Minelab GPZ 7000 A Super VLF ( Saturable Soil Tips )

[Steve Herschbach]

Not normally with PI detectors - but the whole point of this thread is that the GPZ is not a PI detector.

[AUddicted]

Yeah... I'm like, having to stay away from tree and large bush trunks because of this issue. One can miss out on gold near a tree. Unless there is a setting (like difficult ground, severe ground or something) that won't hear root mineralization?

[jasong]

A mono on a GPX will often give a signal from a good sized barrel or saguaro cactus too actually on normal or sensitive extra, just not to the same degree as does the GPZ. I've hit tree roots with the 8 and 11" monos too. The first week I tried my 4500 out I spent an hour dissecting a 10" diameter root because I thought there had to be a target in it...

 

I think it's like salty ground, the water in plants is filled with various ions the plant uses to grow and that makes the water conductive just like water becomes conductive when rain dissolves the salt in the ground. 

[Norvic]

Had a deep target with the 5000, dug down about 18"(very hard going) and struck a live tree root about 4" in diameter. Covered it back in and went straight back with the GPZ once I got it and the 5000. They both gave the signal so with pick, crowbar, axe etc dug and cut the root out signal gone, much sweating and cussing. But laying root on surface a positive signal on both detectors, but still a very broad signal. Checked out on that trees other roots that were visible in hole, no signal so cut up the part of root dug out, signal was gone. Certainly not a common occurrence with the PI`s and haven`t struck another with the GPZ as yet.

 

Obviously on cutting up root, signal had dissipated, was very moist.

[Steve Herschbach]

Yeah... I'm like, having to stay away from tree and large bush trunks because of this issue. One can miss out on gold near a tree. Unless there is a setting (like difficult ground, severe ground or something) that won't hear root mineralization?

JP indicates that coil technique may be able to help with roots http://www.detectorprospector.com/forum/topic/763-bruce-candy-technical-paper-gpz-7000-zero-voltage-transmission-zvt-explained/?p=7905