I decided that with all my detectors and different coils I needed to plant a little test garden. So I searched my yard and found 3 places clear of iron and planted 3 dimes-6", 8" and 10". I was using my etrac with the 8" Sunray coil (only one I tried so far). I got a good signal on 6" but no signal on 8". To make a long story short-I was running deep on. When I changed to Deep off-a perfect signal at 8". Fast on or off made no difference. So........I thought deep on was suppose to enhance the deeper ones-but not at this particular location. Any thoughts or ideas?