I did a coil test some time ago using a Tdi Pro OZ, quite a variety of coils involved. Just a bit of information not wanting it to go to waste. The test area was located in the middle of the Golden Triangle in Victoria, Australia. Looking at the images the test site is located on a area that produced large nuggets. Heavily mineralized to give the depth tests some authenticity. Targets were varied as were the coils tested. The Tdi Pro was ground balanced, gain was at 5, conductivity was in A