CZ3D ground bal issue

Had a GB issue that I have never encountered before with the 3D. I was using the Fisher 10.5 coil and had to adjust the GB all the way to 10. Still, at this point of adjustment I could not hear the threshold increase when lifting the coil. At the 10 position it had just gotten to the point where there was no increase in threshold when lowering the coil, I went with this setup since this was the best GB I could get and I was at the adjustable limit of the GB pot. Same thing with the 8" coil installed. Machine ran fine(stable) and I was digging targets at 8"+ with no problem. I have always had enough adjustment with the GB pot to got past the "null" either positive or negative but not this time. My soil here is pretty nuetral, but this was a new site for me, about 100 yards from the RR tracks in an old river port town. Can anyone give me an explanation, ground minerals, iron contamination etc?? Thanks, Beach

Is this consistent site to site?

Clean/clear ground. No/low minerals. Grnd Bal not required.

Might add hunting with a buddy thought my CZ was malfunctioning until my buddy pointed to a high tension box on a telephone pole. Tom is certainly correct but just moved away from the interference and ground balanced perfect so outside interferences can cause your unit to malfunction...

This was the case over about a 2 acre site. Dan first thing I did was ck for EMI source, none that was close enough to present a problem. Tom, when you state no GB required, are you saying to just set it at the preset #5? I'm usually anywhere from 4-7 on the GB in my soil most times,



Edited 1 time(s). Last edit at 09/26/2012 04:19PM by Beach.

I would leave the GB on '10'...... if the ground is neutral.
I have the same conditions here in Florida whereby...... the dirt and the wet salt have no minerals. When in auto-tune mode and Sens on '10'........ bobbing the coil........ and the detector reports absolutely no audio variation......... no matter where the Grnd Bal is placed. Acts like the Grnd Bal knob is disconnected or out of the circuit. It's not. There is simply.... not enough minerals to Grnd Bal (compensate) for.

Thanks Tom