Noise Cancel-12" vs contact w/ground?

[Monkeys Uncle]

The Minelab ETRAC manual instructs one to conduct Noise Cancel (ground balancing) by holding the coil steady, 12" above the ground. I've read others write to do it, letting the coil rest on the ground and heard another say "bump" the coil a few times on the ground during the procedure. Anyone know which is best and why? TIA, stay well and HH!!!

 

[sd51]

I'm going to say it doesn't matter but I prefer to leave the coil motionless on the ground until the E-TRAC completes the procedure. It's looking for EMI (electromagnetic interference) that could be radiating from either the air or the ground for that specific location, and selects the best channel to minimize the interference.

 

[IDXMonster]

“Bumping” or “pumping” the coil has nothing to do with “Noise Canceling” on a machine such as the etrac. This action is used on a machine which has the ability to “Ground Balance”, which negates the effects of mineralization. “Noise Canceling” is designed to negate the effect of EMI, or electrical interference, by way of shifting the frequency set slightly. I also prefer to let the coil rest on the ground to perform the “Noise Cancel” procedure, even though the manual tells you otherwise. The reasoning I put behind it is this....many times my EMI will actually be COMING FROM UNDERGROUND UTILITIES that are close by, so I want to have the coil in the “hunting position“, which is ON THE GROUND when looking for the quietest channel. I believe that Minelab assumed that MOST EMI would be coming from sources ABOVE ground, and that’s probably why they recommend to lift the coil 12” to perform the sequence.

 

[Monkeys Uncle]

My thanks to sd51 and IDXMonster. Was worried, no matter which technique I used...it would 'adversely' impact my search. THANKS again!! HH (but leave a little for us old timers)