What makes the ground null out?

[Dig EM]

Running my e-trac yesterday and searched for a couple hours and found some old clad. Moved to a diffrent area and the threshold completly nulls out unless you lift the coil away from the ground. I have hunted this area before and have never noticed this. I was still getting targets but the backgroung hum was gone unless I lift the coil up. What gives? Could be from excessivly dry ground?

[Cheap Thrills]

The null happens when you go over metal that you have discriminated out like iron nails and such , ride the nulls out VERY slowly and from every angle and sometimes you can pick up a good target next to it . Also when you change to a different spot or you can tell the soil is different do a Noise Cancel :yes:

[DieHard]

On the e-trac when it is on you have a constant threshold sound. now if you got any discrimination and you pass your coil over what ever you have discriminated the threshold sound nulls or goes silent. Thats ok just slow your swing down and if there is a coin or other thing you don't have discriminated in or around while nulled out the e-trac still screams out loud. now to pin point while it is nulling you have to look at your screen at your cursor and pinpoint while watching your screen until the coin id shows up and the cursor is where it need to be for your target you want to dig.

Hope this help. Happy Hunting

[Dig EM]

I understand the threshold nulling out over disciminated item but whats going on it its null'ed out completly, i mean everywhere you sweep. The threshold never comes back unless you lift the coil a couple feet above the ground. Could that be mineralized ground aggravated by being extremely dry?? I have hunted this area before and have never had the threshold hum dissapear completly before.

[DieHard]

go to quick mask and see if it is iron. is it a big area that nulls out. might be highly mineralized.