Minelab Equinox owners - Question

Kingfish....... No. Not at all. The operating system of the Tarsacci is completely different than Minelab's M-IQ. Once the Tarsacci is Salt Balanced..... it no longer sees (nor is affected) by the wet-salt. Moving saltwater has virtually no affect on the Tarsacci.

steveg........ I have always considered the X-Y Coordinate axis 2-D display...... to be more 'bells-n-whistles' ......than anything else. It has always been in the audio......that would get me to lock up my brakes on a target. I would already know whether or not I was going to dig the target....or not....BEFORE I would ever examine the 2D display.
Yes..... FBS...... and especially M-IQ,,,,,,,,, has a strong propensity to ID a non-ferrous target correctly......with minimal waiver ..... even in close proximity to an iron implement. When you are rotating your body around suspect target(s)....whilst still sweeping coil: If the non-ferrous target is presenting >50% signal strength (over the closely located iron target)..... M-IQ will ID the non-ferrous target correctly..... to a uncanny degree. If the co-locate iron target is presenting >50% signal strength...... than M-IQ will correctly ID the iron target......even to its correct iron conductive ID (as long as unit is in "Multi"). There's very little 'averaging' that is taking place. More of a: GO...........NO-GO scenario.
You guys are spot-on. ---Mike
We have a lot on our plate. Nuff said!

NASA-Tom -- I agree with you that the AUDIO is what causes me to "lock up the brakes" as you put it. NO doubt. But, with FBS, if you hunt "open screen," with no disc at all, and cue your tones off of the CONDUCTIVE side (a very difficult way to hunt FBS machines), then for me, I never got the knack of discerning a deep coin, from certain deep (often bent) nails, BY AUDIO ALONE. When listening to conductive audio, a deep nail would often -- to my ears -- present a sound very similar to a deep coin in many cases. So THAT is where turning to the FE/CO 2D display would help. The clues that were given ON THE FERROUS side, were a necessary piece of information to help determine whether the "good-sounding" audio you are hearing from the convective side, is more likely a masquerading nail (higher FE number), or a non-ferrous target (lower FE number). So, for me, FE-CO/2D was not quite as much "bells and whistles" as it is for you.

So, for me personally, with the Equinox, there are two things I think having FBS-level accuracy (or better) FE and CO numbers would assist with...

1. I believe with MODERATE certainty, that a deep bent nail that is high-toning me, and doing a pretty good job of mimicking a coin audibly, on my EQX, could be better differentiated from BEING a deep coin, by glancing at a FE/CO readout, and analyzing the FE number (or cursor readout) while rotating the target...

2. I believe with STRONG certainty, that a deep wheat cent, or silver dime, that is up-averaging on my EQX into the low to mid 30s consistently (i.e. silver quarter/silver half dollar range), would MUCH MORE EFFECTIVELY reflect the ACTUAL "conductive" ID of mid to upper 20s, IF the machine was algorithmically set up like FBS to offer FE AND CO numbers (where I really feel like the "irony dirt" up-averaging influence on a high conductor could be confined to the FERROUS side, much like it was in FBS, thus leaving the conductive number much less contaminated/much more "accurate."

I will note that in either of these cases, FBS or M-IQ, I am more often than not digging the target EITHER WAY. But for me, it provides a more intelligent/enjoyable hunt, when what I THINK I'm going to dig, pre-dig, based on my machine's output and my understanding thereof, is more often than not correct. Like I said, while most of these targets I would dig EITHER WAY, with either FBS or Multi-IQ, I can say for sure that my ability to "call the target accurately, before I dig it" was definitely higher on FBS, than it is on M-IQ. Yes, the target still gets dug, but there were fewer "surprises," with FBS than with M-IQ. Some of that was due to the slightly better audio on FBS, but not all...some was FE-CO/2D. And therefore, I believe that if FE-CO/2D were carefully designed/implemented into the M-IQ platform, that M-IQ could greatly improve my "ability to call the target pre-dig," with AT LEAST as much accuracy as I could with FBS (if not more...)

Steve



Edited 1 time(s). Last edit at 01/27/2021 08:39AM by steveg.

steveg Wrote:
-------------------------------------------------------
> NASA-Tom -- I agree with you that the AUDIO is wha
> t causes me to "lock up the brakes" as you put it.
> NO doubt. But, with FBS, if you hunt "open screen
> ," with no disc at all, and cue your tones off of
> the CONDUCTIVE side (a very difficult way to hunt
> FBS machines), then for me, I never got the knack
> of discerning a deep coin, from certain deep (ofte
> n bent) nails, BY AUDIO ALONE. When listening to
> conductive audio, a deep nail would often -- to my
> ears -- present a sound very similar to a deep coi
> n in many cases. So THAT is where turning to the
> FE/CO 2D display would help. The clues that were
> given ON THE FERROUS side, were a necessary piece
> of information to help determine whether the "good
> -sounding" audio you are hearing from the convecti
> ve side, is more likely a masquerading nail (highe
> r FE number), or a non-ferrous target (lower FE nu
> mber). So, for me, FE-CO/2D was not quite as much
> "bells and whistles" as it is for you.
>
> So, for me personally, with the Equinox, there are
> two things I think having FBS-level accuracy (or b
> etter) FE and CO numbers would assist with...
>
> 1. I believe with MODERATE certainty, that a deep
> bent nail that is high-toning me, and doing a pret
> ty good job of mimicking a coin audibly, on my EQX
> , could be better differentiated from BEING a deep
> coin, by glancing at a FE/CO readout, and analyzin
> g the FE number (or cursor readout) while rotating
> the target...
>
> 2. I believe with STRONG certainty, that a deep w
> heat cent, or silver dime, that is up-averaging on
> my EQX into the low to mid 30s consistently (i.e.
> silver quarter/silver half dollar range), would MU
> CH MORE EFFECTIVELY reflect the ACTUAL "conductive
> " ID of mid to upper 20s, IF the machine was al
> gorithmically set up like FBS to offer FE AND CO n
> umbers (where I really feel like the "irony di
> rt" up-averaging influence on a high conductor cou
> ld be confined to the FERROUS side, much like it w
> as in FBS, thus leaving the conductive number much
> less contaminated/much more "accurate."
>
> I will note that in either of these cases, FBS or
> M-IQ, I am more often than not digging the target
> EITHER WAY. But for me, it provides a more intell
> igent/enjoyable hunt, when what I THINK I'm going
> to dig, pre-dig, based on my machine's output and
> my understanding thereof, is more often than no
> t correct. Like I said, while most of these t
> argets I would dig EITHER WAY, with either FBS or
> Multi-IQ, I can say for sure that my ability to "c
> all the target accurately, before I dig it" was de
> finitely higher on FBS, than it is on M-IQ. Yes,
> the target still gets dug, but there were fewer "s
> urprises," with FBS than with M-IQ. Some of that
> was due to the slightly better audio on FBS, but n
> ot all...some was FE-CO/2D. And therefore, I beli
> eve that if FE-CO/2D were carefully designed/imple
> mented into the M-IQ platform, that M-IQ could gre
> atly improve my "ability to call the target pre-di
> g," with AT LEAST as much accuracy as I could with
> FBS (if not more...)
>
> Steve

I would agree with that. If the M-IQ had ferrous and conductive numbers, I would own one. I get fooled often by the whispers of deep iron and that little extra tidbit of information would save me some time.. .. if the tones and numbers were not related.

If in fact a unit had the ability to be able to decipher slight, minute, tonal differences verses my own hearing. .. that would be something and we wouldn't have to rely on our own ears for ferrous non ferrous targets.

Brian hit the nail on the head! Truth be known: the electronic architect is configured whereby... the X-Y Coordinate axis 2D display is "SLAVE"...... and the audio is "MASTER". And many times..................... if there is a small nail next to a coin......... the 2D display will talk you out of digging!

Dew and Tom thanks for the info..MDT now sounds incredibly interesting.. However taking extremely long time on the 12" coil. Hopefully that changes soon.

Ya.... I’d like to see it soon. But I’m impressed with the MDT improvements making it waterproof and what appears to be a second coil ... all during this virus. Hoping this coil is kick ass. I’m ready to get one in the water.

I know the coil was supposed to be ready/released around (this past) Thanksgiving. Things are indeed slow. But..... at least..... there's a 2nd prototype coil that is floating around now.,.,.,.,.,., and is in Aarons hands.....up in Michigan. It'll make it's way to (probably) Keith S. and myself sometime soon. This testing will determine quite a bit.......including release-date. I'll keep you guys updated with its status......and performance level. And....................... ultimately......................... its release date.

Odd that coil didnt get to you FIRST Tom. You seem to be a real contributor both in marketing and tech. But i realize they are doing U-tube videos and you try to be neutral and fair to all the companies you deal with. For me .... i dont really need another video from the frozen North as beach guy. That just seems to be another delay ..... i seem to remember a certain detector that didnt get to you until the last min..... then it delayed the release (actually 2 machines) .... but improved the machines.

dewcon4414 Wrote:
-------------------------------------------------------
> Odd that coil didnt get to you FIRST Tom. You see
> m to be a real contributor both in marketing and t
> ech. But i realize they are doing U-tube videos a
> nd you try to be neutral and fair to all the compa
> nies you deal with. For me .... i dont really nee
> d another video from the frozen North as beach gu
> y. That just seems to be another delay ..... i s
> eem to remember a certain detector that didnt get
> to you until the last min..... then it delayed the
> release (actually 2 machines) .... but improved th
> e machines.

A machine that is bragged up as a Salt Water machine, and a new coil is not in the hands of a Salt Water tester. HOW does that even happen?

Doing some backward thinking on the MDT 8000 .
Most will agree its the deepest none PI machine in
saltwater on the market. Now in the dirt, Tom D and Kieth S speak of its ability to go deeper in mineralized soil. So with the bigger prototype coil
seeing more ground and if the ground is on the lower side of mineralization, will it help to see
the target. Because its bonding more soil together.

Opposite of a VLF were a bigger coil may be of little help in hot ground because more minerals equals more masking. Hope this makes sense.

Sorry meant to post on MDT THREAD

If someone can move this thread, please do.



Edited 1 time(s). Last edit at 01/31/2021 05:28PM by gman.

Yes.......this should all be on the MDT thread. But......there is certainly some validity of this data being on the EQX (M-IQ) thread. (((In convoluted fashion))).....let me randomly share more data.

* The intent of sending the proto 12" coil to Aaron first... was...... weather was predicted to be warmer.........and: Aaron shoots good videos. BUT...... weather did not cooperate.... and Michigan in mid/late January is snowed-in. Yes..... a wet-salt environment is a primary interest/concern/choice.

* The reason 'why' the mounting ears on the new 12" MDT coil were moved slightly aft of Top-Dead-Center is: This coil is powerful. It needs to be further away from the feet/body. ((A distant secondary reason: Allows for greater arc; subsequently.....giving greater sweep coverage. , . , . , . , . just like a longer shaft would also do)).

*steveg........ "What if" ..... we could create the X-Y 2D coordinate axis to go one step further.,.,.,.,.,.,.,. and graphically display what the human ear can NOT detect? (((Your words (read: blood) input will not be taken in vain))).

* Facing reality with factual data: The M-IQ EQX platform is more sensitive to tiny gold..... in a wet-salt environment (with a few stipulations)...... over the MDT. Fact. Case-closed. ---- But....... on small gold (and larger)..... especially on gold rings (of any size) ... the MDT is (by far) the trump-card over the EQX. And this is with the MDT having it's original (small) 8x11 coil installed. (((Standard EQX coil is much larger than MDT stock coil))).

* gman brings up some good points. A larger coil 'sees' more mineralization .,.,.,.,.,. and can badly hinder performance in wet-salt and/or bad dirt mineralization. Yes...... you can actually lose depth.....with a larger coil..... in MANY environments. This principle-of-physics holds true on VLF (type) platforms...... to include M-IQ // EQX platform. In bad dirt...... the EQX will actually lose depth with large coil(s). The inverse/reciprocal holds true ....for the Tarsacci. The large 12" MDT coil has already proven/validated/certified greater depth in a wet-salt environment. I have validated/performed such test with the 12" MDT coil. What I have NOT done/performed with the 12" coil....is..... simply: go hunt with it. This larger MDT coil 'proved' itself in wet-salt...... so...... we can only speculate that its performance in bad dirt will ALSO prove to be much greater performance. Remember: The MDT is not exactly a VLF unit. Not exactly a VLF platform/operating-system. Hence; "why" it appears to defy some basic principle(s) of physics. Dimitar (and crew) REALLY put some 'blood' into this 12" coil. ((And Multi Domain Technology)). Lest we forsake. (((Hence; the sudden popularity of MDT technology. A paradigm-shift in O.S. mindset/methodology))).

* On the subject of coils: Most folks are really starting to see that the EQX revolves around its 11" round DD coil. So much so..... that a smaller coil does not present the 'expected norm' in targeted performance. A huge EQX coil ALSO does not hit the 'expected norm' in (((past decades of proven/validated))) performance. The Equinox HEAVILY revolves around its 11" coil.
The MDT went; yet, another notch further......... insofar as... the electronics were built AFTER (and around) the coil. This is 'why' it has been so difficult to create a different coil for the MDT. (((In this case....... the 12" coil))).

But........ on both fronts....... the World might just flip up-side-down.

NASA-Tom --

I think what you are alluding to -- letting the "visual display" offer something FURTHER (regarding intelligence about the target) than what our ears can discern, is tantalizingly exact, in terms of what I'd hope for from a future M-IQ flagship machine.

There are those certain few folks that many of us have come to know in this hobby (I've hunted with a few) who seem to have an uncanny knack of hearing subtle clues, in the audio (likely stemming at least in part from MANY years/hours of experience), that some of us simply can't discern with anywhere near the same degree of skill. It manifests as almost a "sixth sense" that they have, in knowing what to dig, and what not to. And so, taking some of these "barely discernible in the audio" types of clues -- or even better, clues not audibly discernable at all -- and then offering them graphically on-screen, would be TERRIFIC. The audio, set up to "stop you in your tracks," and then video clues that offer "value-added" information/intelligence about your target, seems like the ideal machine, to me.

Steve

What I see Steve .... to often what stops um in their tracts is loud targets. They hunt fast for recent drops.... and miss out on tones they aren’t used to listening. It did help having pitch hold. It clicked with me one day park hunting with an Explorer. It was like what is that..... then I realized there are targets... deep targets I was overlooking. There comes a point that you hope you ID targets to depth and it’s accurate.... even if it upscales/down scales.

Dew -- yep, no doubt there are those people out there! I'm talking though about something a little different. I know a couple of guys like this, but one in particular just had a knack for pulling non-ferrous out of iron. It wasn't that he had a top-notch "unmasker;" he was swinging an AT-Pro at the time. But he knew that machine, and knew how to coax the goodies out from the square nails. He'd hit a target, and call me over, and I'd listen, and rotate around the target, and try my best to hear what he was hearing...and YES, I could hear the high toning in the with the iron grunts, but...many of those "keeper" targets he ended up digging didn't sound any different to my ears, than the high tones mixed in with the iron grunts that were nothing but "false" high tones. He just had an uncanny knack for knowing WHICH high tones amongst the non-stop iron grunts were the ones to dig, and which ones could most likely be written off as "falses." We compared a TON of targets, listening to what each other was hearing. Simply put, he could discern subtleties that I could not...

Steve

This is why one needs to alter there parameters for dig decisions.
I always say the detectorist in a site using a detector familiar to them, and they find few targets, this is the person who is most dangerous with a metal detector (figuratively speaking). You start taking chances. And one has a uh oh moment. And this uh oh moment is planted in one’s brain/ears/eyes.

Won’t be many uh oh moments in virgin sites at all.

Btw, good idea to sweep and walk 360 degrees around every target one plans on digging. Lot of no brainers can be located and dug and not walk around sweeping. But guess what. One could witness one of those uh oh moments when walking around target.
One reason I don’t like volume dig hunts. Take your time and get all the intel you can on all targets.



Edited 3 time(s). Last edit at 02/04/2021 08:30PM by tnsharpshooter.

Steve..... there sure has been improvements in recovery speed as well. Id sure liked a fast recovery on the good ole Explorer...... or even the Xcal. I kind of chuckled when you talked about them hearing things you really couldnt. I used to hunt with a young guy...... he was really good at hearing deep silver coins. Had a knack for it .... but i think also he could just hear what my old ears couldnt. Kind of like the difference in BOSES speakers and an above average speaker. Another thing that moved us forward ..... especially for park hunting was multi tones. People who constantly change machines...... may find it difficult as well. Im a firm believer in .... dont sell a machine until its paid for its self. Sometimes the light bulb just comes on.



Edited 1 time(s). Last edit at 02/05/2021 12:14PM by dewcon4414.

Dew,

Sorry, I had missed your reply. Just saw it now!

Yep, no doubt hearing (especially higher frequencies) deteriorates as we age...which doesn't help!

And, I agree with you on the multi-tones, and really learning a machine's "dialect." There's no doubt that constantly changing machines often means moving on to a new one, before you've fully learned to decipher all the subtleties that your prior machine could offer, through its audio.

Steve

So, I went out for a hunt today, and it was a bit frustrating, due to -- EMI!

I was at a park that I've hunted many times, and on the east side of the park, I speculate that there is some sort of buried power line or something. While it varies from day to day, or possibly even time of day, the EMI in proximity to this side of the park can be really bad. The issue is, on that east side of the park there also lies an old ball field. Due to some dirt moving, I believe (levelling in the outfield over the years), there are some really deep (fringe-depth) old coins there to be had. But -- EMI often precludes reaching them. Today was one of those days.

One thing I've noticed, is that when hunting for shallower targets, you can -- with some concentration -- hunt THROUGH the EMI to some degree, with the EQX. IF you can pick out the "good" chirps from amongst the EMI chirps, enough to get you to stop and investigate, then by using the "Minelab wiggle" you can get the EQX to "lock on" to the target. And in fact, if the target signal is strong enough, the target tones sort of "take over," temporarily, and will almost entirely audibly mitigate the EMI noise, to where all you hear is target. It's an interesting behavior of the unit; audibly, while "wiggling" the target, the EMI chatter audibly disappears entirely. The unit "locks on" to only the target tones. Thus, you can interrogate the target, and make a dig decision, somewhat effectively (again, that is assuming you were able to hear the initial chirp, through the EMI chatter, well enough to have caused you to stop and investigate in the first place).

Especially when the EMI chatter is of the type that has a "pattern" or rhythm to it, you can somewhat listen for tones that differ from the rhythmic EMI noise, and thus still manage to pull out some targets -- IF they are shallow enough. However, I find it much more difficult, and at times impossible, when "hunting deep." First off, the subtle chirps you are trying to listen for as you move along, that would be generated by a fringe-deep coin, are nearly impossible to pick out from amongst the EMI chatter. And then, if you somehow do isolate a "good chirp," those weak chirps are usually "too weak," for the machine to lock onto them enough and "drown out" the EMI, like it can when the targets are shallower/signals stronger. SO, it's essentially fruitless/frustrating, as you can't interrogate the target, as the behavior of the tones you are trying to evaluate is entirely interrupted/contaminated with the random EMI chirps that are mixed in -- so that you can't get any useful target information.

Today was a day when the EMI in this part of the park was too pronounced to "deep coin hunt" effectively, so whatever fringe-depth coins remain in this ball field, will have to wait for either another day, or another machine. Frustratingly, which is an all-too-common occurrence, multiple noise cancels were entirely ineffective at mitigating this particular EMI. That's not to say that the EQX is "poor" with respect to EMI. I consider the EQX to be "at least average," if not above, in terms EMI handling at many sites (at least the AUDIBLE forms of EMI) -- such that I can often run sensitivity higher on the EQX than other units, and not have it suffer from EMI noise. But, at the same time, on the days and in the locations where the EQX IS being affected by audible EMI, I find it more often than not to be largely, if not entirely, unable to mitigate the EMI chatter through use of the noise cancel function. On rather rare occasions, doing a noise cancel will eliminate at least the audible EMI chatter. More often than not, though, noise cancel has little if any effect on the audible EMI chatter, in my experience.

So, my hopes for a deep coin hunt in that ball field were dashed, today...leaving me pining for an effective way to cancel the effects of EMI...

Steve



Edited 1 time(s). Last edit at 02/28/2021 03:04AM by steveg.

Good discussion. Wondering about the large 15” coil being affected by mineralization. Have any large coil users stopped using the larger 15” coil?

steveg........ your timing/experiences with your post....is uncanny! I have limitations as to what I 'can' discuss......and what I can 'not' discuss.
BUT...... your observations are exacting (and well articulated).
Most of the time...... EMI comes in the form of broadband white-noise....whereby....the NC Channels (Noise Cancel Channels) that the EQX (or F75, T2, Impact.....and plenty of other units) possesses........ are very 'discrete' channels; subsequently being applied to 'broadband'. "Discrete" does not work for "broadband"; hence, "why" (most of the time) performing a Auto NC function...... is rendered: ineffective.
Now I hate to bring this up........ but I would rather hurt you with honesty.,.,.,.,.,.,.,., rather than mislead you with a lie. ((If we face the truth.... we will deal with it.,.,.,.,., and 'overcome')). Since you are talking EQX..... I will use EQX for this example. (FULLY applicable for/to other platforms). The EQX has a crude (but effective) LCD depth gauge on the display. . . . . . in vertical fashion. There are 5-triangles that dictate depth. If you detect a target....and only 1 triangle is illuminated...... the target is shallow/strong. If you detect a target that illuminates all 5 triangles..... the target is deep/weak. I use this depth gauge system in totally unsuspecting, reciprocal fashion. Those folks of whom DO use this 5 triangle LCD depth gauge...... use it for: what IS there. I use the depth gauge for what is NOT there. EMI has caused me to function/operate in such capacity. Because we have NO idea how 'bad' EMI truly is....... is what has caused me to employ the depth gauge in a unintended design fashion. Here is my recommendation:
When you hunt a site..... PAY ATTENTION to: "Am I detecting any 5 triangle depth targets?" ------- If EMI is even worse: "Am I even detecting any 4 triangle depth targets?".

And to expose the deadliness of EMI one (unsuspecting) step further:
Hey. This site is quiet. I can hear no EMI !!! How nice! I can run Sens quite high! --------- Hmmmmmmmmm. Then WHY am I not detecting any 5 triangle depth targets and no 4 triangle depth targets? Hmmmmmmmmmm.
Answer: SILENT EMI

In this electromagnetic detecting World........ EMI is THE most crippling external element of hinderance.

You may hunt a site on a different day..... with some 'newly discovered' program that you want to test. Or.....even with a different detector. THEN you claim: THIS program (or different detector) is superior!!! (((Only to learn: It was merely a different day..... with different (less) EMI conditions.......,,,,,,,allowing the electromagnetic device (the detector) to perform closer to engineering design intent))).
-----------------------------

FloridaSon...... yes. The larger 15" coil does incur greater blowback/flyback in mineralized ground....... subsequently inhibiting performance.

NASA-Tom, it sounds like this is being looked at heavily, which may hopefully result in a machine that handles EMI more successfully. That would CERTAINLY be a welcome innovation!

Steve

Steve.............a few days ago.......I finished some 'crazy' testing.......,,,,,,, just to resolve/mitigate a theory. Over a Decade ago...... I started a thread titled: Rcpt Ack of F75 LTD Proto. In this (long/huge) thread, I heavily covered the EMI subject/incursions. Some folks (independent of each other)...... had tested a theory......and even contacted me...... with some unique testing resultants. SOOOoooooooooo......... I decided to test the theory myself. I just finished the exact same type of testing on a Nokta Impact and a Fisher F75. In several different EMI-riddled sites....... I wrapped the coil wire in thin aluminum foil. I then wrapped the control-head (electronics) in aluminum foil. All for the purpose of testing (end-resultant) EMI mitigation theory(s). In a nutshell....... the F75 expressed zero delta/difference in EMI strength.....with (or without) aluminum foil shielding installed. The Nokta Impact 'appeared' to show a difference at 2 (of the 5) different sites......when (only) the control-head was wrapped in aluminum foil. Additional testing (with all eyes on the Impact.....and aluminum foil covering the control-head)......... then expressed REVERSED end-resultant.,.,.,.,.,whereby...... REMOVING the foil covering expressed reduced EMI. I then tested: turning the unit 'off'. Then turning the unit 'on'......... in one-minute intervals...........for many cyclings. This too....expressed the same 'changes' in EMI encounterings.

Conclusion: EMI is not a 'constant'. EMI can 'vary'.....from minute-to-minute. Installing/removing aluminum shielding...............AND.............. turning the unit off and on...in 1-minute intervals....expressed the exact same end-resultant. Sooooo......... due to uncontrolled variables in the equation (EMI conditions varying.....minute-to-minute).,.,.,.,.,.,.,. voided/zeroized testing accuracy/validity.

With all of my testing, I have confidence that nearly all EMI enters the detector through the coil. (I believe I expressed exactly this......over a Decade ago).

On and off EMI possibly means our sites may have a lot of skips or undetected areas scattered about. = missed good targets. Goes with the old saying that sites are never hunted out.
Is their a gadget that could be installed on the detector that senses when EMI is affecting the unit to the point it's not detecting? Hmm. Would be great to know.

Tom..I personally found the Deus with a wireless coil to be more influenced by EMI at a few of my sites. A great detector. I'm not bashing it. But I would have to drop the frequency and sensitivity to make sense of the signals. One reason I never showed interest in the High frequency coil.

goodmore....... correct! And.................... the more 'wireless' you run (ie..... wireless headphones, wireless coil....etc......) the greater the EMI susceptibility. I NEVER use wireless!!!..... for this exact (verified) reason.

Steve..... in a short answer: No.
What may cause EMI to a EMI meter....... may not be any of the types of EMI that cause interference to a detector. AND...... different detectors encounter EMI differently. One detector may incur slight EMI at a site.....and another detector may be severely crippled at this exact same site. , . , . , . , . , . all due to operating freq(s) of the particular detector.

EMI/silent EMI is extremely crippling.
EMI is (usually) the primary factor as to 'why' you may rehunt a exact-same-site..... and have 'magical' performance resultant(s)........ because you hunted it again...but THIS time...... EMI was lower. Silent EMI is even worse to measure!

Tom.
How does Silent EMI.... . . disrupt the electromagnetic field of the coil. .. . . and the receive coil doesn't pick it up to send to the head, to put out a signal of the disruption? The EMI we hear certainly is picked up. I know you stated there are all kinds of EMI.

The silent EMI does something. . . and whatever it does . . .it keeps the detector from doing its job. How does it kill depth without being detected ?

Does EMI, silent or otherwise, affect, change, or shut off, the ground balance setting? If it does, the detector would run noisy, I would assume.

Silent EMI baffles me. A detector works when the EM field gets disrupted. But Silent EMI shuts down the field (disrupts it) but we don't get a signal. Hmm.



Edited 1 time(s). Last edit at 03/03/2021 05:48PM by ozzie.

Steve...... that is a VERY valid question.,.,.,.,.,., especially since it is NOT even close to being 'obvious'. And......... I can only explain some of the mystery.

A metal detector gives you a 'beep' when it detects a "change". If you MOVE a coin (or any metallic object) past the coil...... it see's/detects the 'change'. If you hold the coin perfectly still..... right in front of the coil. . . . . . it will not detect it. (Although it is interfering a bit with the detector). If the coin is a fairly large coin ....(say....a Half Dollar)..... and you hold the coin perfectly still; yet, right on top of the coil....... the detector may give you an 'overload' signal....... even though the coin is NOT moving.
A lot of EMI comes in the form of random jagged spikes (bursts) of electrical energy that is close to the operating frequency of the detector. You can hear these sudden 'spikes'...... because it is a 'change' to the norm....(the base-threshold)....... to the 'null'.......and the detector will chatter.
If EMI also comes in the form of a 'steady' energy (of continuous amplitude/wave)........ the detector does not audibly report a "change"...... because the interference is 'steady'. There is no 'sudden': ramping-UP.....then sudden ramping-DOWN energy. It poses no 'ramp'. So the detector does not 'beep'.

Imagine: You are in a room having a normal conversation. Then........ someone turns on 3 fans in the room. The fans are fairly quiet.......not really noisy. You can still hold a normal volume conversation in the room. BUT..... the car passing down the street outside..... can no longer be heard..... due to the steady (white noise) of the fans. After a while...... you may never even notice that the fans are running. Never even notice the noise. Because it is a constant/steady hum.

There's another form of EMI that causes other electronic circuits to be 'inhibited' in performance..... internally WITHIN the electronics......,,,,,,,......that is nowhere near the audio portion of the circuitry...... that will kill the performance of the detector; yet, produce NO audible noise in the headphones. I'll spare you all of the technical's of this one.

And......... EMI also comes in many other forms. (Again..... sparing you the geek/nerd details)!

Did I shed any light..... or make it worse?!

NASA-Tom,

I am going to take just one baby step into the nerd/geek details, just for my own curiosity, and hopefully don't annoy anyone with this slight veering of the thread into a rabbit hole.

First, here's my understanding, please correct if wrong...

A detector transmits electromagnetic waves, of known electrical "properties" (frequency, etc.) When this electromagnetic field moves across an electrically conductive (metal) object, (or vice versa -- a metal object moves through the electrical field), this induces electrical current in the metal object. The electromagnetic field that results from this current flow in the metal object (eddy currents), is of "different" electrical properties than the transmitted electrical field. The coil then receives, and the machine measures, the new, resulting electromagnetic waves. Based on the machine's measurements of the changes in the electrical properties (phase for one thing) of the received electromagnetic waves as compared to the transmitted waves, are then run through algorithms and finally reported audibly (tones) and visually (VDI) to the user.

If my understanding is correct, then...

Does that mean that if I pass over a dime, and the machine "sees" the "induced" electromagnetic energy emanating from the dime, and reports the differences between the "transmit" energy and the "receive" energy to me as a "26" VDI, that THEN...IF a source of EMI is producing audible output on my machine, that also corresponds to "26" VDI, then I can conclude that the reason both of these scenarios produce "26" VDI is because the electromagnetic energy we are calling EMI, just so happens at that time to be of the same "electrical properties" as what would be induced in a dime, by the coil's transmitted EM energy...such that the machine sees them both as being "the same thing" (hence the 26 VDI for both)? On one hand, it seems obvious and simple that this MUST be the case, but then I wonder if there are other things that are more complicated than I understand, that would make that an incorrect assumption...


Steve

NASA-Tom Wrote:


Tom, that was a perfect simple answer for my simple mind. Especially the steady energy wave compared to the perfectly still coin.

It does pop another question. .. one that I can check out myself. .. . .If there is a "still" metal object near the coil with no signal and no overload, and if you run a coin in motion past the coil, will it give a signal..and.. will it ID the coin properly?

The fans white noise blocking out the cars reminds me of noise cancel headphones. Thank for taking the time to answer, they were great!