Tuning for different coils?

[KennyD]

I have read that using a tesoro coil other than the coil that came with the machine requires tuning to that machine.
Why the Heck would Tesoro sell coils and then require that you send the machine in to them for tuning?
Does anyone really KNOW the answer to this?

 

[john67]

the coils should be fine especially on a machine with manual ground balance. I have one machine with preset ground balance and have not had an issue running different coils on it either. not sure about non Tesoro coils.

 

[BarberBill]

I called Tesoro some years ago about this issue. I was told that for the optimum performance with a given coil that is the ideal thing to do. However, many times you can swap coils and the swap works just fine, even better if you have manual GB. I've swapped coils of different sizes often on preset and gb machines and always had satisfactory performance so I'd suggest you try the combination you have in mind first. Then, if the performance seems off, compared to what you would expect, send it in to be tuned. Only problem I've encountered to date is with the 9X12 spider on a DeLeon chattering in my soil.
BB

 

[RLOH]

Kenny, unfortunately Tesoro Id detectors(Deleon-Cortes) will probably not work correctly with any coil but the coil that came with that particular detector. These two detectors have factory preset ground balance in disc mode. I had a Cortes and tried a 7 inch widescan and the ID was way off, not even close. I was afraid to send it back to Tesoro for fear that if the 7 inch widescan was tuned to the Cortes, then the 8x9 concentric would be off. I never had any problem with a Vaquero or Tejon when I switched coils. Both of these detectors have manual ground balance. Maybe others have not had these type of problems and all the coils would work correctly, but I would always wonder if they were tuned right in the middle. If this is the case, how would anyone really know if their machine was up to it's potential. I always check the preset ground balance in all of the sites I hunt. I do this by using all metal with a slight threshold. I slowly pump the coil up and down over clean ground. If the threshold is negative or positive, I will immediately know the detector will suffer and I get very poor performance.

 

[Monte]

I have read that using a tesoro coil other than the coil that came with the machine requires tuning to that machine.
Why the Heck would Tesoro sell coils and then require that you send the machine in to them for tuning?
Does anyone really KNOW the answer to this?

Yes, I KNOW the answer, and unless a particular search coil has a flaw or is out-of-spec and needs repair or replacement, Tesoro doesn't "tune the search coil" per se. The search coil is part of the overall circuitry design and what it calls for is making sure the metal detector has a proper Ground Balance with a search coil to be functional.

If you have a model that has a manual GB, AND if the Discriminate mode is tied in with that GB setting, then you don't have to send the detector in with a proper-functioning, in-spec search coil. You simply adjust the Ground Balance with the search coil you want to use for peak performance for the mineralized ground you are searching. It could be any of the Bandido series, the Pantera, the Eldorado, Euro Sabre, Vaquero, Tejón, or any other Tesoro models with the Disc. mode tied in with the All Metal mode GB circuitry .

If you have a model with an internally preset trimmer for Ground Balance for the Discriminate mode, such as with the Cortés, DeLeón, Silver Sabre series or Silver µMAX, Golden Sabre II, or all the many "turn-on-and-go" models [size=small](meaning they have a pre-set GB and are ready to go)[/size], then you have to have a GB setting that is 'functional' with the search coil you are using.

Tesoro models are usually shipped with the search coil they were checked out with and 'calibrated' with a proper, functional GB setting. If you change search coils, and if the coil is of sound quality and within performance and tuning specifications, then you 'might' have a GB setting that is functional. If you DO NOT, then BOTH the detector and coil have to be 'tuned' or 'calibrated' at the factory. Not necessary with a model that you have manual GB control of [size=small](that excludes the Cortés, DeLeón and Lobo ST)[/size] that has the Disc. mode teid in to reference off the All Metal mode's GB adjustment.

In mild ground that doesn't vary much, most models can handle coil swaps just fine. They still might not have an ideal GB setting, but it would be useable and not cause falsing. However, if you swap a standard supplied coil for any other, and the ground mineral environment is more extreme, such as much more mineralized than how the stock coil was tuned/GB'ed with that model, then the accessory coil might be off just enough to cause falsing from being too negative.

If you had a model such as a Silver Sabre [size=small]micro[/size]MAX or a Conquistador [size=small]micro[/size]MAX, and you had a stock 8" or 8X9 coil lis a 6" coil or 7" coil and maybe a 10X12 Concentric or 10X12 DD coil, and one or two of those coils caused falsing, then to have the internal GB adjusted [size=small](aka 'calibrated' or 'tuned')[/size] then you would need to send the detector and ALL of the search coils to Tesoro. They would make sure each coil is 'on spec' and not defective, then use all three search coils to find a GB trimmer adjustment that would allow all of the coils to work w/o falsing. That might result in one or two coins having a somewhat positive Ground Balance, to assure the 3rd was functional and didn't cause falsing.

I prefer to own and use a Tesoro that features a manual GB control, such as a Bandido II or Bandido II µMAX so that I can swap coils and make sure I have a proper 'tuning' for the site I am going to search. However, I do have my "turn-on-and-go" Silver Sabre [size=small]micro[/size]MAX which I grab very often for a lot of 'flash money' urban Coin Hunting, but I don't have any problems with it. I like the thin-profile 6" coil best for trashy sites, so I keep that coil mounted to my detector full-time, and I tweaked the internal GB trimmer for that coil to provide very functional performance in severe mineralization and not false or misbehave wherever I hunt. I don't have any other search coil for it as I use only the 6" Concentric.

So it really depends upon the particular Tesoro model you use. If it is not one of the three models I mentioned and it has an external GB control, then you are the one doing to 'tuning' by adjusting for a functional Ground Balance. If you use a preset model, then depending upon the varied mineralization you hunt and the particular coil you want to mount, there is the chance it might require you to 'tune' or adjust the internal GB trimmer for peak performance ... OR ... send the detector and all coils to the factory and let them do the 'calibration' - 'tuning' - tweak the GB trimmer.

Monte

 

[KennyD]

Thank you guys for the informative replies. Very helpful.

 

[BarberBill]

I have to respond to the statement "that the Deleon and Cortez will only work with the original coils". Not true in my expereince. I have both and have used the 8" donut, the 7" concentric and the 5.75 Concentric on them with no problem.
BB

 

[jld66]

Yeah, I have an older Vaquero that came with the 9x8. bought the 11x8 and it ground balances in a different spot. think its worth the extra money to have the manual GB. that way all the bases are covered.

 

[amberjack]

I think Tesoro say that because Jack said they have too and so its Tesoro folk law now

AJ

 

[jld66]

I think Tesoro say that because Jack said they have too and so its Tesoro folk law now

AJ

What? Manual GB is always better than pre-set, anyone will tell you that. Folk lore (folk law)? haha

 

[Walknstik]

I have a Troy Shadow X2 and everytime I would switch to a different size coil I could hear a change in my ground balance setting. This area of Texas has mild ground and once I reset GB trim-pot on the X2 to one particular coil I'm "good to go" for this area. Decided long ago just to leave the Troy Super 7" coil on the X2... if I wanted to use another size or type of coil I would take the original Bandido with the 10-turn manual GB adjustment.

I'm really PICKY about my GB setting and is the reason I like to have an audible threshold based All-Metal mode so I can keep tabs on the ground conditions! Most people can use preset units without problems for the most part but for the "picky" folks I prefer a manual GB.

 

[BarberBill]

I've got a mix of both preset and manual or auto ground machines. MOST of the time in the soil I usually detect, they all work reasonably well. If or when I run into ground that isn't so sweet, I grab one of the adjustable detectors.
BB