I start out with sensitivity at about 3 o'clock and adjust up/down as needed....lower to avoid interference, higher for depth where there is no interference. I set the switch on the right to "discriminate" and the discriminator knob to about 11 o'clock. When I find a good sounding target, I then flip to "tone" and if it still sounds solid, I will go back to "discriminate" and slowly increase discrimination clockwise until the signal starts cracking up, or stops. Based upon where it stops I can get a good feel for whether it is a coin & what kind. Or, I can flip to "all metal" and dig all. Do a search on "settings" in the Bounty Hunter forum...there are a lot of Tracker IV comments. As for the ground being frozen, there is always a hammer and chisel...