Went to a site I have pounded at least 4 times. Difference this time was a NEL snake coil, New Eneloop Pro batteries, and opening up the scree to having discrimination at FE 32-35. One Indian rang up a 11-36. I dug a zinc penny with a 3 inch nail above it. I think the SNAKE coil with a more open screen made the difference. I swear the New Batteries Eneloop Pro bateries make it hit harder and more sensitive. However is that possible? What is the shutoff voltage of the E-trac?