multis vs.( v.l.f.) single frequency

Is the new T2 15" coil a concentric?

Ozzie....obviously it depends on who is using the SE or E as to the depth. Thats what i was saying ... once learned i find the SE just as deep and the E didnt seem to have an advantage in finds. Id say those graphs show an interesting reason some of us havent switched. But thats normal.... i know a lot of people who wouldnt switch from the Exp II to the SE. That changed some after the Pro coil was introduced because the standard coil was just BETTER on the Exp II. The only problem i see with the graphs are .... thats in a perfect world.... go deeper those change a bit. Tom if you are watching..... what do you think of the graphs?

Dew

And those graphs don't even depict how easy it is to learn the cursor bounce as opposed to the associated 4 - 5 numbers on a linear machine. Also, the delta pitch give you a lot of information without looking at that screen. I found my F75 to be a very digital beep - not much nuance at all - a tad more in 2F or monotone but nothing like the experience with an Explorer.

Come on Minelab give us an Explorer VI as light as the XTerra!!



Edited 1 time(s). Last edit at 07/20/2011 09:13PM by Shambler.

I've hunted a LOT with Etrac guys (and V3) using my F75 LTD.

From what I have seen, in my soil, hunting the areas I mostly hunt (parks, some demo scrapes, etc.) the Etrac are superior machines for sniffing out deep silver, especially smaller silver (dime sized and smaller). I've seen them again and again hunt in heavy pull-tab, bottle cap, or other modern trashy areas trump the F75 LTD on small silver. One of the biggest issues I see with the F75 LTD (at least out here hunting in mineralized inner-city parks) is that EMI is a MUCH bigger issue for the Fisher then the Minelabs (I'm sure their affected by it to some degree, but their 'noise-cancel' seems to do a good job of changing frequencies to work around EMI most of the time.

Don't get me wrong, when the F75 is on, it's a force to be reckoned with, but there's a lot of variables that can hamstring it.







Shambler Wrote:
-------------------------------------------------------
> It would be interesting to hear from the singe
> freq guys that hunt side-by-side with experienced
> explorer/etrac hunters. The super speed and
> "tight foot print" just doesn't seem to have much
> real world impact at all. I've seen may single
> freq users list their unit on eBay after getting
> pummeled a few times in finds - AND if you compare
> actual deep signals, I've seen two people
> literally pack up and go home since no matter what
> they did, they couldn't coax that signal (even to
> grunt).
>
> IMO - in heavy iron, they all suck - albeit in
> different ways.
>
>
> Minelab got it all together when they came up with
> the E-trac.
>
> Couldn't disagree more. They took a step
> backwards with the FE12 line. There's magic in
> the Explorer S curves once you understand it.
> They abandoned their loyal customers in favor of
> the detectorist who needs mo' easiness. I still
> hold hope for an Explorer 5 or 6.

Maybe what is needed is a lower operating frq machine based on the F75.
Like one that is optimized for silver.
Can that be done?
The reason I ask is I read somewhere long ago, don't know if it is true--that a higher operating frq detector can
be driven harder than a lower operating frq detectors......don't know why that would be true.
I have read comments from Omega owners...wishing for a Super Omega.

Steve, Dave Johnson has said that the frequency is becoming less important in modern detectors. But that said, I to think that a lower frequency might have issues with higher recovery speeds (though the Omega sure is nice.) Yeah, lots of us Omega users would like a Super Omega, it's not that much of a reach when you look at the current performance. But, now that I also have a V3i I can say it is MUCH deeper than my Omega 8000 (by like 40%-50%). That said, I've hit a spot hard with my V3i (3 freq mode) that I have pounded with my Omega and I only found 4 more targets thus far, all of them low VID targets (2 hammered coins at 3"-4", a button at 4" and a small ammo chain (bracelet sized) at 9" - deepest find yet). The smaller silver coins that I sometimes find obviously don't "sink" (displace) very deep. I sure do miss the light weight of my Omega as the day after I use the V3i my back is sore, but I'll try shortening the shaft. If the pain doesn't go away I may be forced to another detector which is sad as the V3i is a snap for me to use and I just love playing with it.

I never got the depth on my T2 that others got. (moderately mineralized ground and not too bad EMI). Once I got the Omega I started regularly digging 6" (sometimes 7" targets). I am still amazed at how deep the V3i is, even with the recovery fast.

Last thing, quite a few higher frequency machines are very hot on silver (I think the X-5 is one if memory serves correct). There are so many variables to be played with these days that I wonder if the old frequency adage regarding conductors is just about over.



Edited 1 time(s). Last edit at 07/21/2011 10:03AM by earthmansurfer.

As with any deep target................the graph/smart-screen of the Minelabs..............................................vs..............................................the VDI of other detectors can/often jump all over the board. A astute user can extrapolate the averaging 'general' conductivity of the deep target..... whether it be Explorer graph....or VDI screen.

If the deep target is solo (by itself with no other target near)......the VDI units and graph driven units will be more 'locked on'.

Cal_cobra Wrote:
-------------------------------------------------------
> I've hunted a LOT with Etrac guys (and V3) using
> my F75 LTD.
>
> From what I have seen, in my soil, hunting the
> areas I mostly hunt (parks, some demo scrapes,
> etc.) the Etrac are superior machines for sniffing
> out deep silver, especially smaller silver (dime
> sized and smaller). I've seen them again and
> again hunt in heavy pull-tab, bottle cap, or other
> modern trashy areas trump the F75 LTD on small
> silver. One of the biggest issues I see with the
> F75 LTD (at least out here hunting in mineralized
> inner-city parks) is that EMI is a MUCH bigger

> issue for the Fisher then the Minelabs (I'm sure
> their affected by it to some degree, but their
> 'noise-cancel' seems to do a good job of changing
> frequencies to work around EMI most of the time.
>
> Don't get me wrong, when the F75 is on, it's a
> force to be reckoned with, but there's a lot of
> variables that can hamstring it.
>
>
>
>
>
>
>
> Shambler Wrote:
> --------------------------------------------------
> -----
> > It would be interesting to hear from the singe
> > freq guys that hunt side-by-side with
> experienced
> > explorer/etrac hunters. The super speed and
> > "tight foot print" just doesn't seem to have
> much
> > real world impact at all. I've seen may single
> > freq users list their unit on eBay after
> getting
> > pummeled a few times in finds - AND if you
> compare
> > actual deep signals, I've seen two people
> > literally pack up and go home since no matter
> what
> > they did, they couldn't coax that signal (even
> to
> > grunt).
> >
> > IMO - in heavy iron, they all suck - albeit in
> > different ways.
> >
> >
> > Minelab got it all together when they came up
> with
> > the E-trac.
> >
> > Couldn't disagree more. They took a step
> > backwards with the FE12 line. There's magic in
> > the Explorer S curves once you understand it.
> > They abandoned their loyal customers in favor
> of
> > the detectorist who needs mo' easiness. I
> still
> > hold hope for an Explorer 5 or 6.


the question begs! HOW is the trac doing this? finding more deep silver in trash laden parks?
does the disc. programs on the "trac "null" out on the junk,and just pick up the "Non-ferrous" hits?
the trac's processor is slower than the f-75's i would think the advantage in the crap would go to the fisher!
or does the multi-frequencies play an important role in separating the junk,so the trac can isolate the deep silver better?
comments? WHAT IS this so called "superior" advantage of the e-trac in "dirty" old parks? comments?
thanks!

(h.h.!)
j.t.

I'd like to hear others (technically) answer this question also.

Here's part of the answer, for me anyway...

The Minelabs "false" less often than my F70 did -- allowing me not to have to stop as often to "interrogate;" further, many of the "false" hits on an Explorer are, for me, a very clearly distinct tone. High tone -- yes, but higher than silver, and sort of "empty" and "flat" sounding. Nothing like the "warbly" sound of a deep silver coin. With my old F70, the high-tone false chirps were identical, to my ears, to the high-tone chirps of a deep (and thus imperfectly ID-ing) coin. So, I can pass right over a majority of the iron trash, as it either nulls, or it gives a very distinct-sounding high-tone false. SOME bent, rusty nails sound like a coin, but much of the iron either yields a null, or a very distinct-sounding false tone.

As a result of this, I dig WAAAAY less junk with my Explorer than I did with the F70. Plus, I believe that I pass over WAAAAY fewer "good" targets, that before with my F70 would have often been lost in the barrage of falses, but now are discernable from the (less frequent and more distinct-sounding) falses. I am not sure of ALL the reasons WHY the Minelabs work better for me, but they do, and I think this is one of them. They flat-out find the silver.

By the way, I'm not sure the Explorer/E-Trac's processors are all that slow...just open up the screen (use all-metal/no discrimination), and listen to the machine-gunning of targets in trash-laden ground...it recovers awfully quickly. I think the reason these machines have a "slow" reputation is that when using disc. (which most folks do), these machines will sometimes stay in a "null" for LONG periods of time. But, in my opinion that's not because the processor is "slow," it is simply because there is ALOT of iron trash in the ground, whenever this sustained nulling is occurring. I have proven this to myself by switching to all metal and listening to that machine-gunning of the low tones, showing just how much iron is indeed present in that area.

I have come to think of these sustained periods of nulling as simply the machine showing you when "iron masking" is potentially occurring. It sort of "detects" areas where iron masking is likely to occur (which, to me, is beneficial information to have -- and also is information that you don't get from an F-series machine). In other words, if you disc. out iron on an Explorer/E-Trac, then anytime the predominant target your machine thinks it is "seeing" is iron, it will "null" your threshold. So, when nulling is occurring -- then you know that one of two things is occurring -- either A.) there is only a disced-out target (iron) under the coil (and thus POTENTIAL for iron masking), OR, B.) there is iron AND a good target(s) under your coil, but (if the nulling persists) the machine can only see the iron (and thus CONFIRMED iron masking). On the other hand, if you are nulling due to iron, and then your machine gives you a high-tone peep, and you then dig and recover a good target, then that target, by definition, was not fully masked -- and thus your "threshold null" was broken by the good target.

Not sure if this makes sense, but I have learned that I like knowing when iron masking is occurring, and when it's not, and this is information you can easily gather based on whether your threshold is nulling, or it's not (disregarding, of course, silent masking).

To elaborate...using threshold nulling as a guide, I can hit a new site, and in two minutes, know if I need to use a slower sweep and a smaller coil -- as the degree of nulling clues me in instantly to the amount of iron trash present. An example was at an old church (first built in 1800) that I hunted recently. This church was torn down/rebuilt (presumably due to fires) on three occasions. By looking at the subtleties of the ground/terrain, I could see areas where dirt had been scraped away from the foundation of the burned/torn down church (and then re-leveled for subsequent rebuilding). Then, by running the Explorer and observing the nulling of the threshold, I was easily and quickly able to precisely outline the boundary of where the dirt scraping ended and the "clean ground" began, as the dirt which was scraped away from the burned-out foundation obviously contained nails and other iron fragments. I outlined the perimeter of the "scraped dirt" area, and then hunted the "unscraped/virgin" dirt area on the first day. This hunt yielded a couple of late 1800s Indian Heads. The next day, still using what I learned about the iron trash content of different areas around the building, I dove right into the areas where the nail-filled soil had been spread away from the foundation of the building. In this area, I used a small coil, slow sweep speed, an "open" screen (no discrimination), and ferrous tones (meaning that "high iron content" objects would low tone, and "low iron content" objects would high tone). Using this method, I was able to sneak out another late 1800s Indian Head (before the barrage of tones wore me out for the day!)

I know I got off on a tangent there, sorry! But I wanted to illustrate that that's another way that I prefer the Explorer over the F70 -- it is possible to use "nulling" to your advantage, as a hunter.

Anyway, not sure if any of this helps at all, but wanted to add those thoughts to the discussion.

Steve



Edited 3 time(s). Last edit at 08/08/2011 04:19AM by steveg.

Well put Steve. There are people that say they find targets even in null. But like you its coming off the null NOT in null. The machine is telling you to slow down.... much like a stuck smartscreen does with to much sensitivity in trash. You will not you are getting tones... but the screen isnt moving. Thats why tone hunting in trash is the only way to hunt these spots. Also, the exps require almost no movement to pick up targets unlike some of the single freq that need the faster movement for the filters to work properly. I think sometimes people using fast recovery machines believe that means swing um like a golf club. If you do you will be missing targets. Even with a fast recovery machine i like to use a fast wiggle in trash as apposed to a fast swing. Some people dont like the PAINTING motion swing of an exp. but i think the results speak for themselves. A lot has to do with learning any machine properly.

Dew

In regards to your statement....."A astute user can extrapolate the averaging 'general' conductivity of the deep target..... whether it be Explorer graph....or VDI screen."

Recently a poster on FMall asked...........
"Ok I have a really tech question for the ones of you that actually understand what is under the hood of a 75 ltd.
I do not have a lot of tech experience on electronics or any thing related except for high freq welding; tig;
Here is my ? to you that might have a background and tech info on the machine;
When you have a high freq welder the sine and wave thing goes plus neg up and down; do these metal detectors have a simular event in them? Why is i have noticed that at times quite often actually i get a number on a pass of like a 30 a 50 and a 80 ( not actual numbers) two of the numbers in the swing will add up to the third or such combo: These numbers bounce arund but usually the accurate number will repeat the best but not always. today thirty 40 and 70 came up and it best to the seventy which should been a dime or early penny but it was a nickel:
Just wondering if anyone thought or had reason to believe it is a anomoloy howeveryou spell that; in the elec that causes the numbers to multiply divide or such mathmatically like a sine wave?"

Dave Johnson's reply was.......
"If two consecutive numbers add up to a third, it's just coincidence."

Is the question the FMall poster asked..........the same principle as what you are referring to with "averaging"??

VERY well stated Steveg...... and easily understood. Truly appreciate your 'take' on your experiences...... as I can fully relate this to nearly any unit. Learning the 'nuances' of each units 'language' is superlative to real-world end-resultant performance.

The 'averaging' question....... appears to have been mistaken for 'additive'...... and is incorrect...... in addition (as Dave J puts it) "just coincidence".

Can you give an example of averaging that you have experienced....the numbers you got.....and what the target actually was....what baseline do you use to calculate an average. Are you using 3, 4, 5 etc readings? Where do you draw the line in # of readings to make the average? Are you using the full range of ID's presenting themselves or more closely grouped ID's that are more predominant?

I haven't used the 75 or 70 but I did have an Xterra 70 with a small hf coil for a while.
So this is what I noticed, not only with that detector but other hf detectors as well.
When sweeping over targets, I got spike readings and/or tone changes related to higher conductors.
Some nails would give off those spike readings and high conductive range numbers.
Even mid-range and low-range conductors would have higher spike readings.
What I quickly discovered is most of the time if I stopped and isolated the signal and tried
to get dead center with my coil that I generally could get a good idea as the meter reading
would seem to settle into the correct area for which the target should be IDed.
Even though this was most of the time true, there were times I was fooled by the ID I got.

Personally I think it is the behavior of the high frq. machines in general to be at least somewhat
sparky and perhaps this is because they are also generally highly sensitive machines to start with.
Some can learn to deal with this quite effectively and doesn't cause them much concern.
I would suppose many coin hunters will find this distracting since they are going for items
in the mid to high range conductors (for the most part).

One way to correctly think about detectors is to realize that they are just tools....
So just as a carpenter may have several hammers or whatever else you may want to make an analogy with.....
There should be times when those high frq machines are needed and other times when a more stable
lower frq or multi-frq will be a good choice (certainly wouldn't hurt to have one of each).
Could it be that simple? I think so.

Good analogy Steve. Yes..........the higher operating frequency units do indeed tend to 'up-average' the ID of the actual object........especially in the presence of iron oxides...... ie tiny rust flakes. The higher the operating frequency..... the more 'hyper-sensitive' the unit will be to low conductive items such as iron/rust flakes.

Terra.....I do recommend reading the threads on this forum titled COMPILATION #1 and COMPILATION #2.......in addition to "Rcpt Ack of F75 LTD prototype". I cover your exact questions.

I will give a short example: Found a 7" deep Buffalo nickel with F75. Out of the ground......the nickel reliably ID'd as a '29'. In the ground....was a different story. First ..... the nickel was 'up-averaging'.... as far as ID goes. In addition......it was ID "bouncing" in a VDI range from 28-to-48. My initial guess....was the target is probably truly around a '38' conductivity; YET..........knowing there were plenty of rust flakes....... I did realize this would cause 'up-averaging' of the actual conductivity of the target. ((( Interestingly......the CZ ID'd this target....almost reliably as 'iron'.....with an occasional high-tone chirp....that of a 'false' high-tone chirp ))). With the F75....... I could rotate my body around the target......and watch the targets take on a higher ID range...................then.............continue my body rotation around the target...........and at one point the target would take on a lower ID range. There was even a point of body rotation unto which the nickel was ID'ing as constant/consistent iron.

This is just one example.

Tom - I read that coins in the presence of iron would be down-averaged (as the iron is low on the VDI scale) and those in salts would be up-averaged.
However, in my test garden I have observed EXTREME up-averaging - my garden is FULL of iron.
Do things vary here?

I reported this (to great extent) in one of the threads.....(( COMPILATION #1 or COMPILATION #2..... or in Rcpt Ack of F75 LTD prototype )). In general...........flecks of rust will cause a target to 'up-average'. . . . whereas... solid iron objects (like nails) will cause targets to 'down-average'. Mineralization adds to the equation also.
Mineralization is somewhat unique in the fact that it'll cause targets to up-average ... as long as the targets are shallow-to-medium depths. But..... when the target is fairly deep...... mineralization (in general) will cause a target to ID as 'iron'.

This holds true for most scenarios..........but not all.

Tell me if I am wrong,,,but they droped some stuff when they went from the SE to the E-Trac right ??
Several XS's,Several Explorer ll's 2 E-Tracs,1 SE and now use the SE Pro....
On the E-Trac, if i remember right the Ferrous sounds were different sounding and could not be ajusted to the same high pitch like in Con.,,,right ????
Also the SE in Pin Point mode still showed the depth and numbers or cross hairs,,not sure on the E-trac, but don't think so..
There were things that I liked about the E-Trac but was to use to the "S" curve...

Most of my hunting is in old parks,school, and old house lots with lots of trash.....
I have never had a problem with EMI with my Explorer's or E-trac's, and my CZ 3d,,,but other units had to be put up because of EMI.
The last F-75 that I had loved anything iron and it had a new coil, but maybe it was bad...
I will say that if I am hunting in rusty bottle caps, give me a Explorer SE, they have there own special place on the screen....
Love those Ferrous sounds.......

Every unit I ever had, found stuff,,so what ever unit you know and under stand and like and works in your area, use it.....
HH..BJ

Tom, I love your nickel analogy. I have gotten pretty good at digging the V's and buffaloes because the up averaging makes them stand out more for me than the surrounding pulltabs. I keep telling myself that if I can usually recognize a deep old nickel because of sound and VDI surely a gold coin will be similiar. In your experience do they tend sound out like a coin and do they tend to up average also?

Almost exactly like a nickel. And they will also up-average or down-average ( IRT the VDI ) if in the presence of iron oxide or iron...... respectively. They are a 'coin-sized' sounding pull-tab reading...... with a bit more audible 'authority'.... due to density.