Nulling

[mcdoogal]

Seems like its been a long time since I have heard a steady threshold done on my e trac. Many hunts in full null, or so it seems. If I snail pace it, I may get a threshold for a few seconds. I have been running manual sens at 28 and usually auto noise cancel. Has anyone else noticed this? Just wondering if my machine is OK. I am still making finds, so I guess it is not too bad.

[angellionel]

With that high a sensitivity, sites with mineralized soil or littered with bits and pieces of iron will cause the machine to null often. The threshold may not be discernible at all. However, the machine will still lock on to good targets, though it is advisable to go slow in order to hit on the deeper ones.

To discount any other possible cause, have you tried using auto-sensitivity at those same sites to see if you experience the same?

[randy]

Also try using two tone ferrous (TTF) if the site is littered with iron, It won't null as much, and you will hear the good targets among the iron. As Angel said, also try cranking down the sensitivity. If the problem is iron, you don't need a high sensitivity to pull keepers from that site that other machines have missed -- the E-Trac will see many of them (assuming you have Trash set to high). Think of high sensitivity like high beams in fog at sites like that.

Another possibility is power lines. Are there power lines at this site? I have one site where I can't get a threshold due to overhead power lines and a nearby cell tower. The E-Trac is great on EMI, but can't get a threshold at this site on any channel in manual, and auto cranks it down pretty low. Still have pulled silvers at the site in manual so I know the machine is fine. Hunting without a threshold can be disconcerting, but it doesn't necessarily mean there are problems with the machine.

If in doubt, try your machine at a different site. Also, as soon as you turn on the machine and place it to the ground, you should hear a threshold for the first 3 seconds or so before the ground balancing kicks in, no matter what. It always does this, no matter how trashy or mineralized the site is. If it is doing this, then I would bet the machine is fine.

[Epi-hunter]

Yes, make sure you have trash set to high. It is NOT the default.

I agree with the above. It sounds odd not to hear the threshold at all.

I would switch to auto sensitivity and see if you can figure out what is going on. If there is a huge difference then maybe you need to turn it down a few and something local may be going on.

I have nulling frequently but I hear the threshold tone throughout it and it does lock on the targets.

[jkress]

I don't use the E-Trac but I am assuming you can go to 'All Metal' mode on your machine. When you are experiencing constant nulling, switch to All Metal and see if there are actually targets under the coil that you have discriminated out. If you don't get any signals in All Metal from an area that you have no threshold... further investigation may be needed. But if you are picking up lots of iron signals in All Metal, then your machine is doing exactly what you told it to do.

[mcdoogal]

Thanks everyone. Sounds like my machine is OK. When I 1st turn it on, I do get the threshold for a short time. Most times in auto I get a threshold. The place(s) I have been hunting most lately have a reddish soil tint and thus may be high iron/mineral. Many times I swith to TTF and do fairly well with it but stilll many times with no threshold. I was just concerned that my machine may be sick. Thanks for all the help!