Possibly, and possibly not. It all depends upon how well the particular unit you have was initially 'calibrated' [size=small]
(meaning Ground Balanced)[/size] to match the standard coil supplied with it, and if that coil has been swapped for a different search coil or if you plan to use two or more search coils with it.
thump7 said:
I don't see what the big deal is.
Well, many Hobbyists don't really understand what Ground Balance is or the benefits or detriments of having a GB adjustment that is too positive or too negative.
thump7 said:
My first machine was a silver umax and it struggled in a couple spots where either the sand was wet or the dirt was red and mineralized, other than that it always worked great.
The Silver µMAX started in production in June of 2001 so the most experience you have had with detectors in this great sport is now 16 years, IF you started at that time. I have found that quite a few 'turn-on-and-go' [size=small]
(meaning factory preset Ground Balance)[/size] models from other detector makers as well as both the Tesoro [size=small]micro[/size]MAX and other Tesoro detectors, can have 'noise' or falsing issues when used around wet salt beaches or in some extreme mineralized ground environments, but those are usually two different extremes.
Responding or beeping on or over wet salt sand or water puddles is caused, partly, by the substance being a low-conductive 'target' due to the wetted saltwater. This can also occur in some alkali desert environments after a heavy soaking of rain from a thunderstorm, causing the alkaline or salty ground make-up to be well wetted to create a lower-conductive medium. That can usually be dealt with by increaseing the Discrimination to go beyond ferrous target rejection into a zone to knock out very thin and lower-conductive foils,
and wetted salts. Ground Balance can also be a factor to consider due to the iron mineralization of the effected environmental conditions.
So other than areas/conditions where the Silver µMAX didn't seem to work well, it did seem to work okay. But the question still remains, how well was it working in other conditions where the internal GB setting happened to be
too positive? With many makes and models, especially most Tesoro Discriminators, a GB setting in a true Threshold-based All Metal mode can be close to 'spot-on' but a check of the Discriminate mode would have the GB more positive than that All Metal mode. That is due to a circuitry design concept whereby Jack Gifford used a somewhat positive offset reference for the Disc. mode GB from the true All Metal mode GB setting which eliminated falsing in the Discriminate mode in case the detector was exposed to more mineralized ground than initially adjusted for in All Metal mode. For the most part, the preset GB models from Tesoro have generally been reliable for most 'average' Hobbyists in most 'average' hunting conditions.
However, I can assure you that there can be issues at times with a preset Tesoro GB that are easily remedied when the coil is attached to a model that provides Ground Balancing in the search mode used. I have experienced it on personal models, new models used for display and demonstration, and with models others have brought to one of my seminars. No, not all of them, but some units in some conditions. Falsing or other detrimental behavior can usually be taken care of with a GB adjustment for a specific coil in each search mode to reach a 'functional' GB setting.
thump7 said:
When I got the vaquero, I thought all my problems would be solved only to find that it struggles in all the same ways the silver umax did. I've used about a dozen med-low end machines since then and tried them on different types of dirt with similar results.
If you used most typical detectors offered on the market over salt water beaches, in the surf, a very wet beach, or sweeping the coil over pools of salt water, you will likely get similar results. If a detector has a functional Ground Balance, and sometimes a wee bit of low-end Discrimination if necessary, there won't be the same types of problems.
If you move from your 'average' local area soil to a vastly different ground, be it 'red dirt' or pea gravel, dense black sand pockets or a lot of broken-up 'hot' rocks or 'cold rocks', and you are using a 'turn-on-and-go' detector without an external adjustment to correct the Ground Balance for a site, of if the Discriminate adjustment range doesn't cover your needs, then yes, you are going to run the risk of having problems afield. If you have a detector with manual or automated GB and functional adjustments, you can control the site challenges yourself.
thump7 said:
I also had a 10x12 concentric coil mounted on the silver almost full time, it ran like a champ. I sold that coil with that machine years ago, so recently I bought another and put it on the Cortes. It works great, it is a little sensitive when bumped but I think that is just how that coil works. I can run sensitivity just as high as I could with stock coil before I get any chatter, which is well into the red, Great depth too.
Some Tesoro models can provide increased 'depth of detection' over other Tesoro models, especially compared with some older offerings, even though some are still on my all-time favorite Tesoro list.
I have had a lot of experience with my own Tesoro models, also with customer's units since I was a Tesoro Dealer from July of '83 until November of '04, plus many I have assisted on detecting outings, club get-togethers or just being contacts by phone, e-mail or in person. Sometimes it has just been assisting consumers with the 'basics' to get to know their detector better. Often it included helping people learn what Ground balance is, and how to adjust the manual GB or internal trimmer control for either the Threshold-based All Metal mode, or tweak the Ground Balance for best performance in the silent-search motion-based Discriminate mode.
A good share of those 'instruction sessions' came about when I was helping them get the best GB adjustment for an accessory or non-stock search coil. The reason was the preset GB was off, sometimes too positive but often too negative a GB causing falsing and impaired performance in tough bad-ground scenarios and their preset ground rejection was in need of adjustment for the to handle higher mineralized ground. Or, just to handle the ground where their stock 8" coil was working 'OK' but the accessory coil didn't..
In '92 I was working on a USFS archaeological project with volunteers and someone had a new Tesoro Silver Sabre II with was working fine. Due to the trash and the brushier areas we were asked to search, they wanted to use a 7" Concentric coil like I used on most of my Tesoro's and two others also used them on their units. I was asked to help because their Silver Sabre II was quite noisy over some of the rockier or gravel/dirt areas. Reason? The GB was too negative and the detector produced false signals or 'beeps' when swept over the ground mixtures or when the coil was lifted away from the ground in the Discriminate mode.
For a quick-fix, I hoped, I just swapped that new 7" coil they bought for an identical 7" Concentric coil. Same results, just a little better but still too negative. I then tried a different 7" coil and it, too, didn't work right. I swapped my lower-rod w/7" Concentric and it was close to a functional GB, but still just slightly negative. So we went back to the one new coil I had that showed the Silver Sabre II to be close but off slightly, and since they only planned on using the standard 8" and new 7" Concentric coils, I used both of those coils when I opened up her Silver Sabre II to tweak the internal trimmer for a functional GB setting to handle using either search coil
In that example, manually adjusting the preset GB WAS a 'big deal' and it was also an example to them why I prefer a manually Ground Balanced Tesoro models over a preset unit
IF I planned to change search coils, or select a very challenging site to hunt. With my Cortés, after they were introduced, I wanted to check it out with an assortment of search coils I had in my search coil display for sale, and also check out how the Cortés performed.
With the supplied search coil the Cortés worked OK, and depth of detection was notably a bit better than an 'average' Tesoro model in the grassy parks. Since I hunt trashier sites I have preferred smaller-than-stock coils most of the time, but also wanted to check out a CleanSweep, 10X12, 7" Concentric and a 7" Wide-Scan, plus a thin-profile Super 7 Inch coil off a Troy Custom Shadow X2 that was made by Tesoro..
In the Threshold-based All Metal mode I was able to adjust the GB for each coil and noticed there was a marked difference in adjustment to achieve a functional setting for them all. In the silent-search Discriminate mode, only the standard coil and one of the Tesoro 7" coils worked on the Cortés w/o falsing. All of the other search coils would false, some more significantly than others, if I swept over a depression or void, or lifted the search coil away from the ground, and that indicated I had a negative Ground Balance setting in that mode for the coil that was mounted. The factory 'preset' GB was not functional with all the search coils, especially the one I wanted to use the most which was the 7" Shadow X2 coil.
I opened the Cortés up and used each of the search coils I had available, plus the 7" coils I had on my own original Bandido, Bandido II µMAX and new Eldorado. That was quite an array of coils and some of them worked with one small tweak of the GB setting, but my goal was to ensure that ALL of the search coils could be used on that specific Cortés without falsing. One I accomplished that tweaking session of the internal GB trimmer, I could mount any available search coil to that particular preset GB Cortés and they would work satisfactorily [size=small]
(meaning they worked w/o falsing, but not at a peak GB setting)[/size] for hunting in my average grassy parks and yards, and could even work in very mineralized black sand volleyball courts, pea gravel and dark-sand playgrounds and other challenging mineralized sites.
I kept the 7" Shadow X2 coil mounted for my personal use, and it just happened to be very close to a best GB setting in the Disc. mode. With two of the search coils in that assortment, for the Cortés to handle ALL of the coils with one preset adjustment, those two coils were at an extreme that left them with a very positive GB and that meant a loss in detection depth, especially with some higher-conductive test samples, those being a silver Walking Liberty Half-Dollar and a 1904 Silver Dollar.
Most folks would never know the GB setting was too positive because they don't know how to tweak the GB of any Tesoro in a silent-search Disc. mode to verify a peak setting or not, therefore would presume it worked fine simply because they didn't hear any falsing.
thump7 said:
My point is, no ground balance was needed to make this coil work fine, same as my first experience with the silver.
By the description I just gave, all you knew was that the search coil worked. However, all that mean was that the GB setting was not too negative so as to cause falsing. But working only meant it had a peak performance GB setting, or it had a more positive GB setting, and unless you knew the peak setting for that coil and how far off that setting in the positive direction it was adjusted for, then you didn't know if it was a spot-on GB adjustment, slightly positive, or perhaps very positive to the point you could be losing detection ability and depth on higher-conductive targets.
With an externally positioned manual GB control, then it would be very easy to adjust any model for the best setting for each specific search coil and not rely of a pre-determined setting for one coil that just happened to let a different coil be used w/o falsing.
thump7 said:
My conclusion is; other than fidgeting and fine tuning ground balance is over rated, if the ground is so mineralized that the machine can't get any depth, a ground balance isn't gonna help much either. Please share your thoughts, if you disagree I want to know why.
Well, you are incorrect in that statement because good ground to bad ground, you are able to attain peak performance and gain the best achievable depth-of-detection when you have direct control of the Ground Balance adjustment for that particular search coil and in each specific search mode.
This is why I prefer to use my
manually Ground Balanced Vaquero, Bandido II µMAX and first-release Bandido most often to best handle any soil condition I encounter and do so with any search coil I have mounted to them. My turn-on-and-go Silver Sabre µMAX uses ONLYT the thin-profile 6" Concentric coil I have mounted on it, and I tweak the internal GB trimmer to be able to handle the mineralization extremes I encounter for the bulk of my detecting.
Just my views for owning and using a lot of Tesoro's because I know they work well ... when properly adjusted.
Monte
