecting Guides - Basic and advanced information to get you started.
    Recreational Mining Sites, Parks, Museums, etc. - Locations available to the public to look for gold and other rocks & minerals.
    Where To Prospect For Gold - How too locate your own areas to look for gold in the United States.
    State Specific Information - General gold locations, geology, and history.
    Mining Claims For Sale in Alaska - Mining claims and leases in Alaska that are being offered for sale.
    Gold Prospecting & Metal Detecting Library - Online books and other reference material about gold prospecting and metal detecting.
    Steve's Guide to Gold Nugget Detectors - updated now for over 20 years, Steve gives honest opinions regarding various metal detectors past and present.
    Steve's Reviews - Equipment reviews focused on metal detectors for gold prospecting, much more in depth than the previous summary.
    Detector Prospector Forums - Forums on metal detecting for gold, gold panning, rocks & minerals, gold dredging, geology, plus coin, relic, jewelry, and meteorite detecting.
    Metal Detector Database - Metal detector feature and specifications database with user reviews.
     
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