Equinox noise cancel in the air at waist height or on the ground question

[vferrari]

Just having a bit o fun. Lol.

 

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[sgoss66]

Just to throw in my two cents...

Noise cancelling is of course an attempt to mitigate the effects of EMI, with respect to target signals.

Ground balancing is of course an attempt to mitigate the effects of ground minerals, with respect to target signals.

The source of EMI is NOT the ground (unless you are dealing with buried electric lines, underground dog fences, etc.) So -- noise cancelling "near the ground" is not "more beneficial," in any way -- due to the fact that, again, the ground is not the source of EMI most of the time. Conversely, since sources of EMI normally reside above ground, one can arguably "sample," or "receive" more of the EMI that is present by holding the coil above the ground.

In fact -- let's say for the sake of argument that the source of EMI in a given spot is a lone building, which has a wireless router turned on, and broadcasting WiFi signal. In that case, assuming that this lone building's WiFi signal is the main source of EMI in that area, aiming your coil directly AT the lone building, so as to allow the machine to "most effectively sample" the electromagnetic transmission from the router, might make sense -- and some argue that it IS a good way to allow a machine to most effectively mitigate EMI.

However, since we often don't know the location of the source of the EMI, and since more often than not, there are MULTIPLE sources, then it makes sense that just "holding your coil above the ground," perhaps at waist height, would be a reasonably good way to run a noise cancel -- and, as vferrari noted, is consistent with the Equinox instruction manual.

But -- I think it is important to note once more, for those who may be a bit uncertain, that noise cancel has NOTHING to do with mitigating "ground noise." The "noise" a detector is hearing from the ground, is of course indicative of GROUND MINERALIZATION, and mineralization being reported by the machine is in NO WAY "mitigated," or "dealt with," via "noise cancel." Ground mineral is "mitigated," of course, via ground balancing (or other methods of "handling" mineralization, as is the case within Minelab's FBS algorithms).

Finally, I would like to note that we do sometimes underestimate the EFFECTS of EMI. "NASA-Tom" Dankowski has an immense amount of knowledge in this area, and he is a HUGE proponent of educating detectorists on just how much of an effect EMI can have, on a detector's ability to find targets on a given day, at a given site. There was a very interesting, recent discussion over at NASA-Tom's forum, on this topic. I won't repeat all of it here, as many would find it tedious and long-winded. However, what I will say is that he recently documented a case where he performed air testing of a dime, at a given site, on different days, and using different noise cancel channels. Some channels were silent, some were noisy, but even some of the channels that were silent were experiencing "silent" EMI -- to the degree that SOME of the "silent" channels produced good depth results on the dime, and some were extremely crippled, in terms of detecting that dime at depth.

I will post a short "snippet" of one of his posts describing this testing, in quotes, below. I find this FASCINATING...

"I tested EQX in Prospecting Mode-2 ...at one of my remote test-gardens ...….. with the following air-test results on a clad dime:

Dec. 03 = 12" in Noise Cancel channel -6
Dec. 04 = 10" in Noise Cancel channel -6
Dec. 07 = 13" in Noise Cancel channel -6

No other settings were changed. All parameters were exactly the same. On Dec. 03 and Dec. 07...... absolutely zero audible EMI. On Dec. 04..... I could hear a very slight amount of EMI chatter. Certainly not enough for me to be concerned about. (((Or should I be!!))). Can you see were there's 'significance' in an air-test? Can you see were there's 'significance' in carrying a spare dime.... for a 15 second test?

At this same exact site...…. on Dec 09...…. I encountered the following resultant:

Noise Cancel channel '0' = 10"
Noise Cancel channel '7' = 13"

Soooooooooo………..by virtue of carrying a dime with me in the field...…. and taking 20 seconds to test the best (top two EMI-free) Noise Cancel channels.... in an air-test; subsequently to witness/experience a 10" noise-free channel...… and a 13" noise-free channel...……. do you think I should then proceed to hunt with the 10" channel?
Again...… can you see the importance of carrying a spare dime with you...in the field?"

(the above quote attributed to NASA-Tom Dankowski, Dec. 2018).

Again, I find those results FASCINATING, and they do show that EMI can have DRASTIC effects on detector performance -- from site to site, and from day to day at the same site, and OF COURSE from amongst different noise-cancel channels.

Just some food for thought...

Steve​

​

 

[Terry Soloman]

My wife's idea of "Noise Canceling."

 

[sgoss66]

Terry --

LOL! I can relate to that! My wife would agree!
In fact, there are some here, that might want to noise-cancel me, as in your picture, after that last long-winded post I made! LOL!!

Steve

 

[relicmeister]

Unless I’m near power lines, homes and the like, I don’t always bother to noise cancel at all, and since my ground is pretty neutral, I just leave the GB at the default zero.If I’m not running quiet at 20 plus sensitivity, then i noise cancel, but hardly ever ground balance.

 

[vferrari]

Just to throw in my two cents...

Noise cancelling is of course an attempt to mitigate the effects of EMI, with respect to target signals.

Ground balancing is of course an attempt to mitigate the effects of ground minerals, with respect to target signals.

The source of EMI is NOT the ground (unless you are dealing with buried electric lines, underground dog fences, etc.) So -- noise cancelling "near the ground" is not "more beneficial, in any way -- due to the fact that, again, the ground is not the source of EMI most of the time. Conversely, since sources of EMI normally reside above ground, one can arguably "sample," or "receive" more of the EMI that is present by holding the coil above the ground.

In fact -- let's say for the sake of argument that the source of EMI in a given spot is a lone building, which has a wireless router turned on, and broadcasting WiFi signal. In that case, assuming that this lone building's WiFi signal is the main source of EMI in that area, aiming your coil directly AT the lone building, so as to allow the machine to "most effectively sample" the EMI being transmitted, might make sense -- and some argue that it IS a good way to allow a machine to most effectively mitigate EMI.

However, since we often don't know the location of the source of the EMI, and since more often than not, there are MULTIPLE sources, then it makes sense that just "holding your coil above the ground," perhaps at waist height, would be a reasonably good way to run a noise cancel -- and, as vferrari noted, is consistent with the Equinox instruction manual.

But -- I think it is important to note once more, for those who may be a bit uncertain, that noise cancel has NOTHING to do with mitigating "ground noise." The "noise" a detector is hearing from the ground, is of course indicative of GROUND MINERALIZATION, and mineralization being reported by the machine is in NO WAY "mitigated," or "dealt with," via "noise cancel." Ground mineral can ONLY be "mitigated," of course, via ground balancing.

Finally, I would like to note that we do sometimes underestimate the EFFECTS of EMI. "NASA-Tom" Dankowski has an immense amount of knowledge in this area, and he is a HUGE proponent of educating detectorists on just how much of an effect EMI can have, on a detector's ability to find targets on a given day, at a given site. There was a very interesting, recent discussion over at NASA-Tom's forum, on this topic. I won't repeat all of it here, as many would find it tedious and long-winded. However, what I will say is that he recently documented a case where he performed air testing of a dime, at a given site, on different days, and using different noise cancel channels. Some channels were silent, some were noisy, but even some of the channels that were silent were experiencing "silent" EMI -- to the degree that SOME of the "silent" channels produced good depth results on the dime, and some were extremely crippled, in terms of detecting that dime at depth.

I will post a short "snippet" of one of his posts describing this testing, in quotes, below. I find this FASCINATING...

"I tested EQX in Prospecting Mode-2 ...at one of my remote test-gardens ...….. with the following air-test results on a clad dime:

Dec. 03 = 12" in Noise Cancel channel -6
Dec. 04 = 10" in Noise Cancel channel -6
Dec. 07 = 13" in Noise Cancel channel -6

No other settings were changed. All parameters were exactly the same. On Dec. 03 and Dec. 07...... absolutely zero audible EMI. On Dec. 04..... I could hear a very slight amount of EMI chatter. Certainly not enough for me to be concerned about. (((Or should I be!!))). Can you see were there's 'significance' in an air-test? Can you see were there's 'significance' in carrying a spare dime.... for a 15 second test?

At this same exact site...…. on Dec 09...…. I encountered the following resultant:

Noise Cancel channel '0' = 10"
Noise Cancel channel '7' = 13"

Soooooooooo………..by virtue of carrying a dime with me in the field...…. and taking 20 seconds to test the best (top two EMI-free) Noise Cancel channels.... in an air-test; subsequently to witness/experience a 10" noise-free channel...… and a 13" noise-free channel...……. do you think I should then proceed to hunt with the 10" channel?
Again...… can you see the importance of carrying a spare dime with you...in the field?"

(the above quote attributed to NASA-Tom Dankowski, Dec. 2018).

Again, I find those results FASCINATING, and they do show that EMI can have DRASTIC effects on detector performance -- from site to site, and from day to day at the same site, and OF COURSE from amongst different noise-cancel channels.

Just some food for thought...

Steve​

​

Applaud Dankowski's approach, but it's still more of a dice roll than an actual scientific method because there are a myriad of other variables not under Tom's control that can be affecting his dime air test results including the fact that things could be very different with a target of different composition. I could go on and on poking holes but will refrain from doing so because although I do not place much stock in the dime test as really generating a true advantage, I also similarly think it does no real harm.

Regarding holding the coil near the ground, obviously while there are likely no ground based sources of EMI without buried cables, the ground does have a potentially shielding affect on the received site EMI signals Equinox is attempting to monitor on each of the channels so you really want your antenna (the coil) away from the ground to mitigate this shielding effect.

Finally, for 600 users, Auto noise cancel is their only choice, so the dime method is not an option. Should they panic? Um, no. Absolutely not.

Again, Tom's observations are interesting to me and others from a purely academic standpoint so thanks for sharing them, Steve. However, I think that implying that the right thing to to do is to necessarily act on these observations (as Tom does "Again...… can you see the importance of carrying a spare dime with you...in the field?") only introduces unnecessary overthinking and anxiety over something for which there is little control and frankly probably minimal impact IMO. Others may find the dime test to be useful in the field, which is great. I just dont think people should be overly concerned about it.

 

[sgoss66]

vferrari --

I get your points, and I agree that this is not something to overly obsess over, for most folks. My brain resonates with a "scientific approach" to things, and so I like to think about things such as what NASA-Tom points to here. Other folks, though -- probably MOST other folks -- couldn't care less. They are out detecting to "have fun" and "relax," and so obsessing over small details such as "which noise cancel channel gives the very best depth results" on a given target would probably do nothing but "take the fun and relaxation" out of the hobby. For those folks, I get it -- and I'd agree, no reason to obsess or worry about things. BUT -- for the small subset of folks with a peculiar "bent" toward the technical/scientific aspects of life, and function in that realm much of the time, NASA-Tom's thoughts/approach may be of more interest.

I realize, when I post these things, that most people probably roll their eyes and mutter "who cares" under their breath! But if a few people glean anything helpful, then I guess that's what I hope for.

I do think what he did, in his experimenting, WAS pretty valid, scientifically, as he did try to "hold all other variables constant," and change only ONE at a time (only the noise-cancel channel was treated as the variable, on Dec. 9, and only the "day" was varied, Dec. 4-7).

Anyway, it was interesting, to me...

Thanks!

Steve

 

[Terry Soloman]

I appreciate and value you Steve. I just hate Norman, Oklahoma, because it brings back memories of Lawton, and Ft. Sill.

 

[vferrari]

Steve - like I said in my post, I personally found it interesting and I am also glad you posted it, it was more a comment on NASA Tom's conclusions than opposition to to the information being put out there.

Regarding his method, despite his meticulous setup, there are still a lot of variables he couldn't control. For example, since EMI is frequency dependent, he may have found a channel that gave him maximum depth on the dime but that same channel may have given him less depth on a gold ring, who knows. Far from conclusive evidence other than he probably has the right channel dialed in if all he is going for is dimes and perhaps other high conductors. I just thought it amusing he thought bringing a dime into the field enabled him to conclusively dial in the best channel. I think I'll let my ears do the work, but acknowledge that silent EMI is real and his approach might be a credible way to attack it.

I also admit I am being somewhat the contrarian about this, but am slowly coming to the realization that all the variables involved in detecting makes me really skeptical af just about any detector air or soil depth test as being conclusive.

Again, thanks for sharing the info, Steve.

 

[sgoss66]

I appreciate and value you Steve. I just hate Norman, Oklahoma, because it brings back memories of Lawton, and Ft. Sill.

Thanks, Terry!

And I understand, about Lawton and Ft. Sill!

Steve

 

[sgoss66]

Steve - like I said in my post, I personally found it interesting and I am also glad you posted it, it was more a comment on NASA Tom's conclusions than opposition to to the information being put out there.

Regarding his method, despite his meticulous setup, there are still a lot of variables he couldn't control. For example, since EMI is frequency dependent, he may have found a channel that gave him maximum depth on the dime but that same channel may have given him less depth on a gold ring, who knows. Far from conclusive evidence other than he probably has the right channel dialed in if all he is going for is dimes and perhaps other high conductors. I just thought it amusing he thought bringing a dime into the field enabled him to conclusively dial in the best channel. I think I'll let my ears do the work, but acknowledge that silent EMI is real and his approach might be a credible way to attack it.

I also admit I am being somewhat the contrarian about this, but am slowly coming to the realization that all the variables involved in detecting makes me really skeptical af just about any detector air or soil depth test as being conclusive.

Again, thanks for sharing the info, Steve.

vferrari -- I knew you weren't picking on my post specifically, so much as just having skepticism about the whole idea. I get that!

And yes, without him testing that noise-cancel channel on OTHER conductors, he can't probably can't make any solid conclusions about any target, other than a dime, or similar coin. I will note that what he mentioned elsewhere, but not in the part I quoted, was that he WAS coin hunting...

Anyway, I totally agree...all of the variables involved in detecting make it difficult to draw any solid conclusions from depth tests of ANY kind. I think there are things you CAN test, and conclusions you CAN draw from those tests, BUT, you do have to be quite careful of the conclusions you draw. For instance, if I test two coils, on the same machine, same settings, side-by-side, I can draw much firmer conclusions from that type of test than I can when testing on different days, or testing the two coils at different sites, or ESPECIALLY in comparing one person's "six-inch coil results" to what I can expect from MY six-inch coil...

Anyway, it's all good!

Steve