this is one book that will really open up your eyes (and ears) to detecting! Larry(IN) suggested I read a book entitled "Taking a Closer Look at Metal Detector Discrimination" by Robert Brockett. I bought one, read it, re-read it and read it again. This book is excellent! After 34 years of detecting, it makes me wonder how much stuff I have passed over because I wasn't fully aware of what the detector was telling me? It pertains primarily to the Whites analog detector. But the principles discussed apply to all of them! If you haven't read this book, I certainly recommend it! HH Randy