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Date Posted: 14:34:13 03/17/02 Sun
Author: Ralph
Subject: Goldmaster GM-3 and 4B --- Repost of Older Review

WHITES GOLDMASTER 3 & 4B REVIEW
By Ralph Bryant

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This information was transfered from an earlier post at http://wwwboard.net/bbs1/NuggetShooter's/wwwboard.sht for the benefit of those considering either machine for gold prospecting work

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I won't make any excuses for these units. The GM-3 is my personal current favorite of the batch, and the one I use the most myself. One of the features not noted in the earlier specifications is the variable frequency shift capability of this and the newer Goldmaster 4/B model, a handy item to have when working in close proximity to other GM units, as they all have the same "base" operating frequency of 50 kHz, and with that frequency being crystal controlled or "locked" on the different models, cross-talk can be a major pain in the butt if you don't use the frequency shift feature around other GMs.

Another thing I like about the newer models (GM-3 and 4/B) is the 10-turn threshold control. This seems a bit "over-engineered" at times, but it sure helps keep a steady and more precise audio threshold level.

The audio boost feature of the two latest models also proves a big advantage in some situations in amplifying the target audio by 300 or 500 percent over the standard setting. This helps with signals from smaller and deeper targets which may give just the slightest whisper of a signal to begin with. Contrary to what the White's ads may imply about this being a gain or sensitivity boost mode, it is simply an audio amplification feature which effects only the audio signal AFTER it is processed via the receiver circuits, and has nothing to do with the actual "gain" circuits.

The variable self adjusting threshold (SAT) of the earlier V/Sat has been continued on the GM-3 and GM-4/b, the only gold detecting units currently on the market offering this feature. This basicly allows inconsistent ground mineralization to be dealt with to produce a smoother and more consistent threshold level which helps the operator to more easily distinguish ground mineralization signals from weaker "true" metallic signals, a definate plus in many areas where a simple fast or slow switchable SAT or "recovery" speed will not afford you with nearly the range of a fully adjustable SAT speed. The latest two Goldmaster units use a very slow SAT speed for their pinpoint modes, and an adjustable variable speed of 5 to 50 times faster than the base pinpoint speed.

The GM-3 and 4/B units also have had circuitry improvements over the V/Sat and GM-II in that they have a wider or more "dynamic" gain range which allows them to operate at higher gain levels without reciever circuit overload caused by highly mineralized ground conditions. The addition of the newer "Twin-D" (double-D or "widescan") coil as now standard equipment on all Goldmasters also allows for generally higher useable gain levels in most areas, even those with the worst ground mineralization.

The "discrimination circuits" of the Goldmasters (in reality a simple iron I.D. circuit) are known for their useability and lack of resultant depth loss that is normally experienced with true phase shift type discrimination circuits. Using the Goldmasters with this discrimination or iron I.D. circuit engaged results in NO depth or sensitivty loss to targets other than those the machine sees as magnetic ferrous materials.

Having had the opportunity to compare the GM-3 and the newer GM-4/B in side-by-side tests, I really saw no noticeable difference in the performance of these two machines which have the same basic circuitry, although for those who may have less experience with such manual gold machines, the electronic ramping (push-pad) ground balance system of the Goldmaster 4/B seems a little easier to use with it's 1000:1 tuning ratio range vs. the 40:1 ratio manual turn-pot ground balance control of the GM-3. Having used the 3 3/4 turn ground balance controls of the Tesoro Diablo µMax and the 16:1 of the Gold Bug for some years, the 40:1 ratio is a breeze, with the 1000:1 ratio of the 4/B being a true extravagance.

But otherwise, the basic "differences" in the GM-3 and 4/B are very minor where performance is concerned, with the most obvious being in the configuration of the control box and it's versatility or lack thereof. The GM-3 uses the older and somewhat smaller square-shaped classic type control housing where the 4/B is of the later classic style with the meter and push-pad controls contained in a separately located housing above the operators hand grip with the main housing and controls below the operators arm-cup area for better overall balance and comfort. The GM-3 configuration however allows the operator to mount the control housing at one of two locations on the rod, or the capability to hip or chest mount the unit thereby significantly reducing the weight of the coil/rod configuration to just over a pound with the standard coil. This is a definate benefit to those of us who hunt for hours on end and may otherwise begin to really feel the fatigue of the rod-mount configuration after several hours use.

The GM-4/B is also available as a hip-mount unit, but because of the addition of the meter and push-pad control housing, some feel it awkward to use in this configuration.

My preference is the GM-3 mounted on a customized chest-mount harness made of standard nylon webbing and hardware. This allows for the machine to be directly accessible from the front and affords it some added protection from falls, slips and slides down steep hillsides, as well as any light rain showers you may rarely run into in the desert goldfields.

Overall, I feel the Goldmasters are some of the better manual gold machines ever produced, and those with the patience and enthusiasm to master a good manual machine will be well rewarded. And let there be no doubt, they ARE manual machines, with the only "automatic" feature being that of the SAT or self adjusting threshold. Everything else is up to the operator (even the SAT speed), and the infinate combinations of user adjustability are what make these machines excell in areas where many of the automatic units have problems.

As an added note, if you are in the market for one of these machines, I HIGHLY recommend the larger "Gold Max" coil from White's as it offers extremely good sensitivity for it's large size and a depth advantage of 30% or more over the standard sized Goldmaster coils.

Rumor has it (as of this writing) that White's plans to discontinue production of the Goldmaster V/Sat and GM-3, so if you are interested in either, grab one while you can. Many White's dealers still have these in stock, but I wouldn't expect that situation to last for long.

Hope this information is of some help.....Ralph

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