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►Warning -- this is Lengthy: Tesoro Discrimination Acceptance Ranges ... from Pre-ED to the present.

November 09, 2018 10:31AM avatar
Drew, you have basically asked three of the main questions people have had for as long as I have been using and enjoying Tesoro detectors, and that started shortly after Jack Gifford started his new company and released his first detectors ... and regularly since July of '83.

I've lived in major metropolitan cities like Portland Oregon or Salt Lake City, Utah suburbs, as well as modest-sized sites to small towns like Vale where I am now with about 1865 people, to dinky Arlington Oregon where they have about 525 folks. And during this time I have traveled to even larger cities, as well as frequented many forlorn and long forgotten ghost towns, many of which are virtually indistinguishable unless you knew they were there and walked around to spot some evidence of their former existence.

In short, I have been to virtually any type of site environment in my travels for Coin & Jewelry Hunting as well as serious Relic Hunting and have always carried and used some of my favorite Tesoro models. The right detector and coil combination can make a terrific 'general-purpose' detector. And I can guarantee you my Tesoro's have proven themselves to me countless times in any application. That includes when I have relied on them for several contract searches for Cache Hunting, too.

Which of the current Tesoro machines have ED 180, which have ED 120, etc.?
If Tesoro Electronics has closed their doors to manufacturing metal detectors then we'll just ignore the reference to 'current' or most recent products and address ALL of Tesoro's motion-based Discriminators since the introduction of the Inca in July of '83. Back then, Tesoro models used a variable Discrimination adjustment that was fairly similar to what most detector manufacturers were doing, and that was rejecting all iron plus a little bit into the thin, small foil (very low non-ferrous) conductivity range at the minimum Disc. level.

The bulk of the detector users have been average Coin Hunters and they don't like to hear or recover junk, especially nails and other iron debris, therefore most Discriminators rejected iron and some other lower-conductive targets often considered to be trash. That way, Coin Hunters found more coins and didn't hear, thus didn't recover, so much junk. Later I referred to that early Discrimination acceptance range calling it a 'D-90' or 'D-100' range of acceptance. Those were simply my terms, not any sort of industry reference, to try and describe how much of the upper conductivity range was being accepted so as to produce a good signal.

Note that I call reader's attention to the word 'acceptance' because that's what we are really concerned about. How much of the 180° range of detectable metal targets ... ferrous and non-ferrous ... the detector is going to accept and process above the adjusted level of Discrimination. Okay, right about now some folks are wondering what I mean by 180° range of acceptance. Well, let me answer that, and while doing so I'll even through in the confusion of the numeric VDI reference some other manufacturers have used other than Tesoro.

'0' to '100': Many of the earlier Target ID detectors used a needle meter with a display that was scaled from '0' to '100' and the named references along that scale started with Iron and progressed to a higher-conductive object such as a US Silver Dollar. The very bottom of that lower left-end could reflect a GB adjustment to deal with iron mineralized ground and virtually all man-made iron targets, then progressed, generally increasing in read-out relative to the increase in an object's conductivity. That design worked and is similar to what I use in my seminars with my Teknetics Mark I Ltd. to help display a conductivity scale.

'-95' to '+95' A great example of this Discrimination scale is a White's XLT. While their needle meter models, like the 6000 Pro XL and those before it, used the above described scale, somebody chose to use a broad-range read-out for the XLT and a few models since then. They try to explain that this 191 numeric scale represents things the detector might respond to from iron to lower conductive ground, like wet salty sand or salt water, on up through higher conductive targets such as a big silver Dollar.

With 95 minus numbers plus 95 positive numbers, plus the '0' in the middle, it just doesn't seem to fit with the first concept even White's used with their needle meter displays of '100' numbers to now have '191' numbers. I know many people who think they need to reject everything from '0' on down, or even into the lower-end of the positive numbers up from '0' with an XLT, but I don't. My most used 'Bushwhack' program for the XLT accepts everything from -40 up to +95. I've been hunting with an XLT and my Bushwhack program since '94 and have always been successful. But with those settings, why?

Simple. I don't like to use a too-bold Disc. setting and I found many small, thin, non-ferrous items that produced a VDI read-out below the '0' reference and into the '-' numbers. I was working my XLT w/6½" Concentric coil in a woodchip playground where the 'chips' were deep. The dirt ground level was a good 8" below the surface of the chips, and 8" of dry woodchips isn't much of a mineralized challenge. I had a good repetitive signal that kept a tight numeric VDI readout of '-14' sometimes dropping to '-12.' At 2" deep in the mellow woodchips I recovered a small 14K gold child's ring w/a green or purple stone.

I have also found thin gold chains, gold ear ring studs and other dinky or thin low-conductive gold items that read in the -12 to +6 VDI range, therefore with my Discrimination set to 'accept' everything from -40 up to +95 I have few concerns about missing desirable targets.

Back to Tesoro's 'ED' references: Jack Gifford took a very logical approach, in engineering reference, to describe the range of 'acceptance' of his detector's Discrimination modes. Whereas most of his models followed more-or-less a general trend of having a bolder lower-end setting to knock out all iron and even small, thin foil, he did bring out the 'original' Lobo in December of 1989, and produced it through June of '97, even thought the Lobo SuperTRAQ was introduced in January to start that year. With the Lobo he chose to describe the Discrimination as ED-180. Since the Lobo was designed primarily for gold nugget hunting, and tiny, very low conductive gold nuggets can be easily rejected, he felt it best to accept ALL metals, ferrous and non-ferrous, so designed the Discriminate circuitry to have a minimum Disc. setting that would 'accept' all metals and basically have no metal target rejection..

I can't draw on my computer, and have a tough time with stick people to show a difference between guys and gals. I explain that when I do my seminars and draw on my marker board to help visually describe what I am trying to verbally explain. I draw a sine wave and describe it as it was drawn and explained to me by John Earle, design engineer at Compass Electronics. When I worked there I called their attention to a glitch in calibration of their new XP Pro Scanner series that wouldn't respond (detect or beep) a silver dollar or often even half-dollars.

If you look at the upper half of a sine wave it generally represents the range of acceptance from very low conductivity to higher-conductivity, going from left-to-right. Now, looking at that upper sine wave, imagine a simple drafting compass showing half of a full circle, representing 180°, with reversed numbering scale. That is, at the far left side at the parallel base-line where the sine wave starts an upward arc, would be the 180° start and at the peak of the arc would be 90° and continue to the far right side where it would be 0° as the sine wave drops below the base-line.

Now you can vision the Lobo's ED-180 Discrimination. Where most detectors made were only accepting the upper portion, which I referred to ad D-90 to D-100 with the 'D' meaning Discrimination and the number of '90' or '100 suggesting that at the minimum Disc. setting the detectors would respond to metals with conductivities above (or to the right on the scale) from 90° or perhaps 100° on down to close to the '0' mark. That was the range of 'acceptance'.

Jack was informed by some avid detectorists that most of his models had too much rejection at the minimum Disc. setting and were actually rejecting some very small, thin gold jewelry. The Lobo with ED-180 would signal on the gold as well as lower-conductive iron trash at the minimum setting, and could be adjusted to reject nails and most common iron debris and still 'beep' on lower-conductive non-ferrous targets.

So, in March of 1990, Tesoro introduced their 'original' Bandido which was the first model to feature what Jack Gifford described as ED-120 Discrimination. The 'ED' refers to 'Expanded Discrimination' on the lower end of acceptance, and the '120' refers to being able to now 'accept' the upper 120° of that sine wave.

Thus, most Tesoro's brought out after the Bandido's introduction then featured ED-120 Discrimination, and that knocked out iron nails and most common man-made iron trash. Plus a few models that featured ED-180 Disc. for all-metal acceptance at a minimum Disc. setting. Then there were the 'tweeners. The models with Discrimination that was kind of in-between ED-120 and ED-180 Disc, such as the Vaquero and Cibola, and just a few others.

When introduced the Vaquero and Cibola were described as having ED-180 in the literature and ads, but they didn't accept all metal at the minimum Disc. setting. However, they would respond to some iron such as most common nails and similar conductive iron junk, so at their minimum Disc. setting they accepted or responded to more targets with lower conductivity levels than ED-120 and that range I generally describe as ED-165.

Sorry for the rambling but I hope it helps describe Tesoro's descriptions of Discrimination designs. Looking at most of the more recent Tesoro models or even going back to March of '90 when the ED-120 Disc. circuitry appeared in the Bandido, they can be grouped like this, not in order of introduction, just alphabetically:

Models with an ED-180 Discrimination with adjustable range of Acceptance at the minimum setting:

Amigo II
Euro Sabre
Lobo SuperTRAQ

Models with ED-165 Discrimination:

Golden Sabre (4-tone models)

Models with ED-120 Discrimination:

Almost all other Tesoro Discriminators since March of '90.

What are the advantages, strengths and weaknesses of these various range discriminator systems?
The earlier Discriminators, with the slightly limited lower and adjustment I call D-90 or D-100 still work just fine for most types of hunting but, as described, but might not be able to adjust low enough to accept very thin gold chains, ear ring studs and other smaller-size and very low conductive targets.

Many of those early models are still in use and working well, and I have friends who still use these models almost exclusively. Examples would be the original Cutlass, Golden Sabre, Golden Sabre Plus, Inca, Royal Sabre, original Silver sabre and Silver Sabre Plus, Toltec 80 and Toltec 100.

Perhaps the most popular models, at least so far as Discrimination acceptance ability is concerned, would be the ED-120 models that generally knock out iron nails at minimum Disc., but respond so well to 'individual' targets we encounter even if smaller, thinner, and lower conductive non-ferrous specimens. Most of my all-time favorite Tesoro models feature ED-120 Disc. circuitry. Here are some examples of these more popular offerings:

(NOTE to those new to Tesoro products: As you read this list the µMAX description us used. That is a µ symbol and not a letter u so it is pronounced microMAX and not uMAX. Jack used the electronics micro symbol of µ to describe the micro-sized control housing that was used for these models that still provided MAXimum performance.)

The Bandido 'series' of Bandido, Bandido II, µMAX Bandido and Bandido II µMAX, Conquistador µMAX, Cutlass II, µMAX Cutlass and Cutlass II µMAX, Golden Sabre II, Outlaw, Pantera, Silver µMAX, Silver Sabre II and Silver Sabre µMAX and Toltec II.

Naturally, the models with the broader adjustment ranges of ED-165 and ED-180 are designed to respond to some ferrous targets or all ferrous targets as well as non-ferrous. Their advantage is mainly to those who want to find more iron-based targets.

Are some designed specifically for relics and others for jewelry hunting, or coin shooting purposes?
All Tesoro models can find coins, jewelry and relics as long as they fall within their acceptable Discrimination range. As we should expect, there will be differences in performance afield with some models that is not directly associated with the Discriminate control setting and is simply a part of how the internal circuitry design works or handles the rejection or filtering of erroneous noise. The 'noise' can be caused by outside EMI sources or internal 'noise' from closely associated ferrous trash and non-ferrous targets ... that is better known as good-target masking.

Be aware that with any brand or product improvement there can also come trade-offs in performance. In my current 13 unit Detector Outfit I have three of two of my all-time favorite Tesoro's, the Bandido II µMAX (of which I own two) and the Silver Sabre µMAX. These two models appeal to me because they use what Tesoro called "Low-Noise/High-Gain" circuitry.

The "Low-Noise" part of that describes how the circuitry can help eliminate or reduce the 'noise' when hunting in an iron infested site that we can sometimes get from the fringe rejection signal. The "High-Gain" reference means that the detector features a higher receive gain which provides a little more depth and a bit more saturated audio than the prior models that lacked this enhancement.

I use my Tesoro's a lot when urban Coin Hunting and where I lived most of the time was in the greater Portland Oregon metro area, and a benefit of most Northwest USA towns and cities is that the timber industry made available a lot of wood-chips and bark-chips that are used in the many, many, many playgrounds at parks and schools. And there are a lot of parks and schools around there. Plus that was back in the latter '80s and through the '90s when we still saw an ample amount of use of public parks which made tot-lots and other places offer a lot of potential.

Many of those playgrounds were dug fairly deep and filled with several inches of loose 'chips' to help protect playground users from injuries from a fall. Some had shaved wood, small thin wood chips, medium to larger-size wood chips or even bark-chips that were easily 8" to 12" deep. With all the play activity that caused a lot of disturbance and that resulted in a lot of displacement of coins, rings and other lost or discarded metal targets. I wanted to get the best depth-of-detection in those deeper wood-chip filled tot-lots. The Bandido II µMAX and Silver Sabre µMAX quickly became my two #1 Tesoro favorites back in October of '97 when both models were introduced.

Prior to that my main-use detectors from Tesoro included the Bandido II and Pantera, both manual Ground Balance models, and the Silver Sabre II which was a turn-on-and-go internally preset GB model. All three featured ED-120 Disc., but not the 'Low-Noise/High-Gain' circuitry that came later. They all handled most of my Relic Hunting needs very well and, trust me, I spent more time hunting three very productive ghost towns than I did hunting all the urban Coin Hunting sites I could from '83 thru '97. That was due to the terrific performance of favorite Tesoro's in dense iron nail contaminated sites or other small iron type trash environments.

I had those three favorites along when TimberTodd, once a Tesoro Dealer, got in an order that included a Bandido II µMAX. Those came out in October of '97 so I think it was right in that October or the following wetter fall/winter months around the Portland metro area when the order came in. I drove over to meet up and take a look at this new model. Todd might read this and remember the time and interesting experience we had checking that model out.

He assembled it and we did a little quick testing there in his house, then went outside with the intent of adjusting the Ground Balance and checking it out in a dirt environment. It was just dirt when I arrived, but when we stepped out on his nice front wooden deck the rain had arrived (blah!) and what was dirt was transitioning to mud. I can't recall the actual size boards that were used on the covered front deck, whether they were 2X4's or 2X6" or ???, but where the boards butted together the ends were fastened down with two nails or screws in the corners, thus the two adjoining boards presented almost a 4-corner square with the corner markers being the perpendicular screws or nails.

Since it was raining I figured it best to stay dry and I grabbed a coin out of my pocket, it was a 5¢ piece (we call them a Nickel for the benefit of foreign readers) and tossed it down on Todd's deck. Surprisingly it came to rest almost dead center in that 4 nail or screw area. The brand new Bandido II µMAX had the stock brown 8" Concentric coil mounted and when swept across those four fasteners and the 5¢ coin, it didn't sound all that impressive. I know I was surprised. confused smiley

Todd stepped in and got a detector he used and brought it out. Memory starts to fade as we age I guess but if I recall I thought it was a Golden Sabre II. Todd can also maybe clear me up on that, but it had the ED-120 Disc. (if that was the model) but did NOT have the Low-Noise/High-Gain circuitry ... it handled the iron well and signaled on the 5¢ piece. thumbs up

The new Bandido II µMAX did provide improved depth-of-detection and a louder and more saturated audio response than the former models, but the only circuitry difference being the Low-Noise/High-Gain feature seemed to be an improvement, in some ways, but also a detriment. At times you will have some performance trade-offs.

Nonetheless, I still added a Bandido II µMAX and Silver Sabre µMAX to my personal detector outfit but I also retained one or two former Tesoro models and also had one or two other slow-motion/quick-response favorites in my arsenal in the form of White's Classic models. During the next couple of weeks I duplicated a test scenario like Todd's fastened-down wooden deck, and did a few other test scenarios with an assortment of ferrous samaples plus went detecting around a few very trashy sites.

I still preferred my Bandido II µMAX and Silver Sabre µMAX overall, but kept a former Bandido II on-hand for the really dense iron debris sites where target masking was more of a challenge. A later indication of performance differences, I believe it was '98, when our detecting club held a Competition Hunt, but the location was at the Yamhill County Fairgrounds and the site they allowed us to use that had been plowed up was not too bad even though it had been used for demolition derbies. However, the first hunt field was just west of that and it turned out it used to be where they hauled various debris from the fair..

I had my Bandido II µMAX and Classic ID in my vehicle, with 7" Concentric and 6½" concentric coils mounted respectively. But thought I might try using the Troy Custom Shadow X2 which is simply a very slightly changed Silver Sabre µMAX, and had the Shadow's 7" Concentric coil mounted. The whistle blew and the first hunt started. Quickly I discovered that the Shadow X2 was giving me fits with the abundant discarded iron, especially when I saw a coin sticking out half-way from under a flattish iron fastener piece and didn't get any good response.

I darted to my vehicle and grabbed my White's Classic ID which handled iron trash similar to the earlier Tesoro models w/o the 'Low-Noise/High-Gain' circuitry, even though the Discrimination adjusted a little lower than the ED-120 Tesoro's. I quickly balanced the Classic ID and increased the Disc. to where it just barely knocked out an iron nail. I swept over that half-exposed coin and got a good response, bagged the coil and then got busy working the Competition Hunt field.

After that first hunt I heard a few entrants complaining about their detectors being 'noisy' and not working very well on coins in the obviously trashy site. They were all using a Tesoro µMAX model or Troy Custom Shadow X2 which used the same circuitry. Others who hunted by them used former Tesoro models that behaved just fine in the trash. I used my Classic ID for the rest of that 2-day Competition and since then have either kept an original Bandido, Bandido II or Silver Sabre II (prior models w/o the µMAX Low-Noise/High-Gain design) or a White's modified Classic III SL, Classic ID or IDX Pro in my working detector Outfit.

I have now enhanced my Detector Outfit and have models that out-perform all the Tesoro models in really dense iron nail debris to handle target masking, those being my Nokta FORS CoRe w/'OOR' DD coil and FORS Relic w/5" DD coil, plus I have my modified Classic ID w/5½" Concentric Ferret coil for the really tough tasks. I still maintain my Bandido II µMAX and Silver Sabre µMAX for everything I might want to do, anywhere, except the nastiest ferrous debris target-masking places.


"Your EYES ... the only 100% accurate form of Discrimination!"

Stinkwater Wells Trading Post
Metal Detector Evaluations and Product Reviews
monte@ahrps.org ... or ... monte@stinkwaterwells.com
Detectors: Vista 'X' / Vanquish 540 / CoRe, Relic & Simplex + / Bandido II µMAX & Silver Sabre µMAX / XLT / ORX
Pinpointers: Pulse-Dive .. Headphones: Killer B's 'Hornet' & 'Wasp' ... White's 'Pro Star'
Note: Detectors are listed alphabetically by Brand. Models are chosen based on search site conditions.
*** All working well today to make memories for tomorrow. ***
Subject Author Views Posted

Tesoro Discrimination

Druid 524 November 08, 2018 09:41AM

►Warning -- this is Lengthy: Tesoro Discrimination Acceptance Ranges ... from Pre-ED to the present.

Monte 826 November 09, 2018 10:31AM

Re: ►Warning -- this is Lengthy: Tesoro Discrimination Acceptance Ranges ... from Pre-ED to the present.

Timbertodd 319 November 09, 2018 03:50PM

Re: ►Warning -- this is Lengthy: Tesoro Discrimination Acceptance Ranges ... from Pre-ED to the present.

Druid 348 November 09, 2018 12:11PM

My 2¢ worth of advice on the Outlawsmiling bouncing smiley

Hombre 435 November 09, 2018 03:57PM

Re: My 2¢ worth of advice on the Outlawsmiling bouncing smiley

Druid 340 November 09, 2018 05:27PM

Re: Tesoro Discrimination

jmaryt 354 November 08, 2018 07:26PM

Re: Tesoro Discrimination

jmaryt 352 November 08, 2018 08:01PM

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