I was doing some testing with my Gold Bug Pro using the 5 inch DD coil. When I ran the coil over a clad dime I got a 82-83 ID reading. I then ran the coil over a beer bottle pry cap and got the same reading. I started experimenting around to see if there was an easy way to distinguish between the two. Well, I think found a way. Once you're centered over the target getting the strongest reading, jerk the coil straight up about 3 or 4 inches. The dime will keep its ID number with repeated jerks, but the pry cap ID numbers will vary from the 40's, 50's, 60's and 70's with each jerk.
tabman
tabman