I just thought i would put in my 2 cents worth about the masking issue, I have been finding a lot of coins that other detectors have missed due to being masked by what i call "hot rocks". They are similar to a lava rock and they read as metal in the ground but once dug up they don't. This week I read a hot rock with a -- on my readout but just as i would come off of the target i was getting a 84 87 83 88 . I was sure there was a coin in this hole, i dug down and popped out the hot rock around 4" and then i got a consistent coin reading more towards a quarter. The 1948 dime i dug was sitting on edge just to the side of the hot rock about 6 inches down.
Tnredneck
Tnredneck