Ground Causing Constant Oscillation On The GPZ

[jasong]

I'm not sure if it's coincidental but since the update I've run into a number of areas that cause a strange oscillation on the GPZ.

Basically, I can set the coil on these pieces of ground and not move it at all and it will just go "wee-woo-wee-woo" constantly and loudly as if there is a target underneath, it never balances out, manual or auto. Rebalancing over the ferrite does not seem to affect it, wether the ferrite is over that spot or away from the spot. 

At first it was small spots and I thought it was EMI related, but now I've found entire washes that do it, yet the next wash over is fine. I was inclined to think it was due to salt, but there is so little salt around here that I went ahead and tasted some of the dirt (yep) and it wasn't salty. Usually I can taste salt if its bad enough to interfere with my machines. These washes have a lot of black sand and a lot of banded iron formation chunks laying about. usually running in normal and switching to difficult takes it away for the most part but sometimes it's still there.

Just odd that it never balances out. Has anyone else run into ground like that before? Most bad ground won't sit there and oscillate if you stop moving the coil even if its bad enough to not balance out.

[nvchris]

The only thing I've seen that remotely resembles at least part, is the metal foil label on aftermarket skid plate. 

 

Somehow I can't see you not aware of this though, your one of the sharper knives in the draw  

 

That said have you cleaned out the coil cover?

[Tortuga]

Come to think of it, I don't think I've run Normal soil setting much at all since the update. Just seems too hot and noisy for where I detect. I used to run it all the time, not anymore tho.

[Sourdough Scott]

I had it happen on 2 instances. One was a low flying airplane. The other instance was unknown. I shut down and went through the GB procedure and was fine.

[flakmagnet]

Jasong

 

that question by Chris might be a clue.

I have read that the 7000 coil cover collects a lot of fine dirt.

[jasong]

I clean my coil cover out pretty regularly, it's a necessity working AZ washes. This problem is definitely ground related though, there will sometimes be just little 2ftx2ft patches that I can set the coil down on and it will just oscillate, move the coil away to another piece of ground and no problem, set the coil back there, same problem. I've even revisted patches and washes and then hit the same spot and it started oscillating again right there and no where else, and I just go "oh yeah, this place again"... 

 

I'll video it next time I run into it. Resetting the machine and reground balancing does get rid of it for about 15 seconds, then it starts doing it again. The machine will work fine if I move away from these specific spots, walk back over and the same thing starts happening again though.

 

It's just in this one area that I experience it, no where else (so far). And even within this area the detector works fine in most spots, it's just specific patches of ground that seem to cause this. Very odd, to be more clear its by no means a common thing just a minor annoyance in spots, I was curious if anyone else experienced the same thing though.

[nvchris]

Hmm, your describing magnetic resonance oscillation.

 

 

Am I correct that the GPZ detection field is created by polarity switching?

[Norvic]

Had that occur on odd ocasions with the Xs but not with the Z, no matter of tuning would get it out, then it would just go, was told it is probably low ground seeking radar from a close Air Force site. Same symptoms would give an oscillating "hum" even with coil stationary. Can sort of simulate it by having a Deus close even if off, in the Deus`s case probably the coil looking for the remote.

[jasong]

Heh I read over the GPZ patents till my eyes bled before it's US release here, still not sure I understand how it works exactly Chris. 

 

Norvic, there are military bases and various other sites all over the place in the desert SW where I am at so certainly can't rule that out. But it seems like others would be reporting similar issues if that was what was happening? Maybe they are, dunno, figured I'd put this post up and see and maybe figure it out.

[spencer@wy]

Good post, i like a good mystery!

My hypothesis is that certain ground minerals are acting as an external antenna for the machine, allowing for augmented reception.