Discrimation and Depth

[Canewrap]

I know that one of the ways people identify targets is to thumb the discrimination knob until they lose the target. What I want to know is if anybody has performed an in-air test where they also changed the discrimination level to see how much it changed the potential depth? I've proven to myself in the field that discrimination does rob a machine of depth. Accepting that premise we really need to know how much change there is in depth, because if the target you are identifying this way is on the edge of your depth, you will lose it as soon as you start thumbing the discriminator and you'll assume it was junk.

 

[Pap]

Now you've done it!!
You are correct in your analysis. That is why if the signal is weak the best discrimination is your digging tool and holding the target in your hand. ALL detectors lose some depth when the discrimination is increased; some more that others, some models of the same manufacturer more than others. Basically speaking, that is why all metal will have more depth than discrimination. You can bring up the subject of 180 ED & 120 ED and it has almost no bearing on what you have just stated. This is the very reason that many users of TID detectors will open their discrimination quite a bit and dig all targets responding with an audio response that, along with certain other responses such as the depth reading and size, might indicate a good target.
So yes, if the audio response was faint and you "thumb" the discrimination knob the target could drop out because of the increased effect of the discrimination's reduction of depth rather than the target being rejected by the discrimination setting itself.
Pap

 

[tabdog]

I have done air test with discremination to try and get a handle on it.

What I descovered is that air has no resistance to the MD's signal.

Natural ground affects the response so much that there is little simalarity

between air test and natural ground. A test garden may be a better way to

conduct the test for discremination and depth. But you will have to burry a

set of targets just for the test unless you already have the test targets

burried at the correct depths. That's a pain in the yazoo. The best way is

to test this out while having fun metal detecting.

HH,

 

[JHM]

Does you detector have vco pinpoint? If it does, thumb the disc. If you lose the target before the nickel setting, check in vco pinpoint. Low tone= dig, High tone= keep walking.

 

[Canewrap]

I've never heard this before, but it makes sense. Seems like people fail to mention doing this in combination with the thumbing disc. technique. I'll have to give it a try. I can't say I've ever paid attention to the difference in the pinpoint signal, but seems it could be real useful.

 

[JHM]

I know it works with the vaquero, cibola, & tejon. If you haven't already, bury some coins in the back yard. It will hep alot.

 

[markg]

Ok Pap, your exactly right.
Using my Tejon, I've noticed the same type thing, that's why if I get a good repeatable beep with the disc set to foil I dig.
I try to listen for the faint beeps because they're usually the deeper and possibly the oldest. Still learning and have a way to go, but after years of hunting I'm just now starting to understand the old saying, "If it beeps, dig it".
Thanks for the post, it helps to have reassurance every now and then.



[quote Pap]Now you've done it!!
You are correct in your analysis. That is why if the signal is weak the best discrimination is your digging tool and holding the target in your hand. ALL detectors lose some depth when the discrimination is increased; some more that others, some models of the same manufacturer more than others. Basically speaking, that is why all metal will have more depth than discrimination. You can bring up the subject of 180 ED & 120 ED and it has almost no bearing on what you have just stated. This is the very reason that many users of TID detectors will open their discrimination quite a bit and dig all targets responding with an audio response that, along with certain other responses such as the depth reading and size, might indicate a good target.
So yes, if the audio response was faint and you "thumb" the discrimination knob the target could drop out because of the increased effect of the discrimination's reduction of depth rather than the target being rejected by the discrimination setting itself.
Pap[/quote]

 

[markg]

Another good post

 

[tabdog]

reject a lot of small iron without loosing any depth.

I learned pretty quick to not worry as much about

the targets my Silver didn't like. It usaully goes after

the likely targets, sometimes with supprising depth.


All that depends on the type of hunting I'm doing.

That's why I have more than one.

HH,