Coinseeker 78
New member
I have been experimenting with threshold setting on the F70 and have found some interesting information. It seems the default setting is -3 and it is mentioned that default threshold used to be 0. Why has Fisher changed the threshold setting from 0 to minus three? I believe it may have something to do with quieting the machine down. Unfortunately I have found you lose up to 3 inches of depth with the threshold set at -3. With the threshold at 0 or higher you do not have this loss of depth. I am finding with the 5 inch DD coil set at 60 sensitivity 0 disc and SL setting where possible I can get up to 11 or twelve inches in air testing with coins. This is fantastic depth for a 5 inch coil. I have dug several coins at 8 inches or 9 inches with these settings. I set the HZ settings for the lowest chatter or no chatter around moderate to low EMI. I found a beaver tail tab without the ring attached at 8 inches today. I have also found with these settings and the 8X11DD coil I can get 13 to 15 inches with air tests on American coins. In short the depth capability of the f 70 is outstanding and will hold its own with about any detector out there.Let me know what you more experienced Fisher detectorist think about these settings. I am hunting mostly Indiana soil which is mild to moderate mineralization.