Nulling

[dld]

I got a Explorer SE Pro a couple of weeks ago and am in the learners curve mode.
I hunted a sight that had a lot of little pieces of iron reading 31-31 to 31-28 every foot or so.
I tried hunting in the factory mode, even going real slow it was nulled out most of the time.
So I went to all metal but the screech of 31-31 to 31-28 was a little annoying.
I tried to eliminate the 31-31 to 31-28 but the almost full time null was back
any suggestions?

 

[MNCoinhunter]

Your Explorer is still doing it's job while it's nulling. I would just slow down and try to listen for anything good to come through. Some people can detect in All Metal and put up with the noise. I guess I would prefer to use the silence to pick up on any good sounds ... good luck !

 

[richard widder]

THE NULLING IS COMMON WHEN HUNTING WITH ANY TYPE OF IRON IN THE GROUND. YOU NEED TO SLOW TO A SNAILS PACE WHEN THAT IS HAPPENING. AND IF THERE IS A COIN IN THERE YOU WILL HERE IT. IF YOU GO TO FAST YOU WILL MISS IT. I HAVE FOUND SEVERAL COINS WITH IRON IN THE SAME HOLE AS THE COIN. YOUR NUMBERS WILL BE OFF.... BUT THE SQUEEK TELLS DIFFERENT. HH

 

[TwoRivers]

I use a small coil in heavily iron infested ground (nails etc..)...With the smaller coil you'll be able to pick out even more coins..Stay with it, the SE is a great detector and you'll love it once you learn it............HH..............John in Va

 

[sgoss66]

Two things --

Some desirable targets are simply "masked" by iron, and thus un-detectable. So, the simple fact is that you will not hear a substantial number of the "good" targets in the ground at an iron-filled site. Whether they are detectable or not depends upon the exact orientation of the iron relative to the good target. If the iron is rendering a particular target un-detectable, then obviously your machine will not see that target. In other words, your "null" will not be "broken," in that case, and you will miss that target. However, you are not missing targets DUE to the nulling; the null is just a consequence of the presence of the iron. This "missing of targets" is just the way it is with iron present -- you always have the potential for iron to "mask" a good target. Going SLOW, as others have mentioned, and switching to a smaller coil, are the best things you can do to combat an iron-laden site. You WILL still miss targets though...many of them. NASA Tom Dankowski estimates that 90% (I think that's the right percent) of targets are missed due to masking. If you are in a null, and you hear a good target "squeak through," then by definition that good target was not totally masked, but only partially masked. A fully-masked target is, by definition, un-detectable. So again -- yes, you DO miss good targets while your machine is in a null, but other, non-threshold-based machines ALSO miss masked targets. The null is not the CAUSE of the missed target, the null is simply telling you that iron is under your coil (and, likewise, that the POTENTIAL for that iron to "mask" targets is also occurring beneath your coil.)

I also see where you said you tried all-metal mode, but the "screech" of the iron targets was too much for you. If you ever want to try that again, you may want to try switching to "ferrous" sounds, instead of the default "conductive" sounds. When in all metal, and running ferrous sounds, the iron -- instead of being a high screech (due to the high conductive number) -- will instead be a low grunt. In ferrous sounds, the higher the FE number, the lower the tone, and the lower the FE number, the higher the tone. So, a 31-28 target would be the very lowest tone, while a 00-28 target would be the highest tone.

Just some thoughts.

Steve

 

[dld]

Thanks guys

 

[Chris(SoCenWI)]

Hey Steve,

Very good explanation. Would also mention that whether a target is TOTALLY masked also involves the angle of attack of the COIL in relation to the orientation of the TRASH item(s) in relation to the GOOD target. Especially with DD coils. There are times where a only a few of degrees of difference can result in a null(low tone in open screen) or something more interesting sounding.

I'm an open screen guy and believe like many others that the recovery time between a low tone to high tone vs coming out of a null is a bit faster; thus allowing better finds in heavy trash. Whether true or not???

Chris

 

[sgoss66]

Chris --

Totally agree, with respect to the angle of attack of the coil, w.r.t. finding targets amongst iron.

Also, I wonder the very same thing as you -- is the recovery time from a low tone to a high tone (when using an open screen) a bit faster than recovery "out of a null" (when in disc mode)? I do NOT have the answer to that, but my uneducated guess would be yes, the recovery between targets when NOT using any discrimination (open screen) would be maybe a tad faster...but I could be totally wrong.

Steve