Has anyone tried the 10x12 coils? And how did it work for you? I am getting great depth now but the silver coins in this one park are getting deeper. I think I have cleaned most of the shallow ones out at about 4-6 inches and am now in the 8-12 depth. The ground is rich dark soil an not too hard to dig. Mercury dimes hit solid in the zinc silver range but are getting fewer. I got a beautiful 1944 mercury at 8 to10 inch range that looks like someone dropped it yesterday.