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Lifting Coil - Iron Burp


DaveP

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9 hours ago, Chase Goldman said:

 

Frankly, life’s too short and swing time too precious to seek out all the answers to quirky detector behavior, but that’s just me.

Thanks Chase, and I have to agree 🙂

I did some checks yesterday on a pasture field. IB = 0

I hit a couple of targets that gave solid 14-15's in both directions. Lifting the coil gave -ve 1-3. Both targets were degraded shotgun carts. When I popped the plug out I checked the hole and no signals at all. Checked the now upside down plug and got the same signals left right and up/down.

Another target with a solid 16 gave no -ve's and turned out to be a victorian halfpenny. It suggests the -ve's and iron burps are due to the target and that seems to be all of my experience so far. 

Does it matter - not really as all of those targets are still coming out of the ground. What really happens, especially on a quiet field is "good two way signal - hooray!". Lift the coil and get a burp and it's a wave of disappointment as I know what's coming 😩

It was more just the curiosity of what is really going on. But as you say "life's too short........"

 

Chris

 

 

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On 3/12/2021 at 4:32 AM, DaveP said:

I use both tracking and non-tracking but hope to get out this afternoon and will double check both if I get a similar signal.

What makes you ask?

Hello Dave

If you use the "Tracking" Ground Balance it is possible to alter the tonal and total loss of the signal on thin Non-ferrous objects the likes of weathered shot gun cartridge cases and hammered silvers  if you dwell too long on sweeping the coil over the signal whilst in "Tracking",  on a hammered silver you can literally loose the signal altogether as the procedure of GB adjustment not only eliminates the ground noise it will eliminate the signal from the thin hammered silver, here in the UK it is best to either set the GB at 0 (Zero) or myself I prefer to every now and then carry-out a ground balance.  You may find that the blurp noise is a result of when lifting the coil away from the signal is because of the "Tracking" attempting to hang onto the remnants of the poor signal.  On some of the forums people say auto tracking GB will discriminate out good targets.

Here below is a link to an excellent youtube video of how to set the different Ground Balancing settings.

Good Hunting   Randy Dee

 

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1 hour ago, Randy Dee said:

  if you dwell too long on sweeping the coil over the signal whilst in "Tracking",  on a hammered silver you can literally loose the signal altogether as the procedure of GB adjustment not only eliminates the ground noise it will eliminate the signal from the thin hammered silver,

Thanks Randy and interesting stuff. Setting the balance in different modes isn't a problem and I do re-check but I've never tried it at zero. I'm also in the UK and will take note of that. The ground I'm on is not very productive but the hammered I've had have been good clear signals. I'll have another wonder over the more productive area with GB at 0 to see if I've missed anything. Although on other targets (not hammered) I've found a few extra swings often develops the iron component of the signal. 

At the end of the day if it's a half decent signal it's coming out of the ground but thanks for the help - every day's a school day.

Chris

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11 hours ago, Randy Dee said:

If you use the "Tracking" Ground Balance it is possible to alter the tonal and total loss of the signal on thin Non-ferrous objects the likes of weathered shot gun cartridge cases and hammered silvers  if you dwell too long on sweeping the coil over the signal whilst in "Tracking",  on a hammered silver you can literally loose the signal altogether as the procedure of GB adjustment not only eliminates the ground noise it will eliminate the signal from the thin hammered silver, here in the UK it is best to either set the GB at 0 (Zero) or myself I prefer to every now and then carry-out a ground balance.  You may find that the blurp noise is a result of when lifting the coil away from the signal is because of the "Tracking" attempting to hang onto the remnants of the poor signal.  On some of the forums people say auto tracking GB will discriminate out good targets.

Randy - have you ever experienced this phenomenon first hand on the Equinox?  While this behavior is common with some other detectors that use a tracking gb scheme (I experienced it on the Deus before XP implemented a ground tracking sensitivity adjustment in version 5.X and above Deus firmware), I have never experienced this with Equinox for a range of targets.  I have tried to force it to happen with a number of different target types including a hammered coin, gold coin, pull tab, bottlecap, silver coin, copper coin, brass button, lead minie ball and even a rusty iron nail.  I have tried to force this to happen with Equinox in GB Tracking and regardless of the target type, target depth, or ground conditions, have never successfully been able to cancel out a target.  On Equinox, GB tracking is somewhat sluggish and appears to only react to changes in ground mineralization.  I have taken the Equinox to GB, set GB 0 in soil that registers typically in the 70's and have swung and pumped the coil until tracking "catches up" with the actual ground phase setting.  It takes awhile for it to achieve balance in this manner (rather than pumping the coil in auto GB).  I have then swung over numerous targets with tracking on and the GB reading NEVER changes in response to the target in the ground.  Never.

Since I have never been able intentionally or unintentionally to get a target signal to cancel out under various conditions while GB is in tracking, my conclusion is that this tribal knowledge item has merely been carried over from people's experiences with other detector ground balance tracking schemes.

While I acknowledge the phenomenon on other detectors and have experienced it first hand with Deus, until I see a credible video demonstrating Equinox cancelling out targets when in GB in tracking, I consider this to simply be an unproven myth as far as Equinox is concerned. 

BTW - This is posted with all due respect, Randy.  I understand where the notion of GB tracking target cancelling comes from, I could be wrong and just haven't discovered the right combination of variables to make it occur, but in reality, I just don't think it is a legitimate issue with the Equinox.  

I am willing to be convinced - someone point me to a video demonstrating it actually happening with the Equinox.

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8 hours ago, Chase Goldman said:

I have taken the Equinox to GB, set GB 0 in soil that registers typically in the 70's and have swung and pumped the coil until tracking "catches up" with the actual ground phase setting.  It takes awhile for it to achieve balance in this manner (rather than pumping the coil in auto GB).  I have then swung over numerous targets with tracking on and the GB reading NEVER changes in response to the target in the ground.  Never.

Chase, this is an interesting discussion.  I was always under the assumption that if I was detecting a site with a very high amount of ferrous/non-ferrous targets (numerous targets on every swing of the coil) that auto GB tracking on the Nox would not properly be able to accurately ground balance one’s machine (it can’t tell difference between ground and an actual target), and in such a case, locking the ground balance  (after GB’ing a clean area of ground) would provide a more “sensitive” machine to the deeper/fainter signals on the fringe of detection.  

I dug 4-5 deep wheat pennies the other day with my Nox in a small area I had detected thru at least 10 times before with my Explorer SE over the years.  Remarkably, I could not hear these deep wheat penny signals when I bumped the ground balance from 7 to the upper 30’s.  Now, these targets were in a high EMI-riddled zone, so I was fighting EMI instability while listening to the faintest inkling of a repeatable signal above 20 VDI on the Nox. At a ground phase value of 35 or higher, the deep wheat penny targets would not give a repeatable signal.  I then turned auto ground balance on and pumped my coil up and down in the general area....I had a hard time trying to find a clean area of ground to get an accurate ground balance..sometimes I would get a reading in the 30’s after pumping the coil, other times in the 40’s...I stood in the same place to try and find a clean area of ground, and on the 3rd or 4th try, I was able to get ground balance down to a 7 (which was my initial GB setting when I first began my hunt that day (I was 50 ft from where I first turned my machine on, and did my initial ground balance).  At GB setting of 7 or lower, I was able to get a barely repeatable signal (I had to wiggle coil very narrowly and from only one swing plane) on those 4-5 deep wheat pennies to get a “dig me” signal....The “dig me” I heard, I surmise, would not have been a “dig me” signal for a lot of hunters....especially with all the EMI (underground electrical from light poles) barking on it...I’m fairly tolerant to a high level of signal noise from all the years I have swung an FBS machine at 75-100+ yr old urban sites.  Still amazing that the Nox picked these targets from this area I had detected over the years numerous times with my older machine.

 

The reason I wanted to change my ground balance value was that at the value of 7 (my initial value), I was hoping that I might possibly be able to hear the target a little better if I tried ground balancing again before swinging over the signal another time...It was enlightening to find out my signal had worsened when the ground balance value was increased.

I also wanted to ask you if a high level of EMI in a general area would affect the way the Nox ground balances when pumping the coil up and down (while the machine is singing an EMI melody 😆) ???

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Hello Dave here below is a link to an excellent article on the disadvantages of detecting using the "Tracking" Ground Balance, there is a lot of input from current members of this forum and well worth a read through.

http://www.dankowskidetectors.com/discussions/read.php?2,140280,140289

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On 3/14/2021 at 8:12 AM, Randy Dee said:

Hello Dave here below is a link to an excellent article on the disadvantages of detecting using the "Tracking" Ground Balance, there is a lot of input from current members of this forum and well worth a read through.

http://www.dankowskidetectors.com/discussions/read.php?2,140280,140289

Randy - thanks for the link.  Yep.  I read that thread.  Most everyone there is speculating or commenting based on their experience with other machines (CTX, GPX, Gold Monster, SDC, Deus).  Dave is the only one who actually did any testing or experimenting.  He also did a video which showed how slowly GB tracking responded to soil conditions which concluded that you should do an initial Auto or Manual GB at your site to "get GB in the ballpark" if you intend to use GB tracking.

Again, a lot of folks (including Andy Sabisch in his Equinox Handbook - full disclosure: I am a content contributor to this book) have kept this notion alive on Equinox that GB tracking cancels target signals.

I just don't see it happening, but am going to continue to experiment, especially in light of Raphis' discussion above.  While he wasn't seeing an issue with GB tracking cancelling a borderline target signal, he was definitely seeing an effect on target signal quality depending on the GB setting.  So more work to be done on this.  

My experiences on GB:

GB primarily affects ground noise only (as stated in the manual), and as such may typically only affect your ability to detect effectively with no ferrous discrimantion (may be countered by Raphis' experience where a biased GB setting actually affected the target signal).  

Default GB setting of "zero" may not be sufficient for all soil conditions in reducing ground noise and there should be no downside to getting a precise and accurate GB via Auto or Manual GB in all soil types at the outset of your session to dial GB in optimally.  The key here is getting an accurate GB reading/adjustment and that does require pumping over clean ground.  I often use Pinpoint mode to identify true iron targets that may be lurking beneath the coil in highly mineralized ground that may be constantly giving ground noise ferrous returns - resulting in the "cannot find clean ground to GB" situation.  Though there are truly bed-o-nails patches that exist where you cannot accurate GB in that patch such as what Raphis encountered above.

Users have frequently misinterpreted the ML guidance regarding the "0" GB default as the optimal setting for most situations to mean that there are situations where an Auto or Manual GB can result in a suboptimal setting - I believe this to be patently false.  There is no situation where doing a proper Auto or Manual ground balance will result in a setup that is less optimal than the default "0" setting.

Tracking GB has little proven downside to performance (the disappearing target notion is unproven in my experience).  Tracking GB is sufficiently "sluggish" and tuned to detecting changes in actual ground mineralization, that I have never seen it actually overreact (or react for that matter) to an in ground target signal.

 

On 3/13/2021 at 7:54 PM, Raphis said:

I also wanted to ask you if a high level of EMI in a general area would affect the way the Nox ground balances when pumping the coil up and down (while the machine is singing an EMI melody 😆) ???

Not sure about that one and not sure how I would even go about testing for the effect (I would have to have a means to switch the EMI off and on to get a comparative baseline) but I am probably going to take a more comprehensive look at the GB feature as things warm up here and I can take the time to experiment more.

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18 hours ago, Chase Goldman said:

Randy - have you ever experienced this phenomenon first hand on the Equinox?  While this behavior is common with some other detectors that use a tracking gb scheme (I experienced it on the Deus before XP implemented a ground tracking sensitivity adjustment in version 5.X and above Deus firmware), I have never experienced this with Equinox for a range of targets.  I have tried to force it to happen with a number of different target types including a hammered coin, gold coin, pull tab, bottlecap, silver coin, copper coin, brass button, lead minie ball and even a rusty iron nail.  I have tried to force this to happen with Equinox in GB Tracking and regardless of the target type, target depth, or ground conditions, have never successfully been able to cancel out a target.  On Equinox, GB tracking is somewhat sluggish and appears to only react to changes in ground mineralization.  I have taken the Equinox to GB, set GB 0 in soil that registers typically in the 70's and have swung and pumped the coil until tracking "catches up" with the actual ground phase setting.  It takes awhile for it to achieve balance in this manner (rather than pumping the coil in auto GB).  I have then swung over numerous targets with tracking on and the GB reading NEVER changes in response to the target in the ground.  Never.

Since I have never been able intentionally or unintentionally to get a target signal to cancel out under various conditions while GB is in tracking, my conclusion is that this tribal knowledge item has merely been carried over from people's experiences with other detector ground balance tracking schemes.

While I acknowledge the phenomenon on other detectors and have experienced it first hand with Deus, until I see a credible video demonstrating Equinox cancelling out targets when in GB in tracking, I consider this to simply be an unproven myth as far as Equinox is concerned. 

BTW - This is posted with all due respect, Randy.  I understand where the notion of GB tracking target cancelling comes from, I could be wrong and just haven't discovered the right combination of variables to make it occur, but in reality, I just don't think it is a legitimate issue with the Equinox.  

I am willing to be convinced - someone point me to a video demonstrating it actually happening with the Equinox.

Yes I have experienced this phenomenon and I have explained the phenomena in a thread dated back in February 12th 2019 in post 4 in exposed in the link below. Many other UK detectorists have suffered the same issue and reported on our local detector forums.

 https://www.detectorprospector.com/forums/topic/8706-problem-with-equinox-600/      

 

 

 

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9 minutes ago, Randy Dee said:

Yes I have experienced this phenomenon and I have explained the phenomena in a thread dated back in February 12th 2019 in post 4 in exposed in the link below. Many other UK detectorists have suffered the same issue and reported on our local detector forums.

 https://www.detectorprospector.com/forums/topic/8706-problem-with-equinox-600/      

 

 

 

Randy, thanks.  Try as I might, I cannot make this intentionally happen if Tracking GB has settled into the actual ground phase setting.  If Tracking GB is still "on its way" then anything can happen.  That's why I get it in the ballpark first with an Auto GB (on clean ground) then turn on tracking.  As long as the ground is stable, I cannot get targets alone to change the GB setting.  Just my experience.  I will pay more attention to this under various site conditions but so far, it has been a non-issue for me, especially in in hot soils where GB tracking saves a lot of time keeping the detector running quiet in no disc mode.

Wouldn't mind seeing someone actually visually document this phenomenon with Nox.

Thanks, again.

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7 hours ago, Chase Goldman said:

The key here is getting an accurate GB reading/adjustment and that does require pumping over clean ground.  I often use Pinpoint mode to identify true iron targets that may be lurking beneath the coil in highly mineralized ground that may be constantly giving ground noise ferrous returns - resulting in the "cannot find clean ground to GB" situation.

Chase, would you mind detailing how you do this.  The Eqx's 'active' (my word) pinpointing is counterproductive for my use.  First, if you turn it on over a strong target (iron or otherwise) then it won't indicate a weaker target as you swing over that.  Second, it has that very annoying feature of dynamically reducing sensitivity as you pass the coil over a target.  On the surface it seems like these two properties would make it hard(er) to find a quiet piece of ground where you can pump and get a good ground balance.

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