Fisher F75 GB - Problem/Phenomenon

[GeorgF]

Hello.

If i do the GB with my F75 i have following effect.:

After doing the GB there is always shown the value of the soil mineralization on the displayed -For example 50.
Out of interest i changed the value manually to 90 an saved this setting. according to this i did the GB again and normally there have to be the 50 as before on the display.
But the value did

 

[Scully]

n/t

 

[GeorgF]

Hi Scully.

I do the GB accurately as in the manual from page 14-16 described.

Regards
George

 

[John(Tx)]

on my F70, when I have problems, I do the GB in All Metal and it makes a world of difference. Hope this helps. John

 

[John(Tx)]

BTW Georg, my F70 always defaults back to 90 GB whenever I turn if off and then back on, doesn't save the last setting. The F70 does not have manual GB like the F75, maybe that's the difference. John

 

[reidman]

If the minerals present are lower then 40 you have to do a manual GB it explains this in the manual, didn't you read it" I am guessing you are in a lower minerals area so the detector doesn't gb it says can't GB in the display. Then you follow the manual procedure to manual GB. In most cases you can just set it at 40 and go as the minerals are so low there isn't much need in balancing them out.

 

[John(Tx)]

on the Texas Gulf coast, very, very low mineralization, it's a curse! ha ha

 

[GeorgF]

At first thank`s to everyone for the assistance.

What i find out and what works for me is.:

I turn on the F75 and before i do the GB in the fast grab mode i turn back the GB Value in the manually mode up to 0. Than i do the GB in the fast grab (not to slow) and it works for me - as you see.

enclosed picture of a (unfortunately) half cannon ball.
on the second picture the same in the middle, in cleaned condition.