Here's an interesting test that illustrates masking:nerd:

[tabdog]

This test was introduced to me by a member on the Tesoro forum.

Take a 3" or 4" tall card board or past board box. Put a quarter in the bottom of the box or under it. You should be able to get a signal.

Put 4 or 5 regular staples on top of the box and over the quarter. Now scan over the box.

Any one care to comment?

I would be interested in anyone's reaction,

 

[metaltectinria]

Well I tried it. I have a Classic III with mr bills mods. I had no trouble getting a perfect signal on the quarter with or without the staples. I had the same signal throughout the disc range. I put down about 15 staples and still had no issues. I would be interested in how some "high end" machines with several filters do in this test.

 

[tabdog]

Thanks for your reply. I can't get a clear response with either of my detectors. I would like to know which ones can get a good response, or partial response. Your'es is the first one that can get a strong signal that I know of.

Cheers,

 

[Pap]

odd because one of the detectors I tested on this was a classic lll but without the mods. I don't think having the modifacations alter the discrimination ability in any way do they?

 

[metaltectinria]

The mods add a boost circuit to the sensetivity in discrimination mode. I guess Ill just have to make a video of this and post it on youtube or something.

 

[UK Brian]

Ground balance, threshold and boost mods all help the machine achieve the best performance in a variety of soils but your quite right there's no improvement in the discrimination abilities, just the depth obtained in that setting.

 

[tabdog]

If you have quality headphones. And if you offset the quarter by different amounts you may hear responses that are similar to some of those received in the field. It's like a broken signal with part of a good response but starts or ends with rejection or a iron response and alternates as I swing back and forth. I have been studying this problem at home and in the field for a couple of months. I have learned from this that I can catch some of those hidden signals.

I usually just dig if I have any question, but I discovered something odd. If there is a good target slightly offset and under trash, like a coin under a pull tab close to the surface, I can angle the coil on the side of the good part of the response and go to and fro from the target until I can get under the trash and get a good response. This may not be all that useful sense I would dig any way, but it is a useful learning experience. It will be useful in hard pack ground.

Cheers,

 

[beatty_dt]

Looks like this is something I can try indoors.

David at Edmonton