I've had my Etrac a month or so, and one of the things I remember who has had years on his telling me is that he's never found anything good with a ferrous reading of 01. Recently, though, I've gone back and looked at Andy's book and I see that he has some coins listed as giving a 01 reading. I know there's all kinds of things that can alter what shows up (angle, depth, corrosion, wear, etc) but I'm curious how often a 01 ferrous reading is actually something I should be digging if the conductivity numbers look good...