Some good explanations on ferrites and GB here

It seems this "patch" has been around for a couple of months. I wish I'd known about it earlier.

http://golddetecting.forumotion.com/t21742-new-ground-balance-with-ferrite-for-gpz7000

I'll try it when I get my 7000 back from the cobblers.

WA is notorious for iron based deposits. There is very little area here that doesn't have iron of some type in the soil. In fact most of my good gold always came from the dark, almost black pisolite dirt. Quartz areas are quiet but iron can be a handful. WA needs iron/quartz to generate most of it's gold. It was often said by past ML testers that WA is the worst ground in the world for a metal detector. I think Bruce Candy may have said it as well, from memory.

But I reckon you may need to carry this ferrite with you & rebalance with or without it as the ground changes under your coil as the day progresses. It may even get rid of 90% of the "hee haws" as I don't believe for one minute that there is THAT much underlying salt in WA; i.e enough to send the machine "hee hawing" 40% of the time. I reckon most of the imbalance is caused by fine iron sediment, the stuff that makes WA look "red allover".

I really hope this is a fix.

Les the 7 up here in the pilbara is noisy as hell on the iron covered ground but the signals still come through once you get used to the constant groaning of a 10000 $ plus machine, t he 23 handles the same ground without issue but lacks out right depth on smaller bits, bigger bits on the 23 no worries surprisingly at good depth without the noise.

NOW - and I can't stress this enough Minelab! Now,,,,,,,,,,,,,,,that reply is very reassuring. It's a question that a lot of experienced detector operators have asked.

It goes like this, "If my detector starts "hee haw" then the GB is way out and I won't hear a target". I and a lot of others accept this as a "given". It's what we were raised on.

This reply gives us reassurance that should the 7000 start misbehaving, the target signal will still "punch through".

Just a pity that ML didn't see fit to re-educate us "long timers"?

Good post KTS