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14x9 Evo On GPX - Is It Working Right?


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That seems shallow to me as well. 2.5 grams is a fairly good sized chunk. I've never measured any recoveries so I couldn't give you any objective observations on how deep that coil should pick up that size of nugget.  I have recovered a couple of ounces of nuggets with that coil of various sizes and, subjectively, I would say that seems shallow to "just barely hear it". Do you have a nice stable threshold in those settings? You're not set to "Quiet" under "audio settings"? 

Give it a try in Enhanced.   

Dean

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Completely depends on the nugget and the timings selected. Gold detectability varies a lot due to size, shape, and purity. Further, all PI timings have weak areas near the ground balance points in the timing schemes referred to as “holes”. Any nugget that’s composition puts its signal near one of these holes will have a weaker signal.

Comparing nugget signals is a waste of time. The best you can do if you think your unit is defective is compare depths with the same coil and exact same settings on a nickel with somebody else that has the same rig.

I get the idea you are new to PI and think they “go deeper” than VLF detectors. The reality is more like PI detector’s lose less depth in highly mineralized ground. In many Alaska low mineral / small gold situations there is honestly very little benefit in running a PI beyond the ability to run oversized coils. The vast majority of the gold found at the Ganes Creek pay to mine operation while it was running was found with VLFs like the MXT or X-Terra, not PI detectors.

I very much doubt there is anything wrong with the detector - GPX machines are highly reliable. Coils do have more variability though and it’s hard to rule out coil issues with any detector.

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9 inches air test on a 2.5 gram piece is typical using the 14x9 coil.

I only get 11 inches on a 4.5 gram piece using a 12" round EVO in Fine Gold. Get the same on the GPZ 7000 in Difficult.

As Steve said, a PI will lose less of this depth in mineralized ground over a VLF. I can only get about 3-4 inches maximum on a VLF in my hot ground.

The PI will punch much deeper, if 11" in air, I would probably get 9-10"+ in the ground. The air test is always the best case scenario for depth for all the people that think air tests are not important. They also tell you if your machine is working correctly vs other machines on the same settings. ( or for comparing depth increases on coils)

-Don

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40 minutes ago, Don71 said:

9 inches air test on a 2.5 gram piece is typical using the 14x9 coil.

I only get 11 inches on a 4.5 gram piece using a 12" round EVO in Fine Gold. Get the same on the GPZ 7000 in Difficult.

As Steve said, a PI will lose less of this depth in mineralized ground over a VLF. I can only get about 3-4 inches maximum on a VLF in my hot ground.

The PI will punch much deeper, if 11" in air, I would probably get 9-10"+ in the ground. The air test is always the best case scenario for depth for all the people that think air tests are not important. They also tell you if your machine is working correctly vs other machines on the same settings. ( or for comparing depth increases on coils)

-Don

Im not air testing. Im using dirt

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3 hours ago, bado1 said:

That seems shallow to me as well. 2.5 grams is a fairly good sized chunk. I've never measured any recoveries so I couldn't give you any objective observations on how deep that coil should pick up that size of nugget.  I have recovered a couple of ounces of nuggets with that coil of various sizes and, subjectively, I would say that seems shallow to "just barely hear it". Do you have a nice stable threshold in those settings? You're not set to "Quiet" under "audio settings"? 

Give it a try in Enhanced.   

Dean

Super stable i mean i let it purr. I can g

Hear a nickle 12 13 inches down just fine

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1 hour ago, Steve Herschbach said:

Completely depends on the nugget and the timings selected. Gold detectability varies a lot due to size, shape, and purity. Further, all PI timings have weak areas near the ground balance points in the timing schemes referred to as “holes”. Any nugget that’s composition puts its signal near one of these holes will have a weaker signal.

Comparing nugget signals is a waste of time. The best you can do if you think your unit is defective is compare depths with the same coil and exact same settings on a nickel with somebody else that has the same rig.

I get the idea you are new to PI and think they “go deeper” than VLF detectors. The reality is more like PI detector’s lose less depth in highly mineralized ground. In many Alaska low mineral / small gold situations there is honestly very little benefit in running a PI beyond the ability to run oversized coils. The vast majority of the gold found at the Ganes Creek pay to mine operation while it was running was found with VLFs like the MXT or X-Terra, not PI detectors.

I very much doubt there is anything wrong with the detector - GPX machines are highly reliable. Coils do have more variability though and it’s hard to rule out coil issues with any detector.

I can hear a nickel 12 13 inches down its not screaming nor is it quiet its almost on the edge of quiet. Keep in mind all targets are buried

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Which way the nugget is laying in the ground, the shape of the nugget, soil conditions, even the purity of the nugget will all effect how deep you will get a particular piece of gold. Dave
http://www.detectorprospector.com/forum/topic/2149-some-gold-nugget-vdi-numbers/

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