GPX 6000 Garrett Axiom TDI 14.4v Sub Gram Targets Test

[Jeff McClendon]

I have been doing some testing before selling some PI detectors that I really like.

The testing was done on 0.75 gram lead, 0.25 gram lead and 0.1 gram gold targets using two containers of dirt from an area northwest of Phoenix Arizona and from an area south of Breckenridge Colorado. Both samples are very mineralized with both iron and volcanic material. I placed each target one inch below the surface of each dirt sample and used a ruler stuck one inch into the containers to measure coil height above the target in the dirt. Not by any means a totally realistic test, but as close as I can get right now. I was using a TDI Pulse Scan stock 14.4v battery with Reg Sniff mods, a GPX 6000 and an Axiom. Here are the results and a photo of the dirt containers.

 

 

The Arizona dirt was no problem for all three detectors to ground balance on. The Colorado dirt was another story. The TDI would not ground balance well at all on it, the GPX 6000 was noisy on it, amazingly enough the Axiom Mono coil was very quiet on that dirt and the Axiom DD coil came up with some really odd ground balance numbers on that dirt....15/03 and was a bit unstable. I was able to run the sensitivity on the TDI and the Axiom at around 85% of max before they became unstable. The GPX 6000 became unstable at Manual 7 of 10 so I could only run it at 60% of maximum. It might have been able to have even better results, but there was EMI in the area with power lines about 1/4 mile away.

[geof_junk]

Your tests also illiterate the advantages of mono coils for depth for that size targets even in those mineralized samples.

[phrunt]

Looks very competitive.  

[Jeff McClendon]

7 minutes ago, phrunt said:

Looks very competitive.  

So far on those two dirt samples with those targets I agree. Very competitive for sure. 

[Steve Herschbach]

It would have been interesting to toss the VLF of your choice into that test. I think people would find that the new multi models like the Equinox, Manticore, and Deus 2 are on par or better than the TDI overall for nugget hunting. Given that they have discrimination and the TDI does not, well, I’d only really use a TDI for beach detecting these days, and then mainly because you can turn the ground balance off, giving it some real chops as a beach detector. As far as nugget detecting goes the TDI is easily outclassed by newer PI models. Not what TDI fans ( I am one by the way) like to hear, but it has actually been that way for a long time now.

[Jim in Idaho]

My only question is why run the TDI at 14.4v? The nominal is 14.8, and the max is 16.8. I'd bet my SL would give a response to that .1 gram nugget, since it gives a response to a 1 grain piece. Granted, it's not a 6000, or Axiom, but it didn't cost me thousands, either.

Jim

[Jeff McClendon]

5 hours ago, Jim in Idaho said:

My only question is why run the TDI at 14.4v? The nominal is 14.8, and the max is 16.8. I'd bet my SL would give a response to that .1 gram nugget, since it gives a response to a 1 grain piece. Granted, it's not a 6000, or Axiom, but it didn't cost me thousands, either.

Jim

Hi Jim,

I did not say that the TDI Pulse Scan modded by Reg was running at 14.4V. I used the nominal voltage written on the Whites battery to make sure that readers  of this post knew that the TDI I was using was a big box TDI and not an SL. I charged up the battery using the stock Whites charger. Where that charger cuts off is the amount of voltage that the battery being used was charged to.

I have had an SL fry on me using jacked up batteries. I am not doing that anymore.

This was not an air test.

The 0.1 gram gold nugget target was detectable by the TDI with the Sadie coil using those settings in air testing.

This was an in the ground test using containers of very mineralized dirt with plenty of magnetite particles and volcanic material.

I did not try to make the TDI I was testing look bad. However, its single channel ground balance system could not handle those dirt samples as well as the other two detectors. 

[abenson]

Nice test Jeff. Thanks for sharing the results. Did you try running the 6000 in difficult on the Colorado dirt. Just wondered if there would be a better or worse response on those targets.

[Jeff McClendon]

Difficult vs Normal on the Colorado dirt would be my preference. However, my main concern at the place where I did the test was EMI. Normal was a bit quieter than Difficult.......go figure.

If there had been little or no EMI, I could have run the GPX 6000 at Manual 8 at least and those results would have been even better for sure. 

[Cascade Steven]

Jeff:

Thanks for the effort.  Very informative tests and definitely food for thought.