15 KHz Versus 30 KHz On Gold & Silver Coins

[Steve Herschbach]

Published on Jan 19, 2019 - Just a quick video showing the benefits of the Vista Gold running at a higher kHz and using zero gain in highly mineralised soil Here are the videos, after further testing I can confirm that the 15 kHz hits stronger on deep silver in clean Non Mineralised Soil and both are exactly the same on the gold coin at depth in Non Mineralised Soil.

 

[Northeast]

That actually answers a completely different question for me Steve.

When digging the lawn and nature strip recently the Pro-Find has often had a consistent (but not constant) tone when I get down about the 8 inch mark.  It is reddish dirt amongst river rock.

I had assumed it was sounding off on the iron content of the soil and now I know it probably was.  I wasn’t sure if pin pointers were that sensitive.  

Thanks for the vid  

[kac]

Between my AT Pro 15hz and Tejon 17?hz I found the Tejon hits better on gold and AT better on silver. With that I am guessing the higher hz are better at gold and the lower hz better for relics and coin shooting. I can't say much for depth difference as the 2 frequencies are pretty close but the Tejon tends to be a little deeper in all metal mode.

I have a Pro-Find 35, first one I had to send back for RMA in 2 months because the speaker crapped out. The replacement is horribly unstable and I need to run it at 1-3. I wasn't impressed with Minelabs customer support as they sent me an email with rma ticket and almost threatened their might be charges for replacement on the unit the first time. For something that was only $130 and their attitude being somewhat abrasive I am hesitant on buying a detector from them. This is just my opinion as others probably have good experiences but I know Garrett would never be like that and respond very quick. I have friends that had great support from Whites as well. I am suggesting that the pro-find might not be that stable in general and the mineralization or other factors may not be the issue.

[EL NINO77]

Pinpointer Profind 35 is on sensitivity 3 - equally more sensitive and has the same - more range than older Profind 25 ... at maximum sensitivity - 5 .. I have slightly mineralized terrain that is changed from often working with Profind35 on sensitivity 4-5 without any problems ... on more difficult terrains I have a sensitivity of 3-4 ... and it's ok ..

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Test:- Frequency response   - In strong mineralization ...

I tried to do similar tests of 9.6-gram silver coin :-2 pesetas 1882 Alfonzo XII .. in depth 3.5 "= 9cm
in Black sand ... very strong mineralization is 7 bar Fe3O4- measured on Teknetics G2 .. Testing Whites Spectra V3 detector and 6x4 shooter coil .., - detector settings Whites Spectra V3: best data, program Hi-pro,recovery delay 70 ,,7.5hz-12.5hz band ground filter ,optimal Rx gain= 1- 2 max..., .. DS 70-95 ...

The test was done on 3F multifrequency, but I also did the tests on separate 1F frequencies: 2.5khz- 7.5Khz- 22.5khz ... Multifrequency pointing to 3F signagraf- as good signals on 22.5kHz and 7.5kHz, ... but for 22.5kHz - no positive signal ... Practicals similarly hit tests on 1f frequencies ...- on tests on 2.5khz and 7.5khz i got nice signals ... on at 22.5khz frequency I could not get any reasonably positive result.

A similar test is repeated on 3-gram Gold ring  of  3.5"-9cm depth  in black sand.... I will see the results of the gold test ..

Due to the strongly mineralized 7 bar Fe3O4-Black Sand I used the same setting for Spectra V3 as in the silver coin test: 3F multi fa tiez 1F. Frequencies, Hi-Pro program, best data, 7.5hz-12.5hz band filter, recovery delay 70, optimal Rxgain was 1-2 ... because setting Rxgain to 5 = caused overload, Ds 70-95 ...

In Spectra at 3F multi frequency this test in the gold ring was shown as the best signals on the 22.5khz signagraf and also the 7.5khz frequency ... On the 2.5khz frequency they were practically not well signals ... also the signal control on the 3f pinpoint showed as the strongest the signal was at 22.5 khz, then 7.5 khz and the weakest response had a signal at 2.5khz ...
With the 1F Frequency Test at the frequencies, the best frequency was 22.5khz, then 7.5khz. and at the lowest frequency 2.5kzh I practically received no response to the gold ring ...

Test Summary: Using the correct frequency on the metal detector greatly affects the correct detection of the signal from the type of the subject in the ground ... The Spectra V3  in 3F- multifrequency has been shown to be the most versatile of both types of gold and silver ... in the highly mineralization conditions. In the 1.F- test, the average 7.5khz frequency showed the universal frequency - with good signals on the silver coin and  the  3-gram gold ring - on medium size objects.

 

[kac]

The first one I had was very stable, turn it on and wait till it stopped beeping and it would do as it was supposed to. Sensitivity was reasonable and I could run it on max in most areas. After 2 months the speaker died on it (it was never dropped or even submerged in water).

Got an RMA along with an email suggesting that their might be charges to repair or replace. To even suggest that when an RMA is issued under warranty bothered me.

The replacement I can barely run it at 3 in the same areas I hunt and often it just starts randomly beeping and this one now interferes with both my AT Pro and Tejon. I find it incredibly unstable. I may try to get them to replace this one next if they don't make a big fuss.

For the longest time I used a cheap Whites Bullseye that the button actually wore out so I put a toggle switch in it's place and that still works without a hitch. It just isn't water proof.

I probably should have just got the Garrett pinpointer but thought I would give Minelabs a shot as I was looking at some of their detectors. Not impressed with their service center at all and I find the company to be a little too arrogant for my taste. Just my opinion, I am not trying to offend others here.

[kac]

From Thomas Bozek:

"Please be advised that your product is now repaired and we are arranging its prompt return. If there are any costs associated with the repair, we will be in contact with you to arrange payment."

What kind of company would issue an RMA under warranty then insinuate there might be charges. The pin pointer died in 2 months of light use under a 2 year warranty and their repair sent back an unstable unit. Why would they even repair a pinpointer in the first place? It isn't exactly a $4,000 metal detector, it's a pin pointer and one that probably only costs them $30 tops to make.