I'm a first time ETrac user and new to Minelab as well. Just finished your book on ET, which I thought was well written and very informative. The section on the FE 12 line and CO numbers for various coins was extremely helpful to me. My question concerns the tendency for deep coins to fall off the FE 12 line as their depth increases. At what depth does this become noticeable, and could you give me any examples of deep coins you have located whose FE number was greater than 12 and the associated depth? I've been digging anything with a coin like CO indication and FE values of 26 or less, but was just trying to get a clearer picture in my mind of how the deep coins typically indicate when they do fall off the FE 12 line. Thanks and Happy hunting, Brian.