I've had my new DFX for a couple month's now and I am using the 9.5 " (950) coil. I'm starting to learn the readings and I am pleased with the accuracy. I am interested in getting a much smaller coil for trashy areas. Does anyone know if the readings produced by the smaller coil will stay consistent with the readings from the larger coil or am I going to have to learn all over again when I use the small coil? Thanks for your help.