Sometimes we will read that a Tesoro and coils have been sent to the Tesoro factory service department to be '
calibrated.' This is just another term that can refer to having the metal detector '
tuned' for the search coil and there are a few things to consider here, and I'll try to explain in my answers to your questions below.
Herb Jones said:
i have a few tesoros...but they were all used when i purchased them.
I have been using Tesoro's for almost 34 years now, acquiring some brand new and most of them used. I always try to use caution when buying a used detector of any make from anyone to feel comfortable that the unit is in good working order, has the 'standard' coil it would have been sold with, and whenever possible, I like to do some hands-on handling first to check them out. In this day and age, so many are sold via internet sales we don't get the opportunity to do that.
I very seldom have bought or traded for a Tesoro that needed factory service unless it had a broken part. I also try to check any Tesoro with an assortment of search coils I have on-hand for it to be certain the search coils seem to be working properly, and also to make sure the detector and coil are '
calibrated' or '
tuned' for peak performance. Here are two things to be aware of:
1.. In order to make sure the detector and search coil can provide you with peak performance, the search coil must be "in spec," and that means that there is no damage or defect with the coil internally and that the coil itself is within the proper tolerance and designed specifications. If so, then you can continue checking for functional performance.
NOTE: If a search coil does not check out correctly to be in serviceable condition, there's no need to continue with it until it is repaired or replaced.
2.. A proper '
calibration' or '
tuning' refers to having the most functional or proper Ground Balance setting. With Tesoro models this falls into one of two categories of Ground Balance design:
• Manual Ground Balanced models: Observing the three Tesoro models you have listed in your signature, you have two models that provide
you, the operator, the ability to manually adjust the Ground Balance in an All Metal mode with the Vaquero and original Eldorado, and with these models the Discriminate mode has a GB reference off the All Metal mode's GB setting. Thus, if you have a properly functioning search coil, or set of search coils, then you can easily do the proper GB for any of the coils functional on that model. Once the GB is properly adjusted, you have the best '
calibration' or '
tuning' for that detector and coil.
You then have the opportunity to change to any other size, shape or type of coil that is designed for that model and adjust the Ground Balance for best performance afield.
• Factory Present Ground Balanced models: All Tesoro models that rely on an internally preset Disc. mode GB are supplied with a standard coil they have already been '
tuned' or '
calibrated' with. At that point, the specific detector model, in this case your Lobo SuperTRAQ, has only had a proper GB '
calibration' or '
tuning' adjustment for that one specific search coil. Can you use other search coils designed for that particular model? Yes. Will all of them work properly? That is unknown, unless you have had that specific detector and those specific coils all checked out and the internal GB then '
tuned' / '
calibrated' to at least be functional with all the assigned search coils.
Once all coils a person has for a factory preset model have been checked and the internal GB trimmer tweaked to a workable setting for them to be functional, they might be anywhere from a nearly perfect or 'spot-on' GB setting to a somewhat more 'positive' GB setting simply due to the variance in tolerances between each of the search coils. This is one reason why I personally prefer to assign one search coil, only, to any factory preset model in my arsenal, and make sure I have tweaked the GB for that unit and that one specific search coil so that it is '
tuned' / '
calibrated' to handle the more challenging ground mineral environments I am likely to work it at.
That's why my personal preference is to keep one or more Tesoro's in my detector battery that have a Manual GB control so that I am able to set any search coil I mount to them for the absolute peak performance achievable, in any ground mineral condition. In my case, the more versatile and controllable models I own and use are my manually Ground Balanced Bandido II [size=small]micro[/size]MAX and Vaquero.
Herb Jones said:
if i sent them to the factory for a check up, should i send along the coils I use on them, and specify which coils are primarily used, and what type if hunting I am doing?
Yes, I would encourage you to send them ALL of the search coils you have, especially since you acquired them used and don't know if they have endured abuse from abrupt banging, or if they are not the actually coil supplied with that model.
No, they don't need to know what type of hunting you are doing and any type of hunting van take place in a wide-range of ground mineral environments. You can control that with the original Eldorado if the coils are in very good functional condition, but the Lobo ST coils ought to be checked and then it needs to have the internal GB '
tuned' for the coils you have for it.
They don't need to know which coils you will primarily use on a model if you change coils, because you can adjust for them with the Eldorado, or they will have the GB set to compensate for any variances in the assortment of coils you send them for it.
Herb Jones said:
would they tune for a specific coil or for a range if coils?
They should first
• 1.. check all of the search coils to ensure that they are all 'in-spec' and functioning properly. Then using the preset Lobo ST and all of the search coils you have for it then can
• 2.. adjust the internal trimmer to a setting that will be workable with all of the search coils. One might be close to 'spot-on' and others might be just
slightly positive or negative of that setting, but still functioning OK without any falsing over more challenging ground mineral conditions.
Herb Jones said:
do the coils need to be checked as well?
Yes, to make sure they are all 'in-spec.'
Herb Jones said:
whats a typical turn around time?
In the past 6-7 months I have had an original bandido [size=small]
(broken battery clip & wire)[/size], Bandido II µMAX [size=small]
(broken Threshold pot shaft housing)[/size], and Vaquero [size=small]
(brand new but in for a high-tone modification)[/size] delivered back to me within 2 weeks from the date I sent them in. Note, however, that I always ship things off Priority Mail to expedite delivery time.
Herb Jones said:
metal eldorado with 10 turn ground balance and stock football shaped coil
The original Eldorado, produced from 11/'86 to 4/'91, was supplied with a thicker-body round 8½" Double-D [size=small]
(Tesoro called them Wide-Scan)[/size]. I was a Tesoro Dealer back then and I can not ever remember an elliptical [size=small]
("football shaped")[/size] search coil ever being a 'stock' or 'standard' coil. Buying it used it was likely supplied with a different coil than it came standard with.
This is another reason to make sure all coils go back as it is possible it is not the proper search coil for that detector, and I would even question of it was serviceable and 'in-specification,' which is something they will check for you.
If you have any specific questions, I would welcome a PM or an e-mail. My address is shown below.
Monte
