I just got a coiltek 3 khz digger coil and took it out for about an hour. I dug about 25 pulltabs and not a single coin. I keep reading that everyone loves this coil. every pulltab I dug rang up 38-40-42. you would think at 3 khz this coil would not hit these very hard. if anyone has any tips or info on this coil I'd appreciate it.