Alert to prospective buyers of the X-terra 50....

[Cody]

Nice chart.

The DFX engineers do some magic with this to make it more user friendly thus the graph and VDI numbers are a little different. Ralph, I think true all metal is the old TR type that does not reject ferrite or refined iron. A true all metal detector does not reject iron in any form, natural, or refined and used the distortion of the signal to induce a signal into the receiver coil.

Once we go to ground balance we then have zero discriminate to refined metals and balance to ferrite. The old CoinMaster5 was not a true all metal detector as it rejected iron minerals. I don't think Minelab has ever manufactured a true all metal detector. The Advantage is a zero discriminate all metal to refined iron with discrimination of ferrite. The true all metal detector have very little depth in iron minerals so what we think of as true all metal is actually zero discriminate. If we then consider TID then it gets a little more complicated.

However, all metal with discrimination to soil minerals and zero discrimination to refined metals is the best I have seen for depth. In my opinion we will get a little better sensitivity and thus more depth with a threshold.

It is hard to get a manufacture to define "true all metal detector".

 

[Cody]

I am very interested in how you define "true all metal" as I have not seen any VLF with true all metal as I under the operation. We have not had true all metal detectors since introduction of ground balance and discrimination. All VLF ground balance detectors use some form of zero discriminate all metal since the reject salt and iron minerals or just iron minerals.

I would appreciate a definition of "true all metal" for my own personal understanding. I don't know if others are interested but this is something that I thought I understood as the old TR that accepted all metal including iron minerals. I have searched all my resources and only find the old TR/IB or BFO to be true all metal so am trying to fill in the gaps.

 

[Ralph Bryant]

To me, "true" all metal is just that......a machine that will accept and SIGNAL on all metals down to the slightest natural ferrous up to the highest ranges of the conductivity scale (pure silver). As you say, any machine that is capable of discriminating even the lowest level of ferrous signals OR is even capable of being "ground balanced" is performing some level of metal rejection, even if slight. There is no "in between".....it is either ALL METAL or not. I think some mistake the term "threshold-based" for "true" or "conventional" all metal, when in fact that is not the case with these newer-breed motion machines. There is no doubt some slight advantage in listening for very minor variations in an audible threshold over having the machine designed or tuned just below the threshold into the range of silence "if" it is truly "just below" the audible threshold. Problem is, you don't have much way of being sure just HOW FAR below the true threshold point it may be tuned. In that sense, there is some degree of psychological assurance too in having the threshold audio in the background. I still think though, that other than fringe range or very small targets that tend to give only the slightest of signals to begin with, there is really little benefit to threshold-based over silent-search, all things being equal as to "proper" tuning just below the point of audibility.

Ralph

 

[Ralph Bryant]

Hi Cody,

I really prefer the White's VDI system over any other because of the range of numbering they use. It is much closer and more logical in comparison to true relative conductivity on the non-ferrous side than any other on the market that I am aware of. Somewhere I have a little booklet that White's produced several years ago talking about their VDI range and how it relates to a similar chart as above.

For pure simplicity, I also like the way Minelab has arranged the Xterras and allowed full-range notching in any or all segments and the lack of "icons" trying to tell us what a particular value is in the way of the target. Leaves a little more to the imagination and intelligence of the operator IMO.

We also keep hearing about how threshold-based "always" goes deeper than silent-search motion-based discrimination. One obvious and interesting exception to this rule that I can think of right off the top of my head is the Nautilus DMC IIb. Even with the AM mode sensitivity at a high level, the discrimination side will invariably give a stronger response beyond what the AM side will pick up at depth. Probably the deepest "accurate" discrimination circuits on the market.

Ralph

 

[Anonymous]

Back in the ' 70s there were units that were sold as induction balance, and were different from normal TR. Any ideas?

 

[Cody]

You know we get into that depth thing which is kind of like saying I cannot hear a pin drop because I don't have my hearing aid turned up enough but we are standing next to a jack hammer.

Years ago we were lucky to 3 inches most of the time and a really deep coins, 5 or 6 inches would have this very soft mellow tone. If we could keep the threshold fairly solid at a nice sound just above silent we could hear those soft mellow changes. I think the idea of a threshold comes from that and that we got use to a threshold to tell us what was going in the soil. How, much difference does it make if there is or is not a threshold? My guess is the high gain circuits of today are better off with silent search to stop the chirping and sounds of tiny bits of trash that is the jack hammer noise I refer to.

Another problem is we confuse decreasing the threshold to below sound and a detector designed to keep the threshold just slightly below sound. In one situation we know where the threshold is. An example is the Explorer that can be set to just below sound or at some point higher.

I have never agreed that depth is depending on that kind of thing but how well can a user pick faint sounds that are good targets from the composite signals in the receiver. One guy can take our detector and get twice the depth we can because he can pick the faint targets out while we may not get anywhere near the depth with our machine. I don't think depth is a threshold or not question but one of skills. So, we go on and on about this or that machine and setting. The entire detecting community can be getting 10 inches with a detector and a user will have problem getting half that and swear other users are not telling the truth. What do you do Ralph?

I have always felt that the real test is the guy that can take just a Jetco and run circles around a guy with an Minelab, Fisher, Whites, then run circles around a Jetco with dousing rod. Ha, it is an endless debate................chunking rocks at the moon.

 

[Ralph Bryant]

I think I need to start using that as the header to all of my posts, like my Trademark / Motto.

I recently bought another Tesoro Compadre from Buckeye Brad and was out playing with it the other day, thinking to myself "MAN ! If we had only had something this simple and this good back in the 60s, we could have really cleaned up the neighborhood...." This newest one (I now have 3 Compadres, all with different coil sizes) is their latest version with the 5.75 inch coil, and performs in trash almost as well as the one with the 4 inch coil conversion, with the addition of 2-3 inches more in depth. And as simple as they are, I always end the day using one by shaking my head and wondering why I spend so much time chasing bigger, better, and deeper detectors when I get so much enjoyment out of these little machines. I know others who have run the gamut of very basic to mid-range to top of the line, returning to very basic machines for the majority of their casual coinshooting pursuits, and who will on a regular and consistent basis, find more during any given time period than most others using their meters, tones, bells, and whistles. I think too, at times, it is really unfortunate that more detectorists don't take a much closer look at simplicity in favor of complexity. Sometimes that's what it takes to really get back to the basics of our hobby, and finding that "fun-factor" again. Remember your first simple machine, and how you enjoyed it in comparison to spending so much time trying to read the machines and analyze the targets in the ground with todays "do-it-all" detectors ?

Chasing those ever-distant "bigger, better, & deeper" machines, never really getting beyond the "hope" itself, is what I'm talking about here. I think that's what attracted me to the Xterras, a little bit of basic performance mixed with a little bit more modern technology in a simple TID set-up for more casual use or for more serious hunting either one, without the need to jump off the deep end.

This whole hobby sometimes seems like a vicious cycle of simplicity to complexity and back again, depending on the years we've been involved in detecting and following the machines through their phases of evolution.

Like the Neanderthals, we start by coming out of our caves into discovery, and spend too much time "chucking rocks at the moon" until we finally realize and accept the futility and impossibility of ever really hitting our target.

Thanks for reminding me.

Ralph

 

[OldeTymer]

Ralph,

I agree with most of what you said. However, you need to remember that back then we didn't have the choices there are today. Most of the detectors in the late 60's and early 70's were those very simple, one or two control units as that's all that was available. Yes, it seemed to be more fun back then, but remember too, most areas weren't hunted to death as they are today. Almost anywhere produced a pocket full of silver coins. There weren't as many trash targets to contend with either. Back then people tended to put their trash where it belonged. They didn't just throw everything on the ground like they do today, and there just weren't as many doing it back then.

The longer I'm in this hobby, the more I like the simpler machines that still offer decent performance. Having a machine that eeks the maximum amount of depth possible requires much more complexity to do so. It's just not that critical to me. Getting in between all that trash is more important, to me. I guess that's why I really like seeing companies like Minelab, Fisher, Garrett and Whites coming out with decent performing machines that are not only much simpler to operate, but are much lighter on these old bones. I really hate seeing the "mines better than yours" struggles that go on. All of the big names make good units that perform about the same. If only we would have had some of these back then.

OldeTymer

 

[Ralph Bryant]

I think we're pretty much on the same page here. I spend most of my detecting time anymore in very trashy areas, places most hunters in this area avoid like the plague because of all the modern (and not so modern) trash. Target separation is just as important to me as "depth", and is why I prefer some of the machine/coil combinations I do for that specific type of hunting. I know alot of detector users just don't understand the concept of a $150 detector working better in some situations than that $1200 top end unit they are so proud of, but like they say "you don't drive nails with a screwdriver".

True that many areas are hunted to death these days, compared to the 60s, and that many of the machines then were just simple one-knobbers. That really was my point in saying I wish we had had some of these simpler (but much better performing) machines back then. Another advantage to the "good old days".......NO PULL TABS !

You mention lighter and easier to swing machines. I just put my favorite little trash machine on the digital scales, and it weighed in at a whopping 26 ounces !

Ralph

 

[BuckeyeBrad]

n/t

 

[jtalley007]

Many detectors today have a true all-metal mode that we consider as part of the definition compared to a detector that has a motion based all metal mode. Some of these have zero disc. but still have to be moved to respond compared to say a all metal mode on one channel of the Nautilus DMC 2-B. I know if you get really technical you guys are probably correct since Cody is very sharp with metal detector technology. But for all practical purposes any of todays detectors that respond to say a rusty nail after they are ground balanced still pick up ALL METALS.

 

[Ralph Bryant]

Rusty nails can vary, having phase angles of anywhere from about 20 to 45 degrees. From 0 to 45 degrees is 25% of full discrimination range, not exactly splitting hairs. Technically, if you had a detector with a "160 degree" discrimination circuit (20 degrees and higher), it would still not be considered a true "all-metal" machine, even though it would detect a rusty nail. Neither would any ground balancing machine (technically) because there is always a point in the scale that is discriminated out (the ground phase), but that probably WOULD be splitting hairs. Our arguement here is that a machine is either "all-metal" or it's not, regardless of an audio threshold. Even ferrous ground mineralization is "metal" in a sense, just run a strong magnet through it and look at the results. Is a silent-search machine without a threshold any less "all-metal" than a threshold-based "all-metal" machine if neither can detect a specific metal target, whether due to its small size or being just outside fringe detection range ? Alot still depends on the basic design and capabilities of the machine. A threshold-based AM machine might detect deeper than a motion-based silent-search machine, but it could just as easily be visa-versa if the silent-search machine has better inherent depth capabilities. There is more to consider than just one type of operation vs. the other.

Ralph

 

[Anonymous]

Run your DMC2-B in 0 Disc., and you will still not be able to pick up some signals in the VLF-DISC that literally scream at you in the Non-Motion VLF Mode.

 

[Digger]

Whites IDX series, Garrett Master Hunter CX or a Tesoro Amigo? The reason I ask is that all of these were referred to as having an "all-metal" mode. In reality, all of them used zero discrimination. HH Randy