Tesoro Relic Coils

[david bull]

I just picked up a Tesoro Cortes in mint condition but the previous owner was strictly a coinshooter.The only coil with the detector was a Tesoro 7” concentric.My preferred hunting is for civil war relics.Any recommendation for a larger coil?I have a NEL Tornado on my F75 that works very well.Has anyone had any experience using this coil on a Tesoro?Thanks!

 

[REVIER]

I just picked up a Tesoro Cortes in mint condition but the previous owner was strictly a coinshooter.The only coil with the detector was a Tesoro 7” concentric.My preferred hunting is for civil war relics.Any recommendation for a larger coil?I have a NEL Tornado on my F75 that works very well.Has anyone had any experience using this coil on a Tesoro?Thanks!

My Nel coils work great on my Fishers, I assume if you can get the correct one to match the Cortes it would do well also.
Probably a bigger DD type would work pretty good, widescan is what Tesoro called them.
I have read a few posts about the Cortes, seems to be a great relic machine...likes to find iron.
A few mentioned one issue, though, when changing coils some had to send theirs into Tesoro to calibrate them correctly, not all but some.
They mentioned some targets weren't being picked up correctly, not sure why, with the GB feature most times this isn't necessary when changing coils but these guys took advantage of the free coil calibration service Tesoro used to provide........when they were still around.

 

[Monte]

I just picked up a Tesoro Cortes in mint condition but the previous owner was strictly a coinshooter.The only coil with the detector was a Tesoro 7” concentric.My preferred hunting is for civil war relics.Any recommendation for a larger coil?I have a NEL Tornado on my F75 that works very well.Has anyone had any experience using this coil on a Tesoro?Thanks!

The Cortés, even though not one of my favorite Tesoro models, can serve you well for Relic hunting as long as the search coil works well and the detector/coil GB is functional. There's one of the issues with the Cortés, it relies on an internal GB trimmer. Also, it didn't come standard with a 7" search coil so a question would be was that particular coil 'calibrated' (a Tesoro term for adjusting the Ground balance for all available search coils) done for that 7" Concentric coil? I was a Tesoro Delmer back when the Cortés was introduced and took one out to evaluate afield using the stock Concentric coil, a white Tesoro 7", Concentric, a black 7" Concentric for the Shadow X2, a larger 10" coil and the CleanSweep DD Ia customer had ordered.

At the time I kept a few coins in my pocket all-the-time, kind of for 'good luck' but mainly to evaluate a lot of detectors that relied n an internally preset GB. Note here, if you didn't already know, that most Tesoro Discriminators were designed so the Disc. mode references off the All Metal mode GB setting, and, by design, had a somewhat positive off-set from that GB to help eliminate falsing should you be searching in a very mineralized ground environment. In other works., if the GB was done at point A and at point B it was more mineralized, the Disc. mode would generally be positive enough to not false off the bad ground. However, there can be a trad-off to that design concept, and that is if the GB setting is too high, the Disc. mode's GB reference would be off-set a bit too positive and that can impact the detection of higher-conductive targets.

Back to checking out the new Cortés: I was in a rather mineralized environment in western Oregon and, using all of the search coils I had available, including the stock coil, I discovered that the stock coil appeared to work properly. No falsing and no loss of response on test targets. But one of the coils resulted in a too-positive GB in the Disc. mode, and Disc. was always set at the minimum position, and being too positive it didn't respond to my 1921 Morgan Silver Dollar i carried. But other problems arose with two of the coils, especially the 7" Shadow X2 Concentric coil I wanted to use for Coin Hunting, because both of those coils were resulting in a too negative GB and I had a lot of falsing when sweeping over the ground, dips, bumps, rocks, etc.

The Cortés needed to have a functional 'calibration' or GB trimmer setting that would handle all the coils I wanted to use. Well, I didn't want the CleanSweep, but did want the 7" Concentric and 10" to work, but that would have called for a slight increase of the GB trimmer to be just a little more positive to eliminate the falsing. I sent it to Tesoro and communicated by phone and e-mail with James when he was there. They fixed the other issue, but didn't get the GB trimmed up right when I got it and all the search coils back.

So I went in myself, found the correct trimmer, and tweaked the GB o that the 3 coils that I wanted to use were all gong to work OK in bad ground, and not be too positive in the Disc. mod to reject a Silver Dollar. Search coils are a part of functioning circuitry in all or most Tesoro models so it is important to make sure all adjustments are done for each specific search coil. I recall in the mid-'90s when a customer bought a Tesoro with preset GB and it worked fine .... with the stock 8" Concentric coil. They wanted a smaller 7" coil and bought one from a club member. The detector falsed like crazy. So we tried two other 7" coils I had around, one on a Bandido I used and another new one. One of the two still falsed a lot but the other 7" coil was much quieter when worked over some mineralized ground where we were in Utah. So I swapped them 7" coils for the better-working one, and then I tweaked the GB trimmer for them so that BOTH the stock 8" and the new 7" Concentric coils would both be function.

In my personal Detector Outfit I have a couple of my all-time favorite Tesoro's. One is a preset GB model that ONLY uses a 6" Concentric coil I keep mounted full time. The other is a manual GB'd model that I also keep a 6" mounted to, but if and when I want to use a different search coil on a Tesoro, that's the one I grab because once there is any coil change, I have control over the GB adjustment and am able to 'calibrate' the proper GB setting for the detector with that coil.

Just a heads-up about using a Tesoro and an alert for switching search coils to. Oh, one more comment. I have owned and used just about every Tesoro model and checked out a lot of the available Tesoro coils. Many of those models just did not work well with a DD coil, especially when Relic Hunting the very iron contaminated ghost towns I like to visit. Concentric coil are usually the better-performing coils all-around.

Monte

 

[david bull]

I’m aware that the ground balance only works in the all metal mode and that the discrimination mode uses a fixed/preset ground balance.Could different coils be manually ground balanced and used in all metal?I’m not sure but I think the tid works in both modes.As always,I appreciate and respect your advice.Thanks for the input.

 

[Monte]

I’m aware that the ground balance only works in the all metal mode and that the discrimination mode uses a fixed/preset ground balance.Could different coils be manually ground balanced and used in all metal?I’m not sure but I think the tid works in both modes.As always,I appreciate and respect your advice.Thanks for the input.

In theory, Yes, the manual GB will adjust the proper GB setting in All Metal mode, so if that's the mode you'll use then all is well. Yes, different coils can be used in All Metal and not be an issue. Now, to the Target ID. When I am Relic Hunting, 95% of the time I am going by audio only. Too much ferrous debris, and non-ferrous, that cause good-target masking and that means visual TID is close to useless. Also, with most detectors, if in relatively clean environments where there is no nearby trash that would effect the keeper-target response, they often experience degraded visual ID performance / accuracy as the ground gets bad and / or the targets get deeper or at an odd position to the coil.

I am not certain how good the TID is, or how it is associated between the All Metal and Discriminate modes on that detector. I know some people enjoy certain models that I don't and they work fine for them, and that's good. All I know is the one I got, intending it to be a keeper in my own outfit, frustrated me. Tesoro didn't fix it well, and after I did it didn't false and it didn't reject silver Dollars with a functional internal GB for the Disc. mode, but I wasn't thrilled with the Target ID, either, compared with several other brands models I used. I had ordered in two other Cortés models for customers, and after we were certain they didn't false or have high-conductive target detection, they still didn't work well enough for those two experienced guys who parted with them within six months or so. Poor TID on targets at 5" or deeper was one of the reasons.

Monte

 

[david bull]

Most of my detecting is in open fields where everything non-ferrous gets dug.Targets that TID at 60-65 out of the ground struggle to achieve a 10-20 TID at 6” in our dirt.I hunt either all metal or one tone discriminate with disc set at 5 or below with my F75 and dig anything that tries to rise above 10 TID.With my beep/dig Tesoros,any solid round tone gets dug.These methods have proven quite successful in some ”hunted out” sites.