High Frequency Coil Question

[oroseeker]

I have a coil question for Randy or Old Lamar. I am a gold prospector and coin hunter. I would like to know what either of you think about the idea of Minelab or Coiltek designing and marketing a 10 inch elliptical 48 kHz or 71 kHz coil for gold prospecting? The coil can either be concentric of DD. I currently prospect for gold with the x-terra 705 in Washington state, Oregon, California, Alaska and Arizona (so many place to prospect and not enough time). I currently have the 6" DD 18.75, , 10..5 DD 18.75 and the 5" elliptical DD 18.75. I also use a GPX 4000 as well.

Anyway, I will generalize by saying that every prospector knows that there is a lot of "small gold" out there the is less than 0.5 grams or 7.7 grains and smaller (i.e. sub grains size 0.01, 0.02, 0.07 or 0.10 grains). So what I am looking for is another "tool" for my "tool box" rather than buying another detector.

I think creating a high frequency 48 or 71 kHz coil would be possible for the x-terra 705. I assume that the Minelab VFLEX technology using a 48 or 71 kHz coil can achieve the same results as the White's VLF (very low frequency) or Fisher VOC (voltage control oscillator). Currently there are only two detectors as you already know that use these single frequencies, White's Gold Master series (GMT 48 kHz) and Fisher Gold Bug 2 at 71 kHz.

In the meantime, thanks in advance for your comments....oroseeker

 

[oroseeker]

Oops! I meant to say Old Longhair not "Old Lamar". Sorry about that........oroseeker

 

[Old Longhair]

It may be possible, but I wouldn't hold my breath. I can't imagine that Minelab would allow a machine that could compete with a GPX w/o charging GPX price for it.

 

[oroseeker]

Hello Old Longhair, In my opinion, I do not think it is competition for the GPX Series. Rather competition is with the Fisher Gold Bug 2 (a +$700 or +$800 machine depending own where you buy it). Currently the Gold Bug 2 and lately the Gold Bug Pro (19 kHz) have located sub grain gold targets that are outside the detectable range of the GPX PI machines. Anyway, I think it may be something down the road that Minelab or Coiltex might consider. I think the x-terra 705 is in the right price range and I know for a fact that the coils I own for the GPX 4000 are expensive as well. So creating another $300 - $500 coil that is sensitive to small gold can have a place in the gold prospecting market. Thanks for your comment.....oroseeker

 

[glabelle]

The problem probably lies in the circuitry of the box. If it cannot handle frequencies above 18 KHz, they can't make a coil for it that will work.

I'd guess that if it could they would have offered a higher freq. coil.

George

 

[Digger]

I can't speak for what Minelab might do. But I can't see them redesigning the X-TERRA to include additional frequencies. Not only would it make the existing X-TERRAs "obsolete". They already have the Eureka Gold detector, which basically does what you are asking. It just isn't on the X-TERRA platform. The Eureka Gold is a VLF detector that operates at any one of three different frequencies.....6.4 kHz for maximum depth, 20 kHz for general prospecting and 60 kHz for small gold. You just flip the switch to change freqs.


Minelab's X-TERRA, their Eureka Gold, Fisher's Gold Bug 2 and White's Gold Master are all VLF detectors.

A Voltage Controlled Oscillator is an electronic oscillator whose oscillation frequency is determined by the applied voltage. So as the coil nears a target, an increase of voltage is sensed by the detector, thus increasing the volume and pitch of the audio response. Fisher's Gold Bug 2 advertises that functionality as VCO. However, most detectors use similar functionality that varies the volume and pitch of the audio, as the coil nears the target. White's GMT and the Minelab Eureka Gold vary both the volume and pitch of the audio signal, as the coil nears the target. The X-TERRA 70 and 705 has it in Prospecting mode and in Pinpoint of the Coin/Treasure mode.
JMHO HH Randy

 

[oroseeker]

Hello Randy, Well based on your comments, it looks like the idea of a higher frequency coil above 18.75 is "not feasible" for the x-terra 705 platform without a significant redesign. Also, it was not my intention to redesign the x-terra 705 and make the current x-terra series obsolete. I do not think anyone could sell that idea of "redesign" given the excellent track record of the x-terra series. Anyway, sometime ideas don't always give you the results you are searching for. Thanks for sharing your comments!.....oroseeker

 

[Old Longhair]

Being all digital technology, I believe that it wouldn't be too hard to do with the V-flex platform.
It would require a new machine (905?), programmed to accommodate the parameters of the additional frequency. It could be conceivably able to accept all previous Xterra coils, but the new higher frequency coil would be as exclusive to it as 3kHz was to the old XT-70.

So...
Possible? I believe so.
Probable? Not at all likely.

Minelab already introduced the "new" SDC2300 PI machine this year, and Codan's February Financial report revealed a new entry level machine coming sometime soon. I also expect that they will expand the FBS2 Smartcoil field before they invest much more into V-flex.

JMHO

 

[Digger]

I don't think it would take a significant redesign. But it would take rewriting the current software. And that alone would make the current models (in the field) obsolete.

With that said, I like your idea. And to be honest, I passed a similar idea to them a couple years ago. At that time, I had proposed adding a fourth frequency, based on the 60 kHz functionality of the Eureka. Considering the Eureka is based on the same "housing" as the Advantage and Sovereign, which are now both manufacturer discontinued, what better time to incorporate that "small gold detecting technology" into the X-TERRA platform? But like you so clearly stated...."sometime ideas don't always give you the results you are searching for." HH Randy

 

[oroseeker]

Hello Randy, Thanks for sharing again. Also it sounds like you have had this idea before. This is a good conversation and I hope in the future it will come up again!.....oroseeker

 

[oroseeker]

Hello Old Longhair, Thanks for sharing your input as well!....oroseeker

 

[tonopahkid]

Minelab did make a unit called the American gold striker ran at 32 kHz was really a nice and easy unit to use got great depth with the 11 inch coil.I also had herd the tesorso diablo was a very good gold machine.