Minelab Equinox owners - Question

Steve........ when a metallic target is passed by the coil...... the "BALANCED FIELD" is disrupted (read: no longer 'balanced'). This causes a distortion to the balanced field (ie.....imbalance). Then..... there is a measurable 'phase-shift' that can be captured. This is what allows for a conductive "ID".
When the coils field is 'balanced'..... this is called: coil "null". The coil will not detect itself......because it is in a 'null'.
EMI is not necessarily ID'able in a conductive spectrum foray. . . . . . . as far as ID'ing (with conductive numerical VDI ID's). There is 'some' truth to --discrete EMI ID-- yet, most EMI is merely broadband white-noise. Causing random/spurious 'splattered' ID's......that are absolutely meaningless. Yes...... we have certainly seen/witnessed/experienced (in some locales) whereby....... EMI presents a synchronous-rhythmic pulsing PRF with a very discrete VDI ID. This may lead you to believe that you will not detect targets within the exact ID window of the EMI ID's..........but all other ID DIFFERING targets: are detectable. NOT true. EMI will also 'shut-down' the detection of ALL targets...... that are 'at' (or below) the signal-strength of the pesky EMI strength. In radio terms: If you are incurring 20db of EMI.,.,.,.,.,.,.,., your detected targets will need to be 21db in signal-strength...... or stronger. (((To make matters worse....... the operator may NOT be able to audibly detect AND discern a 30db signal-strength target......in/at/around/amongst the machine-gun fire of EMI audio reports))).

Steve....... another valid question. In short: Yes. In many cases...... if you hold a (example) = Zinc Penny at ............say.......... 6" from the coil.....,,,,,,......,,,,,,,.......,,,,,,,.......then you pass ANOTHER Zinc Penny back-and-forth past the coil....... it'll "most-probably" detect it. BUT....... several problems will ensue. One of the problems is ..... the coils field will have null spots....and hot spots.,.,.,.,.,.,., due in full to the stationary Zinc Penny. There will also be some phase-angle 'skewing'......and targets can/will ID differently.

NASA-Tom,

Thanks for the detailed answer. So, I was a bit off in my understanding. It is then correct to say that the induced current in the target is what CAUSES the "imbalance" in what would otherwise be a balanced field, yes? And, since you only discussed the phase shift, does that imply that a phase shift is the ONLY alteration to the energy field that the inducing of current in a metal target causes? In other words, is it being implied that there are not any OTHER alterations (in frequency, or amplitude, or other EM wave properties) that occur, which could be exploited to aid in target ID? OR -- are you simply saying that while other changes to the transmitted electrical field ALSO occur, it's the phase shift specifically that is used to determine conductive ID?

Steve

Steve........ it is not so much the induced current INTO the object; but/rather....... the disruption of the balanced field due to the 'interfering' metallic object. And......yes. There certainly IS more ways to skin-a-cat......in order to ascertain more data. There are time-decay-rates of diamagnetic, paramagnetic.....and especially ferromagnetic metals whereby the hysteresis (magnetic susceptibility) can be measured in a domain........ in order to generate target ID. Even by virtue of NO hysteresis in a (by definition) true diamagnetic metal (((something that absolutely rejects/resists being magnetized)))..... IS a sign..... IS a 'signature'..... of "type" of metal (and subsequent phase-angle/phase-shift ID) that can be analyzed. With current technology...... this is performed with Pulse Induction type units. Pulse delay (coupled with receiver On/Off duty cycles) is where we start to collect data.
Amplitude merely measures the strength of the signal. (((How much does the 'balanced-field' become disrupted))). Due to NDA's....... I'm unable to speak too much further; yet, your questions may very well 'trigger' something/someone to think "differently". (Read: Epiphany).

David (TNSS) brings up a good point (and good capture) in his latest video....... with a high-conductor masked by/with birdshot............. coupled with (selectable) single frequencies. His: "Visible for the human eye" air-test...... is valid. It is ALSO valid in low-mineralization dirt. ----Where things become more complex...... is in dirt that is heavier than low-mineralization. First............................... a single-frequency detector (or a detector that is deliberately placed in a single frequency) is "ID handicapped" in lateritic soils. This is akin to the old-fashioned, proverbial: high-beams in fog .....analysis. It is also akin to having sight in only one eye. Perception and depth are badly skewed. With two eyes..... you see in stereo.,.,.,., with full perception and depth 'realized'. If you simultaneously run two (or more) frequencies..... you are seeing in stereo......and acquiring MUCH better ID abilities. Yes....... you can run one (lower) frequency..... with the intent of possibly unmasking a high-conductor ...that is masked by a low-conductor. BUT...... a single frequency has higher propensity to being attenuated in real dirt........AND..... if there is mineralization.......ID's will be much more readily skewed.
And this is where the Tarsacci comes in. It operates under the principality of 'time-domain'. Even though the MDT "looks" to be a single-frequency detector (Heck: you gotta select a single-freq; ie: 6.4Khz, 9Khz, 12Khz or 18Khz)......... so this REALLY "looks" like you are running a "single" frequency. How else are you supposed to think?! BUT........ the reality is: You are not selecting a single frequency. You are actually selecting a domain of time (time-domain). You must NOT think in the capacity of "VLF"..... but/rather: a technological paradigm-shift ...... that does NOT fit within the confines of old & programmed thought-process(s). The older you are........and.........the longer you have been detecting: = the more DIFFICULT it is to break out of "old-ways-of-thinking". (Hence......the true definition of: Paradigm-Shift).

NASA-Tom,

That was a fabulous post. SO informative.

Yes, I had forgotten about "time domain," when I asked my question about what other characteristics of the changes in the electrical field could be measured and exploited for ID purposes. I was thinking specifically "EM wave" properties that might be altered (as you mentioned, when you brought up amplitude). But -- focusing on hysteresis (as Pulse machines, and apparently to some degree the Tarsacci, do), is obviously a slightly different "alteration of the EM field" that is being analyzed for clues" within certain platforms/approaches.

I guess in my mind, I just have to believe that BEYOND our ability to hit a target with a pulse of EM energy and look at "decay" (PI units) or to hit it with EM energy and measure "phase shifts" (VLF-IB units), or to hit it with MULTIPLE different frequencies and then look at DIFFERENCES in phase shifts from each of the different transmit frequencies, that there just HAVE to be OTHER ways to glean information. I just feel as though there is SO much data that could be exploited. Why just phase shift, or hysteresis? There are many more characteristics that could be examined, no?

Look at Doppler radar...Doppler radar can give very precise measurements of how far a target is from the radar, and what direction and speed it is moving, simply by using known characteristics of the transmitted EM energy and then examining CHANGES in these known characteristics, as the EM energy interacts with "targets" (precipitation particles) and then returns to the radar to be sensed and measured. Now, by employing dual-polarized Doppler radar (EM transmissions with waves along two different axes), we have learned how to be able to tell if the precipitation particles are large or small, uniformly shaped or all different shapes, water-coated ice or liquid water, and on and on and on, JUST BY EXAMINING the returned EM energy after it has interacted with the targets.

BUT -- we have now even learned to actually, conclusively detect a TORNADO -- using dual-polarized Doppler radar. NOT simply the velocity of the precipitation rotating around the tornado which can be gleaned from "standard" Doppler radar, which is the more "traditional" way of implying that a tornado may exist. Instead, we can tell whether damage is occurring at ground level, just by analyzing the characteristics of returned EM energy. How? Well, we know that raindrops, or snowflakes, or other meteorological targets, are usually of a certain size and orientation, and move at certain speeds, thus creating a rather "uniform" field of radar returns (again -- all of this is information that can be "gleaned" simply by examining the characteristics of the returned dual-polarized EM waves after interacting with these particles). So, we know what the "normal" characteristics of returned EM energy look like -- and in a precipitation field this uniformity of particle size and shape can also said to be a "well correlated" field of returns. Size and shape of meteorological particles are usually "well correlated," i.e. high "correlation coefficient."

But, what might it mean if, while analyzing the characteristics of the returned energy (specifically, this "correlation coefficient"), we see not HIGH correlation coefficient (small objects of very uniform size and shape), but instead our analysis indicates a small area of very LOW "correlation coefficient" -- i.e. EM radiation that has interacted with objects of very "unusual" sizes, and a wide range of different shapes and orientations, thus creating a very non-uniform, chaotic field of returns (again, all this information inferred by interrogating the returned EM radiation). WHAT MIGHT THIS MEAN? Well, this allows a conclusion, with a very large degree of accuracy (when combined with traditional "velocity" information), that we are seeing the debris -- the damage...trees, leaves, shingles, boards, etc. -- being lofted by the tornado, interacting with the transmitted EM energy, and sending back to the radar very "uncharacteristic" but "exploitable" information (low correlation coefficient) that suggests debris lofted in the air. Just by examining the characteristics of the returned EM energy, we can infer ALL of these things. SO -- my point is, the fact that simply by examining returning EM radiation, and analyzing the ways the EM wave characteristics DIFFER when 1). trees and shingles are flying through the air at 150mph, versus 2). snowflakes or raindrops are falling, at much slower, known speeds, we can thus "see" a tornado...would lead me to believe that there is MUCH more that can be done to ID can slaw vs. a gold ring...just by exploiting characteristics of EM radiation emanating from targets. I know that radar, and the way metal detectors "transmit" and "receive" are not entirely "apples to apples." My point only is that I would think (and maybe this already happens) that by EXPERIMENTING (using data, and statistics, and "machine learning," etc.) that there would be useful patterns in there, that could be incorporated into future "ID algorithms," just by statistically "mixing and matching" various measured quantities within the received EM energy, to see if there is "predictive" value there, that was perhaps unknown or unrealized before. It just may take some creative, out-of-the-box thinking, as you noted.

Meanwhile, your analogy about VLF being like "mono" and multi-freq being like "seeing in stereo" is a terrific analogy that immediately "clicked" with me. It immediately illuminated what I had in my mind "sensed" or "suspected" regarding FBS for instance. I would swear, without knowing HOW FBS works, that the "stereo" view of targets, using different frequencies, puts very nicely into words what I had always sort of envisioned what must be happening, in my mind. I concluded -- by getting used to how FBS behaves -- that instead of irony dirt "contaminating" target ID when using single freq, that instead the use of FBS's multiple frequencies somehow algorithmically sort of removes some of the iron-soil-contamination of a non-ferrous target's ID, and sort of "drops" this iron contamination over into the "FE" bin, leaving the "CO" bin relatively uncontaminated...

Anyway, in my mind I could sort of see what seemed to be happening, but your "mono vs. stereo" analogy really drives that point home for me...maybe the word "comparator" that some here have used, is not quite correct, but something like that is almost certainly at work, and your post here really helps clarify some of the lingering murkiness in my brain.

Finally, on the Tarsacci, so are you implying that selecting a certain "kHz" on the Tarsacci is somewhat analagous to selecting the pulse delay on a PI unit -- such that "lighting up" a target with one frequency leads to different hysteresis behavior?

Could the TYPE OF METAL the target consists of also play a role (i.e. how "resonant" the target's metal composition is to the selected frequency, possibly resulting in an alteration the "strength" of the induced current, and thus maybe altering the hysteresis rate)?

Forgive this somewhat rambling post, but your message stirred up a bunch of thoughts in my mind that are bouncing around...LOL!

Steve



Edited 2 time(s). Last edit at 03/06/2021 09:52PM by steveg.

You know part of what baffles me is when the engineers draw this tech up on paper. How do they actually test to see added performance benefits? What do they have setup maybe readily at their disposal to verify improvement ? Besides maybe using in the wild and comparing to other model detectors. Guess maybe I will never know. And reckon does say Minelab engineers realizing weaknesses of prior engineered platforms drive them in their thinking with engineering of newer platforms?



Edited 2 time(s). Last edit at 03/06/2021 01:30PM by tnsharpshooter.

Steve....... you've probably heard (read) for a dozen years......where I've preached about 'density'....... and the O-Scope signatures thereof.......(to the point of: folks are sick of reading it!!!). Because we are in a new crux of electronic mindset ...... it may behoove me repeating.

Even on a simple single freq VLF....... if you pass a piece of chewing gum foil by the coil and look at the signature trace on a [unique] spectrograph O-Scope. THEN you pass a very small gold ring by the coil.....and analyze/look at the signature trace.......,,,,,,,,, there poses a fairly large (captured) signature delta. The gold ring presents a very smooth, bright trace. The chewing gum foil will generate a smeared, dull trace. BOTH metallic test subjects are of equal phase-shift conductivity; yet, gold is HIGH density, low conductivity. Foil is low density, low phase-shift conductivity. Now......... WHAT IF. What if the gold ring has a fairly large filigree top. What does THIS impose on a target signature trace. This type of gold ring will present a fairly smooth, but still bright trace. There is indeed a signature-to-hull-emitter-correlation. Captured.
Yes....... algorithms (finally!!!) can subtract out bad dirt signature/feedback; ((yet, still severely impedes EM penetration into media {dirt}.....to begin with!)). There are some unique things specific to M-IQ....... that can do 'some' unique intel with mineralized dirt.
Data collected through two (or more) channels, freq's, time-domains....... THEN run through a comparator ....... can do wonders in extrapolating lots of data..... and compartmentalizing into VERY human intelligible foray.
A specific targets conductive compositional signature ........yes. . . . can be 'signaturized' via the analyzation of different Xmit freqs resonance (and subsequent harmonics). A metallic object will resonate differently ..... with varying freq's.........AND.........can ALSO generate/emanate a different signature of hysteresis decay-rate (lapse-rate delta). Tremendous intel data can be gleaned with time-domain analysis. Soooooooo. Yes, Steve. Changing freq's on the Tarsacci ..... is to select 'capture' DIFFERENT decay rate(s). And....... also accentuates 'see-through' of other metals.......as if they don't even exist ...in the equation.

TNSS......... innovative 'passion' is what drives design engineers. Past successes & failures.....merely generates a 'database' to launch from.
When a new concept/notion presents........ EVERYTHING is kept at a 'constant'....... with ONLY one variable being changed (at a time)...... so as to capture if the single change was: additive ..... or subtractive. First....... the idea transitions from 'theorem'...........to 'proof'. Then it is implemented into a device (in this case: a metal detector). It is then bench-tested. If it graduates from the bench........ then a test-garden is the next logical sequence-of-events. After the test-garden........ then into the wild. (Real World).
Note: Controlling the variables.....sometimes...can be a insurmountable challenge. Answering your question: Minelab goes to stupendous extremes....(sometimes very costly..... both: financially and time-consuming)........... all in the attempt to create & solidify a concept----to-fruition. . . . . . . . . . . one baby step at-a-time. And when SOOOOO much 'blood' goes into a concept..... patents and NDA's are imposed to absolutely secure..... protect the 'life' (the blood) of the emanating source. So forgive me..... if I appear to be illusive-and-evasive with some of ya'll's questions. We may be VERY excited and exuberant to want to share in the happiness of a new 'discovery'; yet, only in due time.

NASA-Tom --

What you discussed/described, is VERY exciting, and very much in line with what I was trying to say in my post. I threw it out there to hopefully stimulate ideas somewhere, but I am sure that there is way more going on that what I realize (as you alluded to). Your "density" discussion would probably be the most exciting detector development I can imagine, if it could come to fruition. That would absolutely REVOLUTIONIZE park hunting -- where a veritable SEA of modern, low- to mid-conductive (but largely low-density) trash has accumulated. I have been involved in some of these "density" discussions in the past, and I would love to think that such a breakthrough may actually come, in my lifetime.

Even beyond that, though, it sounds like there is alot of creative brain power looking at ways to exploit/extract usable information from EM characteristics emanating from detected objects. And to me, that is extremely interesting, and exciting.

GREAT stuff -- and thank you for posting!

Steve

NASA-Tom Wrote:
-------------------------------------------------------
> Steve....... you've probably heard (read) for a do
> zen years......where I've preached about 'density'
> ....... and the O-Scope signatures thereof.......(
> to the point of: folks are sick of reading it!!!).
> Because we are in a new crux of electronic mindset
> ...... it may behoove me repeating.
>
> Even on a simple single freq VLF....... if you pas
> s a piece of chewing gum foil by the coil and look
> at the signature trace on a [unique] spectrograph
> O-Scope. THEN you pass a very small gold ring by t
> he coil.....and analyze/look at the signature trac
> e.......,,,,,,,,, there poses a fairly large (capt
> ured) signature delta. The gold ring presents a ve
> ry smooth, bright trace. The chewing gum foil will
> generate a smeared, dull trace. BOTH metallic test
> subjects are of equal phase-shift conductivity; ye
> t, gold is HIGH density, low conductivity. Foil is
> low density, low phase-shift conductivity. Now....
> ..... WHAT IF. What if the gold ring has a fairly
> large filigree top. What does THIS impose on a tar
> get signature trace. This type of gold ring will p
> resent a fairly smooth, but still bright trace. Th
> ere is indeed a signature-to-hull-emitter-correlat
> ion. Captured.
> Yes....... algorithms (finally!!!) can subtract ou
> t bad dirt signature/feedback; ((yet, still severe
> ly impedes EM penetration into media {dirt}.....to
> begin with!)). There are some unique things speci
> fic to M-IQ....... that can do 'some' unique intel
> with mineralized dirt.
> Data collected through two (or more) channels, fre
> q's, time-domains....... THEN run through a compar
> ator ....... can do wonders in extrapolating lots
> of data..... and compartmentalizing into VERY huma
> n intelligible foray.
> A specific targets conductive compositional signat
> ure ........yes. . . . can be 'signaturized' via t
> he analyzation of different Xmit freqs resonance (
> and subsequent harmonics). A metallic object will
> resonate differently ..... with varying freq's....
> .....AND.........can ALSO generate/emanate a diffe
> rent signature of hysteresis decay-rate (lapse-rat
> e delta). Tremendous intel data can be gleaned wit
> h time-domain analysis. Soooooooo. Yes, Steve. Cha
> nging freq's on the Tarsacci ..... is to select 'c
> apture' DIFFERENT decay rate(s). And....... also
> accentuates 'see-through' of other metals.......as
> if they don't even exist ...in the equation.
>
> TNSS......... innovative 'passion' is what drives
> design engineers. Past successes & failures.....me
> rely generates a 'database' to launch from.
> When a new concept/notion presents........ EVERYTH
> ING is kept at a 'constant'....... with ONLY one v
> ariable being changed (at a time)...... so as to c
> apture if the single change was: additive ..... or
> subtractive. First....... the idea transitions fro
> m 'theorem'...........to 'proof'. Then it is imple
> mented into a device (in this case: a metal detect
> or). It is then bench-tested. If it graduates from
> the bench........ then a test-garden is the next l
> ogical sequence-of-events. After the test-garden..
> ...... then into the wild. (Real World).
> Note: Controlling the variables.....sometimes...ca
> n be a insurmountable challenge. Answering your qu
> estion: Minelab goes to stupendous extremes....(so
> metimes very costly..... both: financially and tim
> e-consuming)........... all in the attempt to crea
> te & solidify a concept----to-fruition. . . . . .
> . . . . . one baby step at-a-time. And when SOOOOO
> much 'blood' goes into a concept..... patents and
> NDA's are imposed to absolutely secure..... protec
> t the 'life' (the blood) of the emanating source.
> So forgive me..... if I appear to be illusive-and-
> evasive with some of ya'll's questions. We may be
> VERY excited and exuberant to want to share in the
> happiness of a new 'discovery'; yet, only in due t
> ime.


What you shared Tom does shed some light for me.
Thanks.

Sometimes when you are on the "IN".....or "in-the-know".......,,,,,,,,....... you can become VERY blinded within the narrow confines of a concept/thought....,,,,,,,.......,,,,,,,,.........,,,,,,,,........and can miss an ENTIRE World of OTHER thoughts that are out there!!!........because: You can't come out of your (proverbial) box....... so as to think outside-the-box. SOOOoooooo......... what am I saying: NEVER think that YOUR thoughts/concepts are irrelevant!

Tom,

Does this mean we could possibly see "signature tracing" in the future to distinguish between two similar targets on the Equinox / Multi-IQ? ( ex. chewing gum foil and a gold ring )
Thanks - Jim


NASA-Tom Wrote:
-------------------------------------------------------
> Steve....... you've probably heard (read) for a do
> zen years......where I've preached about 'density'
> ....... and the O-Scope signatures thereof.......(
> to the point of: folks are sick of reading it!!!).
> Because we are in a new crux of electronic mindset
> ...... it may behoove me repeating.
>
> Even on a simple single freq VLF....... if you pas
> s a piece of chewing gum foil by the coil and look
> at the signature trace on a [unique] spectrograph
> O-Scope. THEN you pass a very small gold ring by t
> he coil.....and analyze/look at the signature trac
> e.......,,,,,,,,, there poses a fairly large (capt
> ured) signature delta. The gold ring presents a ve
> ry smooth, bright trace. The chewing gum foil will
> generate a smeared, dull trace. BOTH metallic test
> subjects are of equal phase-shift conductivity; ye
> t, gold is HIGH density, low conductivity. Foil is
> low density, low phase-shift conductivity. Now....
> ..... WHAT IF. What if the gold ring has a fairly
> large filigree top. What does THIS impose on a tar
> get signature trace. This type of gold ring will p
> resent a fairly smooth, but still bright trace. Th
> ere is indeed a signature-to-hull-emitter-correlat
> ion. Captured.
> Yes....... algorithms (finally!!!) can subtract ou
> t bad dirt signature/feedback; ((yet, still severe
> ly impedes EM penetration into media {dirt}.....to
> begin with!)). There are some unique things speci
> fic to M-IQ....... that can do 'some' unique intel
> with mineralized dirt.
> Data collected through two (or more) channels, fre
> q's, time-domains....... THEN run through a compar
> ator ....... can do wonders in extrapolating lots
> of data..... and compartmentalizing into VERY huma
> n intelligible foray.
> A specific targets conductive compositional signat
> ure ........yes. . . . can be 'signaturized' via t
> he analyzation of different Xmit freqs resonance (
> and subsequent harmonics). A metallic object will
> resonate differently ..... with varying freq's....
> .....AND.........can ALSO generate/emanate a diffe
> rent signature of hysteresis decay-rate (lapse-rat
> e delta). Tremendous intel data can be gleaned wit
> h time-domain analysis. Soooooooo. Yes, Steve. Cha
> nging freq's on the Tarsacci ..... is to select 'c
> apture' DIFFERENT decay rate(s). And....... also
> accentuates 'see-through' of other metals.......as
> if they don't even exist ...in the equation.
>
> TNSS......... innovative 'passion' is what drives
> design engineers. Past successes & failures.....me
> rely generates a 'database' to launch from.
> When a new concept/notion presents........ EVERYTH
> ING is kept at a 'constant'....... with ONLY one v
> ariable being changed (at a time)...... so as to c
> apture if the single change was: additive ..... or
> subtractive. First....... the idea transitions fro
> m 'theorem'...........to 'proof'. Then it is imple
> mented into a device (in this case: a metal detect
> or). It is then bench-tested. If it graduates from
> the bench........ then a test-garden is the next l
> ogical sequence-of-events. After the test-garden..
> ...... then into the wild. (Real World).
> Note: Controlling the variables.....sometimes...ca
> n be a insurmountable challenge. Answering your qu
> estion: Minelab goes to stupendous extremes....(so
> metimes very costly..... both: financially and tim
> e-consuming)........... all in the attempt to crea
> te & solidify a concept----to-fruition. . . . . .
> . . . . . one baby step at-a-time. And when SOOOOO
> much 'blood' goes into a concept..... patents and
> NDA's are imposed to absolutely secure..... protec
> t the 'life' (the blood) of the emanating source.
> So forgive me..... if I appear to be illusive-and-
> evasive with some of ya'll's questions. We may be
> VERY excited and exuberant to want to share in the
> happiness of a new 'discovery'; yet, only in due t
> ime.

Jim......... I best not answer!

But............ well worth reiterating: Minelab is far from asleep.

I completely understand (NDA) and respect your answer. Thank you - Jim


NASA-Tom Wrote:
-------------------------------------------------------
> Jim......... I best not answer!
>
> But............ well worth reiterating: Minelab is
> far from asleep.

Tom, How does the 10" CZ compare to the Equinox with 11" coil?

Kind of a unique question..........as ........ this specific thought has constantly been on the back of my mind...... for a few years. They are both SMF units. In a nutshell:

The CZ and EQX have nearly identical depth performance in the real-World.......and in a test-garden. Quarters...... Dimes........ Pennies. And the CZ has substantially less susceptibility to EMI. There has been plenty of times whereby...... the CZ takes a fairly large depth gain over the EQX..... simply due to the EQX depth/performance being inhibited by EMI. Also..... the (artificial intelligence) audible human intelligibility factor of that very discrete/distinct "high-tone" ......leaves no room for mistaking.....with a CZ. But the EQX's audio is also tremendous intel. Where there's genuinely a notable/noteworthy difference is......Nickels and low non-ferrous conductors. The EQX takes the lead...... and by a formidable/fair margin. The EQX is also the trump-card for enhanced adjacent target separation characteristics. Lest we forget: ......... in a wet-salt environment....... the CZ is (what I categorize as) "gold-dead". The EQX is quite a bit more sensitive to (low) gold conductors over the CZ platform...... unless/until you get close to the moving saltwater. On a non-performance basis (and it counts in many folks eyes) is....... the weight of the EQX is lighter than a CZ.

When I'm speaking of CZ's....... what's on my mind is....... the original Los Banos, CA Fisher Research Laboratory CZ-6, CZ-6a, CZ-5, CZ-70, CZ-3D........etc............

Tom, Didn't the CZ come out like 30 years ago? Are we still at the same depths of 30 years ago? We had no cell phones 30 years ago and now we have iPhone 12's. The world has changed in 30 years.

Kingfish Wrote:
-------------------------------------------------------
> Tom, Didn't the CZ come out like 30 years ago? Are
> we still at the same depths of 30 years ago? We ha
> d no cell phones 30 years ago and now we have iPho
> ne 12's. The world has changed in 30 years.

[www.detectorprospector.com]

That is correct. CZ platform came out over 30-years ago. In fact.......prototypes (nearly fully certified)......were on the streets in 1990. Dave Johnson takes FULL invention credit for the CZ legacy. ((( I merely REinvented the wheel..... with the CZ-70 & CZ-3D ))). Yes, CZ's are still produced today. CZ-3D & CZ-21. No.........we have not gained any more depth in 30-years (3-Decades). But....... I must premise with the following:

In the 1970's........ the average coil size was 6".
In the 1990's........ the average coil size was 8".
In the 2010's........ the average coil size was 11".

Which/then...... segue's into: "WHAT IF". What if .....(say)...... a Equinox of today...were to sport a 1990's coil size....of 8". What would it's depth be? ---------------It would be the same depth as a CZ that was sporting a 8" coil. The stock 11" coil that comes with the Equinox will indeed go deeper than a 8" coil. Sooooooo.............what have we gained? A 11" DD coil equipped EQX presents about the same adjacent target separation characteristics as the 8" coil CZ platform. BUT...... at the 11" coil-size capable depths. This may not sound like much...... but..... none-the-less....... it is indeed a improvement. Microelectronics are faster (OS clock-speed)...... which allows for this 'realized' enhanced target separation.
The ID capabilities of the 30-year old CZ....... were stunning (and still are).......and: to depth! Today.......the ID's are spanned out to 40 or 50 or 99 (on some brands/units)....... and the ID's are ALSO very good. Even at depth. Like the EQX.
CZ is SMF. EQX is also SMF. Both units have about the same 'bad dirt' handling/punching abilities. Not much 'gain' in performance from 30-years ago.

(((More than))) just a gut feeling: Tarsacci (Dimitar & crew)........ ---right now--- is our only hope for busting through BOTH "bad dirt handling".....and..... 30 ++ year depth incarcerated plateau. Minelab is runner-up for performing aforementioned task. Especially if GPX can progress-forward-advance to a Revolutionary GEN-2.

We gotta depart from the VLF/SMF sandbox.

Tom, Thanks once again for your answers. I always enjoy reading your responses and the stuff that's on this forum. One more question that has been on my mind. What things do you NOT like about the Tarsacci? What would you like to see improved?

That's kinda disappointing that the only evolution we have seen in 30 years is the speed of electronics. I almost feel obligated to invest in a Tarsacci just to have hope for the future of the hobby. I personally have been impressed with target separation since the Dues and Equinox. I thought we were on the verge of a technology breakthrough. Increased depth is worthless to me without target ID. I have no interest in digging 15 inches for iron. Not in dirt anyways.

Kingfish.......... I must answer your question.........from the opposite direction.
I have been absolutely spoiled with extremely accurate ID. It started 30-years ago with a CZ-6. For instance: A Indian Head penny (without much corrosion) will ID at the very bottom hair-splitting line of the Zinc Cent ID. If the Indian Head penny was 1" deep.......... or 10" deep........ the CZ-6 would ID it as a "Zinc Cent". This kind of (at depth) ID accuracy.....always stunned me.....(for physics/electrical-engineering feat phenomena).
Fast-forward 30 years. If a 1" deep "V" Nickel ID's as VDI '12' on the EQX........................... it ALSO ID's as '12' when 10" deep. Even with close-proximity small amounts of contaminants near the Nickel.......the EQX will still 'lock-on' to strongest signal-strength......and NOT "average" the trash into the equation........algebraically/algorithmically.
I am SPOILED....with this kind of accuracy (and benchmark). Although these units are not perfect........ I use this/these as my 'bench'....... and call it (reference it as = ) 100%.
Sooo......... where am I going with this. = The Tarsacci ID accuracy/ABILITIES....... are around 70% (of above/said/stated) results. This is "more than enough"; yet, I am spoiled by the 100% 'bench' ......as a base-reference. But......... now I must premise with this: The Tarsacci is not VLF-SMF. It is a totally different O.S. (Operating System)........ based off of (predominantly) Time-Domain. ---- Truly: Next-Gen.........albeit (mildly crude).
Here in Florida..... I have (now) had several experiences whereby...... the CZ & EQX would stop ID'ing coin-sized targets that were beyond 7" deep. This is 3-bar (Fe3O4) dirt. The Tarsacci ALSO suffered in this dirt..... but to a lessor extent. It would properly ID targets down to only 10" deep. (This was in 6.4Khz. I did not experiment with the other 3 available Freq's).
Soooo......... that would be my first gripe about the Tarsacci. 70%. I would like to see this ID accuracy improved to 80% - 85% range.

My 2nd concern with the Tarsacci would be: EMI. It mitigates EMI at a 'above-average' rate. Not bad. Yet......... ----BUT...... when you incur EMI.,.,.,.,.,., that's it. There is nothing you can do about it. You can (worst-enemy....... the LAST thing you want to do)...... drop Sens and increase Thresh....... to mitigate EMI. You can also change freq's.....to possibly mitigate EMI; yet, this may put you in a position where you have to run a Freq that is the exact opposite of intended target conductivity.
I'm not sure how many folks are running into EMI issues with the MDT.......and I probably should ask this question (on the MDT thread)....... but EMI does occasionally happen to the MDT.

I think the control-head could be placed about 1" forward on the shaft. I have a hard time yanking my thumb up (and onto) the faceplate to access the pinpoint (or any other) button. (This is a mild concern of mine; as...... I place nearly all of my focus on performance...... and not ergonomics).

It may sound like I am really disliking the MDT. That is FAR from true! I am having stupendous performance inland....... in very mild dirt........and especially: medium mineralization!
What's crazy is........... the EQX will far out-trump the MDT in my test-garden. But...... in the real-World (dirt with a multiplicity of variable contaminants.......ie....minerals & small metallic particulates) the tables can (very easily) turn! I am witnessing this time-and-time again.

I'm just returning from the field...... after a psychotic/psychosis testing campaign with EQX. Nutshell:
It would take 8 - 8-1/2 minutes to MANUALLY find the best Noise Cancel Channel. Then I would/could hunt for about 2 minutes.
Local/ambient EMI atmospheric conditions would change.......... requiring a new Noise Cancel Channel.
It would take another 8 to 8-1/2 minutes to manually find another 'best' Noise Cancel Channel. Then I could hunt for about another 2 minutes.
Then another 8 to 8-1/2 minutes to find a new 'best' Noise Cancel Channel.
Psychotically ....... I performed this methodology for nearly 6 hours.

Summation: The (merely) 2-minutes of hunt time....between finding best Noise Cancel Channel........ REALLY 'produced'. . . . . . . after several sessions of 2-minute hunt times.

EMI is a KILLER.

Tell the manufacturers we need this done automatically while we hunt. I tend not to noise cancel at all because it is only one frame in a long movie.



Edited 1 time(s). Last edit at 10/10/2021 12:43AM by goodmore.

An UNBELIEVABLE amount of patience/persistence.

When you say "produced," that site must REALLY have produced, for those brief two-minute intervals.

Question -- how did you know when the machine was no longer performing optimally (after two minutes); presumably a sudden increase in the audible EMI?

Steve

NASA-Tom Wrote:
-------------------------------------------------------
> I'm just returning from the field...... after a ps
> ychotic/psychosis testing campaign with EQX. Nutsh
> ell:
> It would take 8 - 8-1/2 minutes to MANUALLY find t
> he best Noise Cancel Channel. Then I would/could h
> unt for about 2 minutes.
> Local/ambient EMI atmospheric conditions would cha
> nge.......... requiring a new Noise Cancel Channel
> .
> It would take another 8 to 8-1/2 minutes to manual
> ly find another 'best' Noise Cancel Channel. Then
> I could hunt for about another 2 minutes.
> Then another 8 to 8-1/2 minutes to find a new 'bes
> t' Noise Cancel Channel.
> Psychotically ....... I performed this methodology
> for nearly 6 hours.
>
> Summation: The (merely) 2-minutes of hunt time....
> between finding best Noise Cancel Channel........
> REALLY 'produced'. . . . . . . after several sessi
> ons of 2-minute hunt times.
>
> EMI is a KILLER.

Steve................... logical question. I merely WISHED it were that easy/simple/straight-forward for you to know that you are on the wrong EMI channel. Yes.............. there are times when you would 'audibly' know that EMI conditions have changed,.,.,., simply by your audio level suddenly becoming 'chatty'. BUT ......... there were plenty of times whereby......you had nearly NO audio 'clue' that something had changed. Carrying a clad dime in my pocket....... to verify a quick air-test performance was up-to-par.....,,,,,,,........,,,,,,,,......... was never 100% telling. Yes, it exposed a few of the silent EMI inhibiting incursions; yet, far from a tell-all.
This may (((IS))) crazy........ but helped me out the most....was: I had already hunted this dirt MANY times before. NOTHING 'should' be found. When I would find a target (my prereq requirements were: anything that was approx 3-Cent Nickel conductivity ...and above.......,,,,,,,,,I would dig .,.,.,.,.,.,.,.,., ---- as they should have already been found/dug/recovered ....from any/all previous 'sanitizing' hunts). ------- So now:
I would find a target of interest. I would NOT dig/recover it. I would 'mark' the spot. Then........ I would move on to the next target. IF IF IF I found "the next target"....... I would leave it (and mark its exact pinpoint location).....and go back to the previous target.... and dig/recover it. If the detector no longer could see/detect this previous target.,.,.,.,.,.,.,.,.,., I would know something with EMI has occurred .,.,.,.,., and would need 'correcting' in order to find/hear/detect this already-marked (detected) target.
If I could STILL detect the previous target....... I would recover it. , . , . , . , . , and leave the newest target 'unrecovered'.......until I found yet a (even newer) target.
And THIS is where I encountered the most err. (Due to larger time-lapse). I would no longer be finding any newer targets. Suddenly the dirt stopped producing. (I would know: something was wrong). Thank goodness I still had one (the newest one) unrecovered "marked" target. I would then 'test' the detector on this undug target that I JUST found (about a minute or two ago)........ and....sure enough.... the detector would no longer detect it.,.,.,.,.,., regardless of coil velocity, approach angle, coil height.....etc...........
Something "changed"!!! A new EMI channel is required!!!! UNKNOWINGLY!!!! Silently!!!!!
The BAD thing was: There were plenty of times whereby a ""new best Noise Cancel channel"" would NOT even detect the "just found: one minute ago" marked spot/target. ----{{{{ I shall spare you some of my exercise-in-futility...of all the ridiculous protocol....... to re-ascertain! (Noise Cancel retry .... every 2-3 minutes..... until resolve!.....was primary protocol!) }}}}
This entire day was nearly an exercise-in-futility....throughout!!!
But....... this should give you the gist.

I almost never noise cancel once I do the initial noise cancel at the site. Unless the machine starts to get chatty. I will definitively have to pay more attention to this in the future. That would explain some experiences in the past where I marked targets and left them for a few days to a week. Only to come back to do some detector comparisons on them to find they had essentially disappeared to every detector but my GPX.

This all very interesting but also disconcerting. I am glad that Tom D has made the seriousness of this issue as well known as possible. Hopefully the manufacturers and engineers are aggressively addressing the problem. Conquering it would be a true "Breakthrough".

Chris

I've had days like this also. Example, my test garden... I run my detectors over the buried targets often. I live in a community. Some days no matter what I try the equinox will not hit a few of the targets, other days it hit them all. My deus using black x35 coils some days won't hit some of the targets, other days its fine. Unless I use the white coils then the deus always hit the targets in my garden. Funny thing to, the simplex always hits the targets.

The Deus is a fine detector. I owned a few through the years. I was astounded by it' s performance many times. That being said it is also the detector which I had the most problems with when it comes to the issue of EMI. The wireless coil in my opinion was a gimmick. I really never saw the point. I have never been that inconvenienced by a coil wire. I always had the controller mounted for VDI verification. To me it was a vulnerable point for EMI to enter and degrade the signal. I mentioned this before on this forum. But since that post I often wondered about the wireless signal to the headphones on detectors. I assume that it is not relevant because the target signal from the coil has already been processed and the signal to the headphones is just a report. I remember the old days of hunting beaches with my buddies. The days of the Sovereign and Excals. We couldn't get near each other because the detectors would go unstable and become useless. I often wonder how many deep targets I passed by because of another detector near me was just inside my zone for EMI corruption. Yeah detectorists creating their own EMI. Go figure.



Edited 2 time(s). Last edit at 10/12/2021 11:43AM by goodmore.

I agree Tom..... couple of things that have made the greatest improve in my hunting have been larger coils and better headphones. When the explorer went from ten inch coil to the 11 you noticed it. Also.... making a machine usable for the new guys right out of the box is great...... but at what cost to the experienced hunter?

NASA-Tom,

Wow, what an amazing story. Truly amazing; mind-blowing, actually. While extremely tedious, your "plan of attack" was ingenious, and your experience educational for us all. More importantly, though, is that YOU experienced it...given that you are in a position and have the capability of finding ways to begin to solve this issue.

Just an incredible story; thanks for taking the time to share in detail. It certainly has stimulated thinking/pondering on my part -- and learning something new -- to me -- makes for a successful day!

Steve