All metal modes vs Disc and depth survey

[Don Bowers]

Hi all, I live here in central Pennsylvania. Ground conditions here are not the best in terms of detecting. A common consensus here is that a typical IB detector around here can only realize about half the depth using disc modes in the ground as compared to the all metal modes. I own several Whites detectors and a Shadow X5. The problem is the same with all units that I have. Coin sized objects buried at a foot or so are detectable ONLY in the all metal mode where as in disc modes, 6 inches is about tops. I Have a Magenta PI kit detector that I put together and it goes just as deep as my $1000 units! (in the ground where is counts).

Here is a simple test: Find a small piece of ferrite loop stick 1/4 diameter X 1/4 inch long. Ground balance your unit to the piece of ferrite. In the disc or all metal modes you should NOT be able to hear the ferrite rod anymore. Put a small coin BEHIND the rod and run it over your coil. In every detector I have tried (except a PI unit) the piece of ferrite will hide the target in the disc mode but NOT the all metal mode. Does anyone know of a manufacturer who can claim that their products will NOT loose depth in mineralized ground in while rejecting only iron?

Thanks..
Don

[nikki fowler]

Re: All metal modes vs Disc and depth survey

I tried this experiment using the Tesoro Eldorado.

I found that the disc has to be lowered just a little bit more to detect. In other words, if my detector discriminates out nickels at just PAST the nickel setting, then in order to detect the nickel with the ferrit piece, the discrimination has to be set to just BEFORE the nickel setting.

This experiment was done in the air, and I am pretty sure the results would be different in the ground.

As for depth. I am not sure how deep this Eldorado can go, but I have been able to detect pennies at over 6 inches. Quarters have been found about 8 inches. I have found a rusty hammerhead at about 12 inches.

I hope this helped someone.

[Sean Goddard]

Re: All metal modes vs Disc and depth survey

I'm working on a micro controlled ground tracker and (secret bit) machine called the "Aureus" which will do what you ask.

Trouble with "motion" mode machines is the filters are like firing a bullet through jello, where the jello represents the filters. A LOT of the signal energy is absorbed by the filters.

It is nigh on impossible to stop this "absorbtion" using conventional analogue filters, but using DSP, the losses can be compensated for. Unfortunately, none of the manufacturers out there has the technical expertise (yet) to use this powerful technology properly. Even Minelab only "play" at it as far as what is possible goes.

[nikki fowler]

Re: All metal modes vs Disc and depth survey

I am a little confused here.

I know there are machines that have "auto-ground tracking", but I don't own any.

I know there are machines with auto ground balance, or pre-set. For instance, the Bounty Hunter Pioneer 101. this machine workes good at the beach. At least for lack of falsing signals. But it does not have the depth anywhere, not even at the beach. If it had the depth and sensitivety like that of other machines, it might be a good machine. I also think lots of detectorist think it's a toy also. I think it's a toy.

As for filters. I know on a basic level that passive filters work with "okay" results, but "powered" filters work a lot better.

My confusion comes from, "Why would you tell me about this really cool idea?"

I wish you success in your building of this machine. I know there are others who are far more knowledgable in this field. I wouldn't mind performing experiments for you if you wish, and if there is any kind of help that you may need, let me or others know, I am sure you will get all the help you need from here.

Hope you do have time to find treasures also.

Thanks for the information. I hope you share part of your work for some of us who would like to build it.

Godspeed.

[Sean Goddard]

Re: All metal modes vs Disc and depth survey

Try the link below if you are looking for something to build.

If you do build it and it works (uses STANDARD Tesoro coils), then PLEASE let me know.



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