Axiom 13x11 GPX 4000 14x9 Coiltek Depth Test Deus 2 Also

[Jeff McClendon]

It thawed out enough today to do a much deeper test in a semi frozen freshwater beach erosion cut using the Axiom with 13X11" Mono coil, GPX 4000 with Coiltek Elite 14X9" Camo Mono and Deus 2 9" DD coil.

I wanted to see if the pulse induction Axiom and GPX 4000 using similar settings and similar sized coils had similar performance. This is important to me since the Axiom is the new detector on the block and it sure is a joy to operate and swing. No worrying about craning my neck to see the GPX front and back panels, worrying if I have accidentally bumped a toggle switch and in the case of the 4000 with no backlight.....trying to see what the display says and then getting strapped in for the ride. None of that is necessary with the Axiom. All the controls are right in front of me to easily see and manipulate and the ergonomics are off the chart good. But how is its performance on deep coins and is that transferrable to deeper jewelry, relics and deeper gold nuggets?

Deus 2 once again, was along for the ride. It did great giving an iron mineralization reading and for checking the test area for any obvious targets and clearing them out. So, I ran it through the test knowing full well that it was way out of its league due to its 9" coil and it being a VLF.

The test was on a 0.5 gram Liberian 24K gold coin, a 5 gram US nickel and a 5.75 gram US quarter (a high conductive target)

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I dug three notches about 2" into the cut that these targets could easily fit into. I made one notch at 9" from the surface/swing area, a second notch at 13" and the deepest notch at 18".  The Fisher F-Pulse pinpointer in the photo is 9" long.

iron mineralization again was pretty high using the Deus 2's iron mineralization meter (lower left display bar graph). You can actually see the black sand on the surface of this beach and in some of the photos.

 

I started with the Axiom using its 13X11" mono coil using the Normal timing/Slow speed with sensitivity on 3 as 4 was just a little unstable for the EMI and ground conditions. Ground balanced easily and stayed fixed. Threshold was just audible.

I tested the 0.5 gram gold coin at 9" depth.  The Axiom with 13X11" coil had no problem giving a text book high/low fairly sharp audio response on all sweeps. It wasn't loud, but it was easily a no doubt Dig Me type signal for me. Raising the coil an inch or so and the target response became very iffy.

Next I tested the 5 gram US nickel at 13" depth. The Axiom responded with a solid, sharp, text book high/low response on all sweeps. Again, these responses were not loud, but they were very obvious, no doubt responses.

I moved the 5 gram US nickel to the 18" notch. The Axiom responded with a smooth, broad, one way low/high response swinging from right to left. The response swinging from left to right was much shorter and mostly a higher tone. I could have mistaken this response for shallow ground noise, but since it was very repeatable I probably would have dug that target.

The US quarter at 18" had a similar but fainter response. Digging that target........maybe.

I then did the same tests with the GPX 4000 running in Normal/General/Slow with gain on 10 and with the threshold barely audible. The Coiltek Elite 14X9" Mono coil was very quiet after doing a frequency scan and ground balanced easily and stayed that way throughout the testing.

The 9" deep 0.5 gram gold coin sounded sharper on the GPX. The response was high/low as expected but it was a bit more clearly defined and obvious than on the Axiom. Digging that response all day. Raising the coil about 1" resulted in a very iffy response.

The 13" deep 5 gram US nickel also sounded a bit sharper and clearer than the Axiom, but the overall high/low response actually seemed to have less volume/signal strength.

The nickel at 18" did not have a broad response like the Axiom. It was very short and faint, but clearly something under the coil. Much softer response than the Axiom.

The 5.7 gram US quarter had a similar response at 18" with just a quick rising tone above the threshold.

Deus 2 using its 9" coil running FMF Goldfield, no Disc IAR, sensitivity 95, reactivity 2, audio response 4 could barely hit the 9" deep 0.5 gram gold coin and I mean barely. Without headphones, I would not have heard that response or even looked at the display for a possible target iD. Understandably, it could not hit any of the deeper targets. No mode could hit them. I expected that so no surprise.

Once again, the Axiom really held its own against a fine pulse induction detector like the GPX 4000 setup similarly.

[Jeff McClendon]

Some of the audio characteristics as far as sharpness and clarity differences between the Axiom and GPX 4000 may come down to the wireless headphones being used in both the small and larger target tests.

I am using a set of Quest wireless headphones and transmitter with the GPX 4000.

I am using the Garrett MS-3 Z-Lynk wireless headphones with the Axiom.

I don't care too much for the MS-3 Z-Lynk sound quality and that may also be slightly skewing the audio results in these two tests.

[FishBamboo]

Wow that was quick. Thanks for sharing your test results. As always I find your tests very informative. Good comparison and well done.  👍

[EL NINO77]

Thanks for another interesting test...Jeff ...

....as well as your thoughts on how the tested detectors performed on the targets...

  It was also interesting for me to compare the low-conductivity 5-cent Nickel and the high-conductivity Quarter on American coins... it can be shown, in my opinion, that both Axiom and GPX detectors are somewhat optimized for low- and medium-conductivity targets such as gold... even though they don't have a problem and they can also detect a highly conductive target like Quarter...

Furthermore, it turns out that VLF detectors definitely have limits in such a field...and the use of a PI detector can really help there.

I see this area as a very good place for testing VLF detectors... because here you can very quickly see differences in how different models of VLF detectors work on such complex targets....

[palzynski]

Yes thank you Jeff for this excellent test.  It shows that a PI can detect a 5g coin with a no doubt response at say 13-14" ( 33-35cm ) depth in a mineralized soil.

I wonder what would have been the results for the same coin in mild soil ..  I suppose they would have been similar to yours in mineralized soil  : 33-35cm which is much deeper than what can do a VLF ( 10"  25cm max for a 5g coin in mild soil from my measurements  )   , which means 40% deeper  .. without iron disc of course

[strick]

7 hours ago, EL NINO77 said:

Furthermore, it turns out that VLF detectors definitely have limits in such a field...and the use of a PI detector can really help there. 

Enter the AlgoForce E1500 with target ID.... this may be a big help for relic hunters in tough soil...

strick 

[EL NINO77]

When we tested  various VLF detectors for a small 18.5 mm -3.2 gram nickel coin in a very light forest terain /mainly sand terain/... the best detectors there reached a depth of correct detection for a weak but still repeatable good signal somewhere on the border of 34-35 cm. ..

the total detection range of the various detectors was from 26 cm as the weakest result, for other good detectors on 9" coils, 11-13" coils the detection range was somewhere at the level of 29-30-32 cm depth of detection..but they are almost an ideal detection environment from the point of view of depth of detection..

That's why it's always interesting for me to see Jeff's tests of his detectors in his heavily mineralized terrain.... which can really change the depth results of different detectors...

 

[Jeff McClendon]

Yes, only certain PIs with the right coils are going to hit 13 to 18" 3 to 5 gram targets whether the soil is mild or mineralized from my experience.

Not disturbing the soil very much when conducting the testing really helps too. I am lucky that I have that nice erosion cut for testing that is within 10 miles of my home and EMI is reasonable most of the time for PI and high gain SMF VLF detectors.

It is not as good as inert sand but it gives me some fairly realistic results give or take an inch to 3 cm.

The latest simultaneous multi frequency VLFs with very little filtering can easily hit 10" 3 to 5 gram targets at this site and even have good IDs using 11" coils. They can go a bit deeper but IDs are unpredictable.

[palzynski]

1 hour ago, EL NINO77 said:

When we tested  various VLF detectors for a small 18.5 mm -3.2 gram nickel coin in a very light forest terain /mainly sand terain/... 

the total detection range of the various detectors was from 26 cm as the weakest result, for other good detectors on 9" coils, 11-13" coils the detection range was somewhere at the level of 29-30-32 cm depth of detection..but they are almost an ideal detection environment from the point of view of depth of detection..

 

3.2 gr is a little coin , on my tests which use a little mineralized soil my results are rather 20 to 23cms depth on such a coin and I have tested  a lot of detectors too ..  Only a 10g coin would be detected at 30cm on my bed tests .

You probably have an extremely low mineralized soil at your test location 

[EL NINO77]

"Golden Forest "-extra mineralized magnetite terain-- 6-7 bar  Fe3O4 mineralizacion  measured Teknetics G2..

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.....Alain, you are definitely using a test box that already has a moderate degree of mineralization... and therefore your results will be 20 or maybe even 25 percent less than it would be in the case of a test box with pure silica sand..
This only indicates how the depth of detection can change in a different type of terrain...

Since I myself have and use my low-mineralized test field, I can accurately assess the real range of various detectors in my test field... even a very deep 25 mm coin such as 50 eurocents is stably and regularly detected with good detectors with large 13"-15" coils on 38-39cm deep, which is 15.5" inches... Really amazing results..

But my colleagues have another 5-6 different mineralized.. test fields.. and there the depth of detection changes quickly according to the level of mineralization of the terrain..

since we also have an extra strongly mineralized terrain "Golden forest" .. it is at least at a similar level to Jeff's, it is really good to see how the results of his test really turn out to be similar to our results of the test of various vlf detectors .. or PI detector ..