Etrac users

Don't take the following statement in a negative way. I found the book of most value in reducing my learning curve of a new machine.

Not sure if Andy's statement is 100% true but here goes.
From his book, The Minelab Explorer & E-Trac Handbook.

page: 25
Andy states the sensitivity option is used to set the power output of the Etrac.
Now it was my understanding that about all machines have a constant output.
I also know and understand that both the Explorer and Etrac have many hidden or maybe I should say undisclosed information about some if their features.
Example: noise cancel, sensitivity setting channels just to mention a few.

Now I'm not going to ask questions that can not be answered at this present time.


I welcome comments.

The option he is speaking of is semi-auto or manual auto on the Explorer. If you want the detector to pick the best sens for the ground your detecting over, (less falsing/noise more stability), choose semi-auto. Semi-auto, not full, because you pick the sens according to the conditions and desires and the detector will try to live up to your sens number if ground conditions suffice.
Manual sens, you pick the sens: higher number = more depth and smaller targets can be detected plus possibly more falsing/noise, the detector makes no changes in sens.

Oh now I see why you question Andy's first sentence on page 25. Because the understanding is that the output on most (if not all detectors) stays constant, and by increasing or decreasing the sens, (we know from reading) that it's the recieving area that gets changed higher or lower not the output. I just realized what you were getting at but I'm not going to delete the paragraph as it may help someone.

I happened to be rereading the Etrac chapter right now. For those that do not have the book here is exactly how it reads.
"The Sensitivity option is used to set the power output of the detector which determines how deep the detector will be able to locate targets and how small a target can be detected."

My understanding is one that has not used a previous explorer would catch on quicker to it abilities and workings so must be quite a difference in the old and new..Read this from several competent individuals so must have some validity...

Don't some detectors have the ability to adjust the output into the ground ? I seem to think on my DFX, that the AC and DC sensitivities regulate output while the pre-amp gain regulates input ( receive ) or vice versa...can't remember which one does what !!

Yes...no ?

I'm like you I thought it was a constant output and variable receive. But that is not what Andy is saying there,,,, hummmm

Straighten us out...Tom, Andy?

Most people understand the Sens as output power but it is not.

On all FBS the output power is the same regardless of sens setting, sens setting adjusts sensitivity towards the receive channel and therby boosts all signals.

Signals from EMI, Ground, Targets.

What regulates Output power is law and battery drain. The V3 has a boost mode that increase the Transmit signal but it drains the power dramatically..

frnifo Wrote:
-------------------------------------------------------
> Most people understand the Sens as output power
> but it is not.
>
> On all FBS the output power is the same regardless
> of sens setting, sens setting adjusts sensitivity
> towards the receive channel and therby boosts all
> signals.
>
> Signals from EMI, Ground, Targets.
>
> What regulates Output power is law and battery
> drain. The V3 has a boost mode that increase the
> Transmit signal but it drains the power
> dramatically..

And for anyone curious, the depth increase is only about 1". I have tested the Tx boost on my V3i and it does very noticeably improve deeper signals but drains the battery up to 50% or so quicker. I forget the number but I think the transmit power is increased by 3! (Not a very efficient way of getting an extra 1") but...
The nice thing is that if EMI is very bad (and minerals low) you can run the Tx Boost and overpower the EMI (I hear) so you can hear the signals.

EMS

I have heard from a trusted source that after he having a very long and technical discussion with the bench tech at Minelab repair that the bench tech would never hunt outside of Auto +3 (or less if needed based on conditions). He would never use the E-Trac in manual. He claims there is something that the machine is doing when in auto that makes it superior to manual. I can't offer any opinion as I only detect in auto +3.

I do not have the confidential data IRT the Explorer/E-Trac........ yet, I would still suspect the Xmit power is a 'constant'.

barryny Wrote:
-------------------------------------------------------
> I have heard from a trusted source that after he
> having a very long and technical discussion with
> the bench tech at Minelab repair that the bench
> tech would never hunt outside of Auto +3 (or less
> if needed based on conditions). He would never
> use the E-Trac in manual. He claims there is
> something that the machine is doing when in auto
> that makes it superior to manual. I can't offer
> any opinion as I only detect in auto +3.
it bothers me that ML has so many secrets,,,,,, this is new one for me, the noise cancel mystery is still not clear to me. You think they would want you to know as much as possible so you would find as much as you can and brag about their machines,,,,,

earthmansurfer Wrote:
-------------------------------------------------------
> And for anyone curious, the depth increase is only
> about 1". I have tested the Tx boost on my V3i and
> it does very noticeably improve deeper signals but
> drains the battery up to 50% or so quicker. I
> forget the number but I think the transmit power
> is increased by 3! (Not a very efficient way of
> getting an extra 1") but...
> The nice thing is that if EMI is very bad (and
> minerals low) you can run the Tx Boost and
> overpower the EMI (I hear) so you can hear the
> signals.
>
> EMS

Very accurate description all of it. I also use the TX Boost when in EMI surroundings and the boost gives additional depth when you have to turn RX gain and RX sens AC and DC down. And it seems to me that in terrible EMI situations you get more then 1" additional depth out of it. Maybe because you are not running high Gain or sens levels to minimize EMI.

It is nice to know that increased output power from your own machine does not give the same machine interference, but your detecting pal will be affected if he is from before.

in Air and in my testbed it is like you say. 1 "



Edited 1 time(s). Last edit at 10/30/2011 05:39PM by frnifo.

wurthless --

I couldn't agree more. Even if they don't want to give away the "secrets," I wish ML would let us know more about how to use the settings and when. Is it better to choose a specific noise cancel channel at times? WHY is auto +3 on the E-Trac better? How would that translate over to an Explorer (where you can run "auto," or manual, but don't have an "auto +3" option?) It's frustrating, in that it makes each ML user individually have to "re-invent the wheel" in terms of figuring out what each adjustment does to performance, by using each adjustment over long periods of time, over many targets, to understand the effects.

Steve

Thank you Steve. It is as you say, and really a pain. All you hear on the forums is, "I think this is how it works".

Mineralization content dictates. Down here in Florida........ 'manual' Sens on the Minelab's is where max performance can be ascertained in nearly all cases.... for turf hunting.

I'm always on +3

One secret is how were able to get an acepted target to come though a null "rejected target". Something other explorer machines have a hard time doing. Throwing masking and silent masking out the window to a degree.

EZrider Wrote:
-------------------------------------------------------
> I'm always on +3
>
> One secret is how were able to get an acepted
> target to come though a null "rejected target".
> Something other explorer machines have a hard time
> doing. Throwing masking and silent masking out the
> window to a degree.
you touched yet another mystery,,,, the minelab tech says while in null no other targets can be detected,,, but then they state that "trash high" will pull an accepted target thru and over a rejected target.. I'm a little dense sometimes but it seems like they are saying two opposite things here,,,, will it or won't it ? ( I say it does cuz I've pulled coins out of holes with nails in there,,, but why are we told to slow down to a crawl to allow the null to pass)

Guys --

I have thought and thought and thought about this question that wurthless asks, and that EZrider is discussing, related to nulls of threshold on a Minelab FBS unit, and "breaking the null" and masking and partial masking and how this all relates. Here is what I've come up with; please, NASA-Tom, correct anything I am wrong about.

As we all know, due to the nature of iron it has the capacity to "overwhelm" nearby targets. Even shallow rust flakes can kill your detector's ability to "see" a good target beneath, as NASA-Tom has stated. We all know this -- this is the "masking" and "silent-masking" issue, and while some detectors and setups can "unmask" better than others, NO detector that works based on electromagnetics (our current detectors) can completely overcome masking -- due simply to the physics.

When running "iron mask" (Explorer) or "quick mask" (E-Trac) -- and setting the mask to just reject iron, then any "null" of the threshold is suggesting that the machine is detecting iron. Detect a coin, hear a tone. Detect iron, hear a "blank" or a "null" in the threshold. Easy enough. A null is just the "audio effect" of iron detection, just as a "high tone" is the "audio effect" of a high conductivity target detection. Further though, the null ALSO means, obviously -- but in a more "indirect" way, that the POTENTIAL exists in that specific spot/coil location, for IRON MASKING. Simple enough; iron present ALWAYS means possible masking issues. To me, I think of the null as both an "iron is present" indicator, and also an alert that in this spot of ground, "iron masking" is possible. So, WILL the detector see a nearby "good" target? The answer to this question is also the answer to the question of "is the target "masked" or not, to my machine/setup."

To elaborate, consider a nail, sitting a couple of inches above a coin -- a coin which otherwise is at shallow-enough depth to be easily detected and ID'd. The nail sitting above the coin is likely to mask, partially or completely, the coin. IF the coin is "completely masked" with respect to the machine/coil being used and the way the machine is set up, THEN, the "null" will NOT be "broken" -- i.e., the machine cannot "see" the target due to being overwhelmed by the iron. On the other hand, if the nail is in such a configuration and position relative to the coin, that the machine/coil/setup CAN "see" the coin, then by definition the coin is NOT fully masked (with respect to this machine/setup), and thus the machine will SEE it, and thus the threshold "null" will be "broken." In this case, you'll obviously hear the target reported to you in some way -- either a degraded or "iffy" signal (meaning the coin is "partially masked" to that machine/setup), or a good, clean coin signal (meaning the coin is NOT masked to that machine/setup.)

What I'm saying is, certain configurations/positions/locations of iron relative to a good target WILL mask the good target, some will do so PARTIALLY, and some will not do so at all. It depends upon the positioning of the coin and the iron, AND the machine/coil/setup you are using. Bottom line, though, is that with an Explorer or E-Trac, the answer to the question of "will the null of the threshold due to iron, be "broken" -- i.e. will the machine "see" a good target while in a null" is the wrong question. Whether the good target is seen, is NOT a function of the null itself; to me, the null is an INDICATOR of iron present, and the corresponding potential for masking. The more correct question, in my opinion, is "will my machine/coil/setup be able to "see," i.e. "unmask" this particular coin/iron juxtaposition -- because if it CAN, my threshold null will be "broken" and I'll get an audio report; if it CANNOT, then my threshold null will remain "unbroken." "

To state slightly differently, the issue to me is not "can the E-Trac detect a coin through a null;" the more correct question is "can the E-Trac/coil/settings I'm using unmask this particular coin/iron situation sufficiently to "see" the coin at all" (and if so, then YES the threshold null will be broken and you'll get an audio report).

I hope I explained this well enough that it makes sense, and I think I have represented things correctly. The only other thing I'll say is, I will guess that "trash high" on the E-Trac simply is some "boost" in "recovery speed," sort of like "fast=on" on the Explorer -- such that you might have a better chance to separate the coin from the iron, and thus bring that coin "out of fully masked" status, and into "partially masked" status -- allowing the machine to pick it up and report it.

So, my take is that when the Minelab tech says "while in a null no target can be detected," this is basically true -- but is mixing up "cause" and "effect." The NULL is not the cause of the target not being detected, the IRON is the cause. The NULL is the EFFECT of the iron being detected (that is masking the good target). I think the more correct statement from the Minelab tech would have been "while in null, the machine is seeing iron, and therefore any nearby good target is probably being masked by the iron, and thus the machine will likely not "detect" this target." Likewise, on the statement that Minelab makes to say "with TRASH on HIGH the machine will pull an accepted target through and over a rejected target," I think the more correct statement would be "with TRASH on HIGH, we at Minelab think the machine WILL BE SLIGHTLY MORE LIKELY TO BE ABLE TO pull an accepted target through and over a rejected target." Obviously, the "will" is some marketing hype, as that cannot be stated categorically!

Thoughts?

Steve



Edited 5 time(s). Last edit at 11/01/2011 06:55PM by steveg.

I just discovered this a few days ago and was amazed to say the least.The dime under the cap touching cap or a 1/4" beneath will give a nice solid high tone up to several inches in air test.Remove dime and Bud Light cap gives no response.I tried this test with a 12x13 and 8x6 coil with near same results.Not sure if pro coil will do same.
I have always been told that no machine can see through iron/steel but my results would show different.Perhaps folke with E-Tracs and other machines could try this test and report results......



Edited 1 time(s). Last edit at 11/01/2011 05:59PM by silverhound.

Thanks steveg, very good explaination.

well wrote steveg, i totally agree with every word wrote in regards to the etrac,and have never read a better summery of how the detector functions

You know how were told not to discrim so we can hear a good target next to a bad one ? I think what ML did with some of the ETracs filtering is alow the machine to recive the disced signal but not let the audio to come though. Where as some other machines "even ML" block out the signal all together. I wonder if this is because it a threshold type of machine and not a silent search type.

steveg.... that is very exacting. I want to add one more additional comment.

Seems to me...... folks are biased to believe the Minelab E-Trac/Explorer will 'unmask' a greater amount of targets (better-than/over/above)........ vs ......... other units. In other words.......... the Minelab will have a higher percentage of 'good targets found' due to some form of additional 'unmasking' enhancement/attribute.

I live/hunt/breathe/attempt-to-succeed in iron infested sites. I have no choice. The older the site...... the less the aluminum trash. (And the higher the iron trash content). Thus far...... the laws of physics have dictated:

* iron will inhibit/distort/cripple the electromagnetic (EM) energy eminating from any coil of any detector........ regardless of detector brand.
* Transmit frequency dictates if the unit is hyper-sensitive to iron...... or non-resonant to iron.
* Coil EM footprint will alter resultant as to 'how much' of the EM energy will be attenuated by masking culprit.
* Clock-speed of detectors microprocessor plays a large role as to 'reset' the (null) performance 'between targets'.
* Phase-angle wrap-around also dictates 'perceived' iron see-thru; yet, elevates 'falsing' percentage/ratio.

The Minelab E's..... operate at a lower freq(s) ..... subsequently presenting a more 'iron dead' effect. There are plenty of other detectors that operate at lower freqs..... with same end resultant. . . . . . that being: less resonant to iron..... more resonant (deeper) to silver. The E's are very good with deep high-conductive silver.

If the Minelabs were better in iron..... I would immediately switch over to a Minelab......... as............. I have more years behind me..... than I have ahead of me! Youth is gone; time is of essence.

"Perceived" vs "Reality" matter!

Question... if the E-trac nulls out iron, does it ever give false 'good' tones like a CZ will on some larger or odd shaped iron targets? I would love it if my CZ3D would null out on iron and not give false high tones. The lower frequency of the E-trac may help some in this area, but I wonder if there is some way of modding the CZ3D to null on iron. Discriminating out the iron doesn't help. As a matter of fact, it makes things worse because you will still hear the "false" highs from some iron targets and think it's a good target trying to be detected.

Anyone know if this is possible or has the 3d being set up to to forever give false highs on much of the iron it detects? Don't get me wrong. I love my 3d, but it would sure be nice if it would either not give false highs on iron, or null out like the E-trac was mentioned to do here.

The architect of the CZ does not lend itself to be modified ... to give a 'null' on iron. Also........... there's not much that can be done to help rid the high-tone falses on the CZ platform. And............ if you 'null' the iron......... you would then ONLY hear the high-tone falses; subsequently.... chase a lot of 'ghost' signals.

Well written Steve.
Without going into to much detail, as Im short on time, I do NOT agree with the MineLab techs statement regarding the Etrac and Explorer not being able to hear tones through nulls. I have talked with Ralph DeGraw (SunRay) at lenght for some time now and just recently about just this topic. Ralph has been using the Explorers since they came out and the Etrac and has more time and experience than anyone I know on those machines. Ralph relayed a experience he had of hunting in a field that most people almost always give up on because of the excessive nulling. He took his time and went slow and ended up finding some Barber silver UNDER all that nulling. I found it hard to believe myself but I have experienced myself where if you go slow enough and have the right settings you will get the tones through a null. Now as Steve put it, it all depends how the target is situated. If the coin is right under that iron and the iron is big enough...your probably not gonna hear through the null, and if it is off center from the iron theres a chance that you will.
I just got down comparing both my Etrac and 75 LTD over the weekend on a old farm house site I've been hunting for 2yrs now. The whole property is just one big null,,,I dont think the original people ever threw anything out, they probably just buried it. I used 5" coils on both machines and even with the 5" coil on the Etrac theres still alot of nulling, but I still able to do ALOT better than when I had the bigger procoil on. However...it still does not compare to the F75LTD, the speed of that thing in between targets is incredible although its sooo noisy it tends to wear you out faster. I had experimented in a 6x8ft area first with the Etrac and then with the LTD both with 5" coils and I was amazed how many ferrous targets ( clad, bullets, casings, ect) the Etrac missed around all that iron even with the 5 coil.



Edited 2 time(s). Last edit at 11/02/2011 11:06AM by Aaron.

It seems that Aaron and NASA-Tom both said the same thing -- that the Minelab E's, while good, are NOT quite as good in iron as the faster Fishers can be (though I agree with Aaron that the Fishers try to "wear you out" audibly). I also agree with NASA-Tom that people seem to think there is something "mythical" about the "unmasking" ability of the Minelabs...I feel they do a good job, but "mythical?" That's not my experience. They excel at finding silver, for sure, but I believe that NASA-Tom explained the reasons why that is the case, and it's not that they "unmask" in some "mythically superior" way. Sure, like Aaron said, you can surprise yourself by moving real slow with a small coil on a Minelab "E," finding stuff that was hidden in the iron (I have been surprised at times)...but are they BETTER in that regard than one of the fast Fishers? I personally haven't felt that way, with my Explorer -- after hunting AND test garden testing with the Explorer, and with my Gold Bug Pro and F70. Again, as NASA-Tom said, good, but not "better".

BUT -- I would like to ask, NASA-Tom, if you might explain this quote you made a bit more...

Quote

Phase-angle wrap-around also dictates 'perceived' iron see-thru; yet, elevates 'falsing' percentage/ratio.

I think you may have said the Minelab "E's" can do this "phase angle wrap-around" thing (in another thread)? What does this mean? I find this interesting but don't understand...and I do notice alot of falsing on iron -- ESPECIALLY when running high manual sensitivity...

OH -- to answer your question connortn -- YES, the Minelab FBS machines DO "high tone false" on iron! I think maybe the E-Trac does it less, not sure as I don't use one, but that's my impression in the few times I've swung it; but I KNOW the Explorers do; like I said above, ESPECIALLY when running them "hot." The ONLY good thing is, SINCE you have a threshold null, it alerts you that iron is there, so the "falses" amongst the sustained nulls allow you some clue as to what's going on. On a machine where disc'ed out iron is SILENT, then I agree with you, it is much tougher and, as NASA-Tom says, you end up chasing alot of "ghost" signals.

Steve



Edited 1 time(s). Last edit at 11/02/2011 02:57PM by steveg.

Aaron, but did it miss silver? It seems that silver stands out to most of us coin hunters and when you look on the E-Trac forums it sure seems to find a lot of silver with iron in the whole or maybe only a small % is with iron? I believe your tests though. Is it partly the sheer numbers of E-Tracs, good out of the box depth, relative ease of use, lower freqs, etc. that are responsible for the silver totals? I had a T2 for years and didn't find much silver with it, but when I got the Omega I started to find a lot more, then the V3i which is on par with the Omega but slightly better overall (esp on hammereds).

As most of you know I have a White's V3i. I don't mean to jump in here, but I can run some interesting tests as this machine is very flexible. I can run it in so many ways it ain't funny (really, it can be a headache. ehehe) I'm in Europe (Germany) and the amount of rusted iron in the ground is pretty much beyond what most guys in the U.S. experience. So I can do some interesting testing. But for the most part, most of the coins I find are in iron and I hunt in 3 freq.

Anyway, I'd be curious to hear your suggestions as how I should run it in iron for silver. I can run it in 2.5kHz, 7.5, 22.5 or in 3 frequency (2.5, 7.5, 22.5) w/ correlate and a variety of recovery speeds. For Silver I'd run it in 2.5 or 3 freq, maybe 7.5. I have the 5" excellerator, 6X10 and 10" stock (all are DD coils) as well as a 9.5" concentric. Generally I run the 6X10 coil in 3 frequencies w/ correlate, with a lot of sensitivity (but not noisy), the lowest (deepest) filters, and a medium level recovery delay (as that actually works ok in correlate). My ground is not mineralized, but very high in iron mineralization content (if that makes sense). I also set the iron tone to zero, which free's the discrimination circuits. I run a threshold that "nulls" over iron, but it isn't a disc null, it's just a zero tone on the iron - less penalty I believe.

I wonder if the E-Trac's are running a form of correlate as well.

Thx,
EMS

Just by virtue of 'going extra slow' in a hunted-out field.... with the Minelab.... THIS ALONE (going extra slow) changes the entire equation...... and your end-resultant is GOING to be: 'finding more stuff'. Going extra slow with ANY unit will create a better resultant...... especially in littered areas.

Yes..... the T2 and F-series units will 'wear you out' with SO much audio chatter. But....... that's because they detect/see/report several times more targets per any given sweep. Much more targets for the operator to choose from. If you ever have the psyche/mind-set/stamina to dig a few of those audibly fatiguing 'micro-chatters'........ you will learn they are real targets...... small as they may be. The T & F series units will take many more 'snapshots' for every inch of coil sweep/motion then any other unit currently available on the market today.... due to rapid microprocessor clock-speed. Do they 'false' a lot? Yes... if there is EMI present. If there is minimal EMI present....... do they 'false' on actual in-ground targets? This is a difficult-to-answer rationale/justification ...... due to geophysics principle. When T2/F70/F75 INITIALLY approach into a target (and the coil is NOT YET over the top-dead-center of the target)....... the multiple snap-shots (electromagnetic samples) taken are not quite representative of the 'whole/full' target; subsequently, the microprocessor is going to report ONLY THE PORTION of the target that it has sampled.... thus far..... probably not representative of the aggregate conductivity of the 'whole' target. And to 'sample' (snap-shot) the tip of a nail (before the coil is passed over the rest of the target)...... can certainly present interesting audio resultant(s). By virtue of slowing down the microprocessor/clock-speed....... the targets will audibly 'smooth out'......... at the cost of missing plenty of targets in between. (((Failed adjacent-target separation))). Minelab Explorer Audio-1, Audio-2 and Audio-3 will do exactly this. Audio-1 is the fastest clock-speed.... the most audibly fatiguing..... the 'hill-billy jug-band flute......... and 'music' to many 'tuned' ears.

Phase-angle wrap-around: Target ID is created by phase angle. There are multiple "signature" components of iron. A couple of the (less dominant) iron electromagnetic signature components... bias towards the high-conductor phase angle ID. (((So far.... no ID problems))). If the target is a nail with a fairly sharp tip.... the 'less dominant' phase-angle ID signature becomes a bit more 'dominant'. Problems 'might' start to annunciate. Now........ if the nail is bent.... AND.... has a sharp tip/heel........... the less dominant (minor component) of iron becomes major/dominating........... with subsequent false ID. The sharp tip of the nail is one problem. The bent 'arc' of the nail is another problem. If the nail is bent beyond 90-Deg.... the two (approaching parallel) portions of the nail provide yet a third phase-angle overlapping problem. The dominant overlapping phase-angle signature that ensues.... will generate "end resultant" right smack into 'high-conductor' phase-angle ID. This is ONE of the justifications/definitions of 'wrap-around'. If the design engineer chooses to 'push' the unmasking abilities/capabilities of his electronic architect/platform..... it is common to boost the 'less dominant' iron signature/phase-angle.....to a bit more aggressive 'dominant' status.... so as to encroach the non-ferrous threshold phase-angle baseline. Unmasking is enhanced..... at the cost of 'more falsing'. Bruce Candy was moderately conservative with the Explorer's iron wrap-around. A high conductor (say a silver dime) in very close proximity to a low conductor nail...... can easily 'enhance' the "less dominant" iron phase-angle signature.... and wrap it around into the high conductor angle...... with subsequent 'coin-ID' audio report. Yes.... there are times that we have dug a high conductor coin out of a hole.... and a nail or two.... came out of the same excavated hole. And...... there are times when we have dug a 'coin ID'......... only to find the 'tip' of a nail barely sticking out from the side of the hole.
..... In short: When the phase-angle of iron is distorted.... and the angle wraps-around into the high-conductor phase angle ID bandwidth/range..... you will acquire a high-tone 'false'.