R2 positive offset GB

I've an old worn half penny buried at 9-10 inch in my garden, upto now the R2 could only get it on deep mode but i tried in 2 tone today with a + gb and it got it good, anyone done any testing on this to give the best average amount of + GB???

ghound Wrote:
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> I've an old worn half penny buried at 9-10 inch in
> my garden, upto now the R2 could only get it on
> deep mode but i tried in 2 tone today with a + gb
> and it got it good, anyone done any testing on
> this to give the best average amount of + GB???

how much + did you go?

was just going to ask the same question.

My ground balances out at 75, with 3-4 bar on the mineral scale, i started at factory 90gb and the coin came through clean, i need to spend a little more time experimenting to find the sweet spot!

Sounds good, I'll do some experimenting on it when the weather warms back up.

Usually higher ground balances cause the loss of sensitivity to coins like dimes quarters halves and dollars..too high and you can loose Dollars..

But higher G.B. makes it more sensitive to low conductors..

Keith

“I don't care that they stole my idea . . I care that they don't have any of their own”
-Nikola Tesla

About an hour or so I'll post a video loading to the Tube right now. Small coil, coin garden, 10" dime, 11" quarter, 8" penny, 7.5 to 8" nickel with nails above it. No GB manipulation needed. The dime gives some trouble, all the rest it blows out of the water........................

Jack, can you post the gb and the bars on the mineral scale for the test, im waiting for the nel attack coil to arrive and i will run a few tests with it, cheers Robert

If I was changing ground balance, it would be negative balance for copper & silver.

This thread has me puzzled, too. Setting the GB value to a 'neutral ground' 90 value would be the kind of thing that would lose you a couple of inches depth, I would think.

Pimento Wrote:
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> This thread has me puzzled, too. Setting the GB
> value to a 'neutral ground' 90 value would be the
> kind of thing that would lose you a couple of
> inches depth, I would think.

I believe 90 GB phase would be in areas of black sand. I have a fresh water beach that on occasion has streaks of the stuff that balance at 85-86 when hitting those.
Otherwise most areas around here GB at 79-81 on the Racer and Teknetics machines.

Tom

Yes, black sand is one way to get a '90' / ferrite GB - basically some iron, and relatively speaking, little mineral content, so the iron dominates, and the ground phase angle is close to zero lag. So ground with normal mineral level, and a LOT of iron, will also read '90'

Regardless, setting GB a long way from 'ideal' is not going to help detection, surely?