GT nulling out

[EdUK]

I have a little bit of land search on right now, the problem is that my GT is constantly nulling out on it( BBS 1000 coil). I have tried turning down the sensitivity and sweeping slower- is there anything else that I can do apart from buying a smaller coil please ?

 

[Art (NWOH)]

How far have you turned down the sensitivity? To what position? Have you tried auto?
What kind of places are you using it? High iron trash or high iron content dirt?

HH

 

[Neil]

make sure your disc and notch are set at their lowest level. how far have you turned down your sens? you will still get excellent depth with it set at 3 oclock or even try minimum sens and see how it does.

if you dont mind digging, try the all metal mode(pinpoint) and try digging targets by their size, coins I would guess is what your after? on the GT in the all metal tracking mode the tone is much broader similiar to the disc mode, thats why I mentioned the pinpoint mode to help size targets.

HH
Neil

 

[EdUK]

I have tried the sens all the way down and in auto but nothing seems to make much of a difference.
This particular piece of land is pasture and I suspect it has a long history of being farm land. I have found quite a few iron objects (horseshoes tractor parts etc) but I don't honestly know if it the dirt is highly mineralised - how do you tell ? I will have to go back and have a go at using all metal. I could certainly try to id by size too.thanks for your replies.

 

[Art (NWOH)]

If you wave a handful of dirt ( without any objects in it) over the coil and get much change in threshold, then the dirt has a lot of mineral. No change in threshold indicates decent dirt.

HH

 

[EdUK]

I'll give that a go, thanks.

 

[Art (NWOH)]

You might try some air tests to see how far it can pick up a coin without any dirt being involved.
The reason I say this is that one time I had a Detech coil go bad. Would work for a few minutes, then start making long nulls and would chatter . Would not pick up much of anything while it was acting up.
HH

 

[Cal_Cobra]

I had that problem with the stock 10" coil, and ended up getting the 8" Coinsearch coil for $50 on ebay. It works well, and now I can crank up the sens.

 

[EdUK]

I will keep an eye open for an 8" coil but I think it will cost me big over here (England). Thanks to you all for your help.

 

[Cal_Cobra]

I will keep an eye open for an 8" coil but I think it will cost me big over here (England). Thanks to you all for your help.

I picked mine up from a chap in Australia via ebay, and $50 included shipping. Most people agree that the 8" Coinsearch can do as well, or better then the 10" stock coils, and does a far better job at target separation and wading through trash. Worth a shot if you spot one on ebay.

HH,
Brian

 

[Rick(ND)]

n/t

 

[samol100]

8" coil on ebay uk , buy now

 

[EdUK]

Nice one - I'll check if it's still on there and empty the piggy bank

 

[bottlebum]

Ed, does the machine stop nulling if you stop swinging the coil? The reason I as is because I have a site that I know is loaded with old iron and old nails and when I try to search it the machine is constantly in the null while swinging the detector but the threshold will return as soon as I stop swinging the detector. It happens whether i'm using the 1000 or the 800 Tornado coil. I have noticed that even though it is almost constantly in the null, it will still sound off on a good target.

 

[EdUK]

Not sure to be honest. I will try that on my next days off. I am now starting to wonder if I was turning the sens control the correct way when I thought I was turning it down. I probably was doing it right - I find that doubt creeps in with time.

 

[cap10joe2000]

If you have a coil cover on your coil make sure no sand or dirt has worked its way in between the cover and coil. This drives my GT crazy.

 

[EdUK]

I will have a look at that too, thanks.