interesting observation on E-Trac noise cancel

[randy]

So today I went back to the site I hit yesterday where I pulled a couple of silvers and a copper, and noticed the clad quarters were hitting at 12-46, when they almost always hit 11-47 for me around here. This was consistent, as I dug 11 clad quarters today. Why is this I wondered, different dirt at this site -- then I remembered that noise cancel assigned me channel 4, when it almost always assigns me channel 9 or 10. I don't think I've ever been assigned channel 4 before, so I manually set it to channel 10, and the clad quarters sounded like clad quarters again, and hit at 11-47.

Then I hit a deep silver, giving me a CO of 45 with an occasional bounce to 46. Before digging, and being naturally curious, I manually changed the channel from 10 to 4, and the same deep silver gave me a CO of 43 to 44, with an occasional bounce to 45. Again, channel 4 rang lower than channel 10 on the same conductive target.

What I think is happening is that each channel assigns different frequencies, and then the signal processing software has to take the analog frequency response and map it to a digital readout and a tone. But, the process isn't perfect (possibly due to rounding or some other software issues). I'm no engineer, but I do know of alot of E-Trac'er who want to know the best channel to operate on for deep silver, and this little experiment indicates that it may matter, at least for those who rely on the numbers.

(And obviously, we're gonna dig all deep high tones regardless of the numbers, and like many E-Trac'ers, I focus on the tone rather than the numbers anyway, but I just felt like sharing this little observation, FWIW).

Anyway, the deep silver turned out to be a '46 rosie. Also pulled a 41S merc, 37S buff, and a 6gr Tiffany sterling ring. Thanks for looking and HH.

[RobW]

That's good info and a great observation.

Those are some GREAT finds too! My wife would love for me to find a Tiffany ring for her lol

[Myownwings]

I found this interesting article regarding manually setting noise cancel channels.

http://www.minelab.com/usa/treasure-talk/e-trac-manual-versus-auto-features-for-expert-users

[randy]

I did some more experimenting with this today. I got a deep iffy signal, that I was pretty sure was a copper or silver. I was hunting on channel 6.

I went thru all the channels, and 2,6,9,10,11 gave me something I would dig. 1,7,8 were useless, no signal or maybe a threshold null at best, and 3,4,5 very iffy, to dig or not would have depended on my mood. Since I knew a target was there, it was tough to be objective on those.

2 and 6 suggested it may be a silver, 9,10,11 all were leaning towards wheatie, but there was a bit of bounce on all channels, and obviously it is hard to be sure on the deep ones. Anyway, turned out to be a wheatie on its side at 9.5 inches (measured, including 2 inches of grass).

I did try this test once before on a silver 8 inches deep, and all channels were fine. I know one target doesn't make a scientific test, but I lean superstitious on these matters (I've almost always used 9 or 10 anyway), so I'll be using one of 2,6,9,10,11 going forward.

FWIW, YMMV, and so forth. lol

[coinnut]

Very interesting :thinkingabout: :thinkingabout: I wonder if some of my falsing was because of a channel that was not really optimized. Sometime I run smooth and sometimes I get some falsing on the 12-01 thru 12-07 range when in TTF. I'm betting, from what I have read from you guys and that article, that I could probably silence that falsing just by picking the proper noise cancel channel. Food for thought and thanks guys for giving me more ammo when hunting with Del :clapping: :happydance01: thumbsup01

[Epi-hunter]

That is interesting :thinkingabout: Something to keep in mind.

HERE (http://www.americandetectorist.com/forum/index.php?topic=6106.msg72090#msg72090) is another thread started on the same topic.

[jkress]

Very, very interesting.
I don't use the E-Trac but have the Explorer SE. Over the course of the last two months, I started realizing the channel that my Garrett pinpointer
makes chatter is the one that seems to produce the best. My thought is that particular channel is monitoring/analyzing the most frequencies.

Sometimes when I am on my preferred channel, I won't noise cancel unless I absolutely need to when starting a new hunt.