By Steve Herschbach
I do what I can to foster competition that develops alternatives to the all too common VLF detector. There are plenty of options out there, but in my opinion they all weigh too much or cost too much. Usually both. I envision people out there with a popular VLF metal detector for beach, relic, or gold detecting. These machines all sell for around $700 and weigh 2.5 - 3.9 lbs. Perhaps they would like to add a ground balancing PI (GBPI) to what they have. I think that for "normal people" with normal budgets a machine under $2K and under four pounds just makes sense. It would be more than twice what they spent for their VLF, and in this day and age there is no reason why a decent PI should weigh over 4 lbs. To clarify what I am talking about here, I should say that for many people a $700 VLF detector is a great place to start and in many cases is all a person ever needs. However, there are places where extreme ground mineralization and mineralized rocks (hot rocks) severely impede the performance and use of VLF detectors. Alternative technology to deal with these conditions has been developed, by far the most familiar being the Minelab ground balancing PI (GBPI) detectors. These differ from common PI detectors by having the ability to ground balance. Other brands have offered the Garrett Infinium (discontinued) plus Garrett ATX and the White's TDI models. These detectors are used not just for gold prospecting but also by relic hunters, beach detectorists, and others who face challenges regarding ground mineralization and VLF detectors. Frankly, in my opinion GBPI technology is largely maxed out. The main room for improvement comes now in better ergonomics at lower prices. This challenge therefore limits detectors to those that weigh under 4 pounds with battery included, and which sell brand new with warranty after discounts for under US$2000. Detectors need not be ground balancing PI models, but must offer similar ability to ignore mineralized ground and hot rocks that trouble VLF detectors. I am going to rate detectors as to their relative performance using what I call the "Minelab Rating Scale. Details here.
1. Minelab SD 2000 - crude first version, very poor on small gold, excellent on large deep gold
2. Minelab SD 2100 - vastly refined version of SD 2000
3. Minelab SD 2200 (all versions) - adds crude iron disc, ground tracking
4. Minelab GP Extreme - adds greatly improved sensitivity to small gold, overall performance boost.
5. Minelab GP 3000 - Refined GP Extreme
6. Minelab GP 3500 - Greatly refined GP 3000, last and best of analog models
7. Minelab GPX 4000 - First digital interface, rock solid threshold
8. Minelab GPX 4500 - Refined GPX 4000, solid performer
9. Minelab GPX 4800 - Released at same time as GPX 5000 as watered down version
10. Minelab GPX 5000 - Culmination of the series, current pinnacle of GBPI prospecting machine technology.
All Minelab models leverage an existing base of over 100 coil options from tiny to huge.
I am a very practical person when it comes to detecting. I know all the existing models and options by all brands very well, perhaps better than almost anyone. This is the way I look at it is this. If I personally were to spend a lot of money to go gold prospecting for one month, and needed a GBPI detector, considering machines past and present, what would I get and in what order of choice? Put aside concerns of age, warranty, etc. just assume functioning detectors.
Here is the issue in a nutshell. On the Minelab scale of one to ten as listed above, I would be generous in rating the White's TDI SL as a 2. Same with the Garrett Infinium which I will mention in passing as it is no longer being made. If I was going to spend a month of my time and a lot of money going on a prospecting trip, I would choose a TDI in any version over the SD 2000. I might go with a TDI Pro over a SD 2100 but I would have to think real hard about that, and when push comes to shove I would go SD 2100 were it not for the realities of age I said to ignore. A newer TDI Pro might be a better bet than a very old SD 2100 from a reliability standpoint, but again, this would be a tough choice. The TDI SL not really. In my opinion I would be shooting myself in the foot to go on this hypothetical trip with a TDI SL instead of a SD 2100.
You see the problem now?
The Garrett ATX fares better. I would rate it a 3, roughly analogous to the SD 2200 variants. Still an agonizing choice really and the ATX being new versus SD 2200 being old might again be the tipping point, but from a pure prospecting options perspective the case can be made that the SD 2200 might be the better way to go. The problem for this challenge is the ATX weighs way over 4 lbs and sells for slightly over $2000. The price is close enough really but the 7 lb weight is way off.
That's it folks. That is reality. The best of the best that the competition can offer can only go solidly up against models Minelab has not made in years. I am not saying that to be mean or as some kind of Minelab toadie, that is my pure unvarnished opinion as a guy who is pretty well versed on the subject.
Let's bring it all home. This person with the $700 machine really, really wants that under 4 lb, under $2K GBPI machine, but if they do their homework they discover that truthfully, they would be better off shopping for a used Minelab than what the competition offers new. With the TDI SL rated as a 2 the ATX in a much lighter box at under $2K is a solid win as a 3. A well designed ATX with standard dry land coils would look very enticing as compared to the GP series Minelabs. But Garrett refuses to budge!
White's can certainly do something, anything to improve the TDI SL. A battery that lasts all day would be a good start. In the end they are limited by the basic single channel design of the machine. The SD 2000 dual channel design was literally the answer to and the improvement on the single channel technology used in the TDI, the basics of which predate the SD 2000. Still, White's currently owns the under 4 lb under $2K GBPI category so they have the first out of the starting gate advantage. Anything they do would at the very least just show they have not given up.
The Minelab MPS patent that formed the basis of the SD series has expired. Not sure about DVT, which formed the basis of the GP series. Where is the competition? What the heck is going on here? Much gnashing of teeth and pulling of hair is going on here, that's what!!!
That is my challenge to the manufacturers. Under 4 lbs, under $2K, on the 1-10 scale I am offering, what is the best you can do?
The TDI SL as a 2? Really? Yes, really, that is currently the best of the best in the brand new ground balancing PI, full warranty, under 4 lb, under $2k category. You can pick up a 3.5 lb TDI SL right now brand new for $1049. The White's TDI SL takes the crown.
Hopefully we will see more competition in this wide open category soon. I have been beating this drum for years to no avail, but I do have reason to believe we are finally going to see more alternatives soon. I hope.
By Steve Herschbach
High Frequency Gold Nugget Detector Roundup
Our cup runneth over!
Just a few years ago the market for "over 30 kHz nugget detectors" was quite limited. For a long time there were only a few options:
Fisher Gold Bug 2 (71 kHz) $764 with one coil
Minelab Eureka Gold (6.4, 20, & 60 kHz) Discontinued $1049 when new with one coil
White's GMZ (50 kHz) Discontinued $499 when new with one coil
White's GMT (48 khz) $729 with one coil
Things were that way for over a decade. Then in 2015 Makro introduced the Gold Racer (56 kHz) $599 with one coil. Sister company Nokta released the AU Gold Finder (56 kHz) $799 with two coils
Then in 2017 we see the Minelab Gold Monster 1000 (45 khz) at $799 with two coils. And although not a dedicated nugget detector, the Deus high frequency coil options (up to 80 kHz) were also released, $1520 for complete detector with one HF coil.
Now in 2018 we get another general purpose machine, the Equinox 800, that can hit 40 khz, $899 with one coil. And just announced...
the Makro Gold Kruzer (61 kHz) $749 with two coils and
the White's Goldmaster 24K (48 khz) $729 with one coil
These last two announcements have made barely a ripple in the prospecting world, or at least going by other forums that seems to be the case. There are various reason for that (forums not being prospecting oriented or being Minelab centric) but still the lack of buzz is interesting. I do believe people are both burned out by all the new introductions and that the market is saturated with high frequency models. Leaving out the general purpose machines to sum up the current options it looks like the current "sweet spot" for pricing is a high frequency model at $749 with two coils. The Gold Bug 2 saw a price reduction to $699.
Makro Gold Racer 56 kHz - $599 one coil
Fisher Gold Bug 2 71 kHz - $699 one coil
White's Goldmaster 24K 48 kHz - $729 one coil
White's GMT 48 khz - $729 one coil
Makro Gold Kruzer 61 kHz - $749 two coils
Minelab Gold Monster 1000 45 kHz - $799 two coils
Nokta AU Gold Finder 56 kHz - $799 two coils
Added 1/2019 XP ORX up to 81 kHz - $899 one coil
High frequency nugget detectors compared
White's Goldmaster 24K, Minelab Equinox 800, Gold Monster 1000, Makro Gold Kruzer
Minelab Gold Monster, Fisher Gold Bug 2, Makro Gold Racer, Nokta Impact
By Steve Herschbach
The White's Goldmaster 24K is a new 48 kHz gold nugget detector released in the fall of 2018. Production models started shipping in September and White's forwarded one to me to check out. What follows are my thoughts after a couple days of detecting for gold on several northern Nevada nugget patches.
The Goldmaster 24K marks a break with the past as White's moves from the older metal box designs of the past to newer plastic cases. The Goldmaster 24K physical design is the latest in the evolution of the MX series. The control box itself is derived directly from that used on the White's MX5. The control pod / display originated with the TreasurePro and later used in the MX Sport and MX7 designs. Basically the Goldmaster 24K is in the same housing and rod design as the White's MX7.
Manufacturers face a difficult design choice these days. In general users want metal detectors to be as light as possible. However, weight is not everything - balance matters every bit as much. The problem is that a metal detector search coil is basically a weight on the end of a long stick. Coils can only be made so light due to engineering constraints requiring a certain amount of copper wire and a reasonably robust coil housing. The coil then has a lot to do with determining the final ergonomics of the detector. If the coil weight is not balanced at the other end with some kind of offsetting weight, the detector is nose heavy. This in turn creates torque everytime the detector changes directions which puts stress on the operators arm.
The detector can be made as light as possible, or can be perfectly balanced, but it is almost impossible to do both in one detector. Any detector that weighs less than 3 pounds is almost certain to be nose heavy because enough weight does not exist to balance the weight of the coil. In order to have enough weight to work with it appears the minimum is about 3.5 lbs for detectors that are well balanced. The extra weight is almost always in the form of a battery box located under the elbow. White's has gone this route is the MX series designs with a battery box holding 8 AA batteries under the elbow acting as a balancing weight. This results not only in a well balanced detector but a detector with enough batteries to operate for multiple days between charges or battery changes.
White's Goldmaster 24K metal detector for gold prospecting
Another big choice manufacturers have to make these days is whether to use a straight rod or a "S" rod design. Users tend to be evenly split as to which they prefer, and so this is a choice the manufacturer cannot possibly win. About half the people are going to be unhappy whichever way you go. Industrial type users like beach hunters and prospectors tends to prefer straight rods. Coin, jewelry, and relic hunters seem more inclined to "S" rods. I have used many detectors with either setup and have been happy with both or unhappy with both. The deciding factor for me has been more about the exact size, shape, and angle of the hand grip than the actual rod design. I do not have over-sized hands, and so I tend to prefer a smaller diameter grip. Other people like a larger grip.
I went into all that detail to be sure the reader understands that weight and balance is very much a personal preference item. Getting a detector to fit right for everyone is like making a pair of boots that fits everyone. You can't do it. Therefore when I say that the MX physical design as employed in the Goldmaster 24K is a very good fit for me don't take that as meaning it will be great for you. Yet it is a very good fit for me and quite comfortable on my arm, with just enough forward weight to keep my elbow in the arm cup without having to use the arm strap. The design is also lighter than the White's GMT by nearly half a pound, so the Goldmaster 24K is both well balanced and lighter than what came before. The Goldmaster 24K with 10" elliptical coil and with batteries installed weighs 3 lbs 7 oz (3.4 lbs) or 1562 grams on my digital postal scale.
The Goldmaster 24K has an IP54 rated enclosure that has a high level of protection against dust particles, and a fair amount of protection against water. The coils are waterproof but the detector itself is not submersible so keep that display pod out of the water. The "S" rod is a three piece design with excellent quality twist locks that create a firm, wobble free rod assembly when fully engaged. The armrest position is not adjustable but it is well placed.
The 24K is powered by eight AA batteries in a battery holder that pops out of the rear of the battery box. The 24K is supplied with eight alkaline AA batteries but rechargeable batteries may be substituted for use in the battery holder. The 24K can get up to 40 hours operation using high quality alkaline batteries and while using headphones (external speakers use more power). The Goldmaster 24K does have a speaker built into the rear of the display pod, and there is a female 1/4" headphone jack directly above the battery door. White's thoughtfully includes a small plastic plug to insert into this hole when not in use.
White's 24K battery holder and headphone jack location
The Goldmaster 24K comes with a 5.5" x 10" DD coil as the stock coil. A 6.5" round concentric coil is available as an option. Scuff covers for the coil are not included with the detector or when you buy an accessory coil - they are separate optional items.
The 5.5" x 10" DD search coil weighs 14.5 oz or 412 grams. The coil is 1" thick. The 6.5" round concentric coil is 3/4" thick and weighs 13.1 oz or 370 grams. Therefore the 24K when outfitted with the 6" concentric weighs in at 3 lbs 5 oz (3.3 lbs). White's possibly has a 13.5" x 8" DD available soon that weighs 1 lb 8 oz or 682 grams. Finally, a version of the 4" x 6" Shooter DD is in the works also. Neither of these coils is available for sale as of March 2019 so for now the GMK has one accessory coil (the 6" concentric) available for purchase. Do note that all pre-existing coils for other White's Goldmaster or GMT models are not compatible with the Goldmaster 24K. The 24K pumps about 50% more voltage to the coils than previous models, requiring tighter tolerances in the new coils. The coil connector has been changed to prevent confusion.
5.5" x 10" DD search coil and 6.5" round concentric coil for White's Goldmaster 24K
The Goldmaster 24K shares many functions with the White's GMT model but there are differences. The most obvious being that the GMT uses knobs for control adjustments. The 24K uses a sealed touchpad which is more water and dust resistant, but some controls have secondary functions that necessitate having the Quick Guide near at hand when learning the detector.
The 24K like the GMT does of course have a sensitivity control, and like on all hot VLF detectors it is a critical control. The solution to most problems regarding metal detector instability or interference is to reduce the sensitivity.
The 24K features both automatic ground tracking or a fixed ground balance adjusted via a tap of a "ground grab" button - in this case the pinpoint button, which doubles as a ground grab when given a quick tap. Ground tracking can be a great function for variable ground and people new to detecting. Personally I prefer to lock the ground setting (via the "Lock" button) and update it manually via the ground grab function. I did use the ground tracking however, just to try it out. It is lightning quick, taking just a pump or two to track into the ground. Ground grabs are instantaneous.
The White's GMT allowed for a locked ground balance to be tweaked up or down manually via plus or minus buttons on the control pod. The 24K takes a slightly different route by allowing a "ground balance offset" to be dialed into the detector. The ground balance offset is a powerful feature and so deserves some explanation. Prospectors often prefer manual ground balance because they can choose their own setting that for various reason might be different than what a machine will choose using a preset function like ground grab. Ground grab may be set to deliver a very neutral ground balance. The prospector may prefer that the balance be slightly positive to help enhance tiny nugget signals. They may want to choose a ground balance setting halfway between the ground itself and some pesky hot rock, which may mean adjusting either positive or negative from the neutral setting. This might require that the operator first do a ground grab, then hit the plus button a couple times to manually offset the ground balance.
The 24K has a "Follow The Black Sand" mode like on the GMT but it is now called Ground Scan. Ground Scan is enabled by pushing and holding the ground balance "Lock" button. While in Ground Scan the "Up" and "Down" buttons create a ground balance offset. This offset is retained when you leave Ground Scan mode and will be applied both when doing a ground grab and even while in ground tracking mode.
The Ground Scan / Follow The Black Sand thing is intended to allow a prospector to locate and trace shallow magnetic sand deposits that might indicate potential gold concentrations. This is a rarely used function, but including the offset ability means this function may be accessed much more often just to create these ground balance offsets. With the GMT you could ground grab and then manually tweak the setting, but the tweak had to be applied every time the ground grab is performed. Now the offset can be dialed in and automatically applied. The real zinger however is that this also allows the 24K ground tracking function to be directly tweaked - very, very rare indeed. Almost every detector I have ever used has a preset ground tracking circuit that puts the ground balance where it wants, end of story. With the White's Goldmaster 24K you can create a tracking offset to deal with hot rocks in a way that simply can't be done with most other ground tracking systems. Really cool White's!
White's Goldmaster 24K with 13.5" x 8" DD coil (prototype lacking decal)
The 24K has the volume control the GMT lacks which is quite handy for those who want to run without headphones but not necessarily at full volume. There are 8 levels of volume plus two boost settings, Boost 1 (b1) and Boost 2 (b2) that kick in when you adjust the volume control above 8.
The GMT features a Variable Self Adjusting Threshold (V/SAT) control that governs the rate at which the audio resets itself when passing over a target or ground variations. The GMT has a knob that runs from 1 to 10 and on the Goldmaster 24K the SAT setting has been simplified to three settings - off, medium, and fast. The default setting of medium is all most people will ever need. However, in extreme low mineral ground the off setting can enhance weak signals, although the detector may need very careful coil control and slower coil sweeps to allow the circuit to keep up. Conversely, extreme high mineral variable ground may require the fast setting to smooth out variations in the ground signal.
The threshold control itself is interesting. Normally on an old school threshold based all metal detector the all metal mode and threshold are one and the same. The Goldmaster 24K like some newer digital models appears to employ what is referred to as a "reference threshold". The threshold may be adjusted, but appears to be disconnected from the all metal channel and is instead layered on in parallel. The SAT control above does directly affect the all metal channel as described above. Yet it does what it does whether the threshold is present or not. Reference thresholds often exist for the sole purpose of nulling or going silent when passing over items that have been discriminated out, but this does not happen when the Iron Cancel (see below) is engaged. While bench testing in all metal with the SAT set at zero I thought I might just be able to hear a waver in the threshold. I would be interested in hearing from other nugget hunting experts on this matter, because in my opinion the threshold as it exists on the Goldmaster 24K is not coupled to the all metal channel in the manner one would observe on the GMT for instance. The only effect seems to be with threshold completely off the 24K will no longer give any ground feedback at all if out of ground balance. Based purely on what I am observing in actual use I would say the 24K is a silent search detector with a reference threshold added as opposed to a true threshold based all metal circuit like on the GMT. The difference is subtle but there for my ear at least and if there is a connection there between threshold and all metal channel, it is too minimal for me to discern while in actual use.
Now we get into the real meat of where the GMT and Goldmaster 24K part ways. The GMT has an iron (ferrous) probability meter as does the Goldmaster 24K. The GMT meter is merely a bar graph - far left means 10% chance of ferrous and far right means 90% chance of ferrous. Somewhere in the middle means 50% chance of ferrous. The Goldmaster 24K puts a blacked out block at the top of the screen with similar positioning, but the actual percentage numbers display out as a "target id" number. This is not a target id number as thought of on coin detectors, but instead intended to be a display of the odds that an item is non-ferrous.
White's Goldmaster 24K controls and display screen
If you look at the display above there is a colored bar at the top of the 24K LCD meter - red on left, wide yellow middle, and dark gray on right. The three colors taper one into the other to indicate overlap. The red on the right indicates the probable ferrous range, and dark gray indicates items reading too high to probably be gold, but more likely a copper, brass, or silver item (high conductors) or certain ferrous items that "wrap around" and "read high". These include hardened steel items like large bolts, almost any washers, ax heads, etc. In theory this scale could be used for coin detecting but the coins with few exceptions like a nickel tend to bunch up all on the right. The intent really is to be more of a ferrous/non-ferrous meter but I do think I could make do with this for some general detecting scenarios. In air tests a nickel read 88, zinc penny 95, dime 96, and quarter 97.
The Goldmaster 24K has an Audio Mode button that engages and disengages something analogous to the "Iron Grunt" feature on the GMT. Engaging the Audio Mode replaces the normal VCO type "zippy" audio with a simple high or low beep. Any meter reading below 50 will deliver the low "ferrous" beep and anything 50 or higher a high "non-ferrous" beep. Since the gold probability range runs much lower this is helping the operator concentrate only on the high probability targets - anything with over a 50% chance of being non-ferrous. This "over 50% equals non-ferrous" audio mode could be useful for direct hunting in some situations. However, when pushing the detector hard in all metal mode and then switching the Audio ID mode on I found that I would have to reduce sensitivity or encounter quite a few false signals in mineralized ground. That being the case I was more prone to using this as a ferrous check by engaging the button for a quick audio reading, then back again to all metal mode.
The Audio Mode as I described it above acts much like the Iron Grunt feature on the GMT, but on the GMT the ferrous audio alert only kicks in when there is an 85% or greater chance of the item being ferrous. It is not a certainty on how the percentages correlate, but the 24K audio ferrous tone does kick in at readings of 50 and below (greater than 50% chance of being ferrous). Borderline gold targets can read lower than this however, down into the 40s and even lower. A 30% chance of gold is still pretty good odds. So what to do now except read the numbers?
White's has addressed this with another control, the Iron Cancel button. Engaging Iron Cancel activates an adjustable iron rejection setting. The default is for anything reading 15 or lower to simply not beep. This corresponds to the solid red area on the bar graph display at the top of the meter. Borderline or mixed content items will break up or give erratic readings. The best part however is that the setting can be adjusted from 0 all the way up to 62. This allows the operator to completely block out a chosen range of low end readings that is either more conservative or more aggressive than the Audio Mode preset. As noted before, the threshold, if any is used, will not blank over rejected items - they are simply ignored.
I noted above that highly conductive items and some steel items can read at the very high end of the scale, typically 95 and above. If the goal really is gold it is very unlikely that readings this high will be gold and so White's also offers the ability to block out this high end range. Tapping the "lock" button while in the ferrous adjustment mode will automatically block all readings of 94 and higher, which is where most iron high end false signals will occur.
Other controls on the Goldmaster 24K - a pinpoint function, frequency shift to help avoid electrical interference or for running two 24Ks close together, a backlight for the meter for low light conditions, and finally, a factory reset.
White's Goldmaster 24K with stock 10" x 5.5" DD coil
Now for the part everyone has been waiting for - how does the Goldmaster 24K at finding gold? When I test nugget detectors I tend to concentrate on smaller gold. First, because it is more plentiful and easier to find in limited time frames for testing purposes. Realistically small gold also challenges the detector the most. A metal detector must be tuned as hot as possible to find very small bits of gold. Yet this also causes problems with mineralized ground and hot rocks. It is not so much the small gold sensitivity that matters but how the metal detector handles the ground while tuned up for tiny gold. This is why air tests are minimally useful for nugget hunters. They can reveal theoretical information about how small or how deep a detector can find gold under perfect conditions. Air tests give no indication however of how the detector will handle bad ground and hot rocks when tuned to the max. A detector can air test extremely well and fail completely in the field. Therefore when you see my metal detector test reports, pay attention to the smallest nuggets I find, not the larger ones.
The 10" DD coil is a good all around nugget hunting coil, with DD coils having the advantage for handling difficult ground. It was the 6.5" round concentric that wowed me however and after I got it on the detector I really did not want to take it off. The 10" DD will be a better choice for really bad ground, but lacks that magic edge on the tiniest bits of gold. I also appreciate that concentric coils are easier to pinpoint with, and generally have better ferrous identification performance compared to DD coils. One nice thing about the 24K being well balanced is the 13.5" x 8" coil is less nose heavy than would be the case for an unbalanced detector. This is the coil to use for covering ground in search of larger gold nuggets.
For medium to milder ground and the smaller gold however I really do like that little concentric. In particular there is a lot of grass growing in some desert areas, and the 24K with 6" coil was perfect for mowing through the grass to keep the coil on the ground. This is another area where an "S" shaft has the advantage. A straight shaft detector wants to roll to the side when forcing the coil against resistance, where a balanced "S" shaft being in line with your arm does not produce that kind of rollover torque.
The 10" x 5.5" DD coil was a little more prone to false signals when bumped hard than the concentric coil, to the point where I could run higher sensitivity with the concentric on this particular ground. The ground in lots of Nevada is rather mild, often with alkali (salt) content, and it may or may not have bad hot rocks. This particular location had two types of hot rocks to deal with. The bottom line is I was able to run the concentric at full sensitivity of 10, and in audio boost 2 (b2) while in all metal mode and SAT set at medium (default). Even with the machine maxed out like this the detector ran well, and as I said before falsed less than the DD coil would if I attempted the same settings.
White's new XGB ground balancing system really does seem to do a good job finding a setting that works well with both hot rocks and the ground by tracking multiple ground balance points. I liked to engage tracking, run over a mix of ground and hot rocks, and then lock the setting. I was scrubbing and pretty much digging everything. The Goldmaster 24K with the little concentric is hot as a pistol and as usual if you give me a hot detector I was able to find some really tiny gold. The eight nuggets below weigh a total of 8.3 grains (not grams - 480 grains per Troy ounce). The largest nugget is 1.8 grains and the smallest are in that under 1/10th gain range. Now, none of these were super deep because you can't find tiny gold super deep, but they were all good zippy targets - and I was not using headphones!
Gold nuggets found by Steve with new White's Goldmaster 24K - smallest under 1/10th grain
The proof is in the pudding and there is no doubt the Goldmaster 24K can find the gold, and some really small gold at that. I am not going to try and convince anyone that there is some kind of magic breakthrough here - at the end of the day the 24K is a hot 48 kHz single frequency metal detector just like the GMT in many regards. Some oldtimers may still prefer the GMT for its threshold being tightly connected to the all metal channel while the threshold connection on the 24K is much weaker. Although the Goldmaster 24K can be run hot and noisy, all it's design features point to a detector that is intended to be set up as quiet as possible, and this may even mean running without a threshold. I did not see any evidence that this would really hurt the performance at all. This kind of quiet hunting tends to appeal more to people new to nugget detecting, especially those who cross over from coin detecting. Add this to the lighter weight and lower cost package and White's has done a great job producing an alternative to the admittedly long in the tooth GMT.
White's Goldmaster 24K Data & User Reviews
White's Goldmaster 24K Quick Start Guide
White's Goldmaster 24K Advanced User Guide
White's Goldmaster 24K & GMT Compared
Little gold nugget on coil fresh out of the ground
I hooked up a sensor coil to pick up the transmit frequencies from my 800. Connected to an audio spectrum analyzer I could see what was being transmitted in all the modes. Surprise, Park 1 uses only a single frequency ~ 15KHz. The amplitudes shown are relative.
Just finished a second day hunting with the new Mirage PI. Short days, I seldom go for more than 2-3 hours, but enough to start learning a new to me machine. Something I notice and wonder about. The 9.5" mono coil appears more sensitive to iron near the edge of the coil, while nonferrous seems to hit harder near the center of the coil. Could that be a thing or am I deluded? If it is a real thing, is it a reliable way to make dig decisions?
I could swear I read something somewhere about this, but am no longer sure because I am deluded in general anyway. Anyone got thoughts?