Jump to content
Sign in to follow this  
DukeBoxer

Ground Balance Issue And (my) Solution With The Tesoro Mojave

Recommended Posts

So I have a Tesoro Mojave that I love, it made me put the "all mighty" AT Pro down and never pick it up again. But ever since I got it I couldn't use it on the "Low" ground condition setting because it would false like crazy. I finally decided to have a serious look around and see if anyone had this problem and had fixed it and I couldn't find anything. I posted on treasurenet to see if anyone could help with at least some knowledge of the trim pots on the circuit board but i didn't get much help. Then I remembered about a website I saw a while ago, TreasureLinx, that had some diagrams of Tesoro mods on it. So I emailed Sven, the owner and asked if he could help out. He told me which trim pot controlled the ground balance and I fixed the problem, at least so far I think it's fixed. I'm going to copy and paste the posts I made to treasurenet and the email to Sven here...

 

(POST 1)

Hey all. I've searched around google but I can't really find any information about this. I bought a Mojave on eBay a year or two ago and I love it. I found my first and best gold ring with it and i even ditched my AT Pro in favor of it. The problem is it's always been pretty hot and falsed a lot in the low setting of the GB. In southern CT I had to run it on the high ground balance even though I'm pretty sure the ground there isn't that mineralized. I love in Costa Rica now and the few times I've taken it out it likes to false on the high GB setting and the low is basically unusable.

I've tuned the ground balance on my compadre that ran hot when I got it too but from what I can see there's no GB potentiometer screw on the Mojave. Does anyone know of anything I can do tune it a bit so it doesn't run so hot?

(EMAIL TO SVEN)

Hi, my name is Josh. I have a Tesoro Mojave that runs hot in high ground phase mode and I was wondering if you knew if either of the trim pots on the board are for adjusting the ground balance? I'm trying to ask on treasurenet and on the Facebook Tesoro group but I'm pretty sure it was you who put a manual ground balance on your Mojave.

I've adjusted my compadre because when I got it it would false on some basalt rocks and now it runs perfectly quiet. But the Mojave has been chattery since I got it. Here's a picture of the board, I don't think you need it but I marked the two trim pots and the two wires coming from the ground phase toggle. Thanks!

 

(EMAIL BACK FROM SVEN)

Hi, one towards the PCB center should be GB pot, the other will be disc bias- don't touch it.
Tom has reworked his Mojave with full mods, contact him thru Findmall https://www.findmall.com/profile.php?56,1260
Sven

 

(EXPLANATION OF MY SOLUTION ON TNET)

Ok I fixed this one too (I'm referring to the almost same problem I had with the Compadre that is documented on this forum also). I emailed Sven from treasurelinx, hoping he'd see the email and get back to me at some point in the next couple weeks...it was less than 12 hours before I had a reply. I asked him if he knew which trim pot, if any, controlled the ground balance. He informed me it was the one on the left, the innermost one that did. The one on the outside controls the discrimination and should not be touched. Here's what I did.

I opened up the control box and exposed the board. I made sure the disc was set to the lowest position in iron (basically no disc), the sensitivity was on 4 and the ground condition was on low. I took the coil and pumped it at the ground and it falsed. I then turned the trimmer all the way CLOCKWISE until it wouldn't turn any more. I did this very very easily and lightly. If you attempt this remember, easily and lightly. I then pumped the coil to the ground to make sure it wasn't falseing still and it wasn't. Then I started turning it back COUNTER CLOCKWISE a tiny bit at a time until it started to false and then turned it slightly back CLOCKWISE to where it didn't false any more. Remember, the movements are slight when turning the trimmer. 

I also noticed that when I touched the yellow wire coming from the ground condition toggle, it made the machine false also. Knowing why and being able to fix it is probably beyond my knowledge and comfort zone so I made sure that when I put it back together it was snug and didn't move. I'm guessing some of the falseing was for that wire and other falseing was from the ground balance being off.

Again, this was the solution to my problem. It might not be the same for everyone but it worked for me. I hope this helps at least one person with the same problem since I couldn't find a solution for it myself, or even a good picture of the board

 

Here are some pictures of the Mojave board for reference

IMG_20190514_064525-01.thumb.jpg.f30145e4744597b98f36d97cfc43ba20.jpg

 

840011430.thumb.png.e2b600f11fed87460c45f3195ab076f4.png

  • Like 7

Share this post


Link to post
Share on other sites

Great information, thanks for taking the time to do such a detailed post. 👍

Share this post


Link to post
Share on other sites

Just curious as to what number your ATpro ground balances at??  Probably just more mineralized soil in your area led to using “high” ground setting.   Mojave is my go to travel machine and depending on location have used both settings.  

Tesoros are great fun in the tweaking and modding department.  I have a coupke frankensteined compadres that are super fun to use in certain applications.  The only problem I see with adjusting the GB on Mojave is giving up the more neutral “low” ground setting.  If you have ground that suits it you will definitely get a bit more depth. But in hotter ground your solution will probably serve you better.  

Share this post


Link to post
Share on other sites

Thanks Steve, I've said it before and I'll say it again, I hate looking for solutions for problems and seeing the op say, ok I fixed it, thanks for the help, and there's zero explanation on how it was done. 

 

Noah, I think you may have given me a few pointers before with my compadre when I was having a problem with it falseing on basalt rocks. My AT Pro ground balanced around maybe 80-87 when I was in CT. From what I remember I think that was the preset ground balance for normal non mineralized ground. I'm in Costa Rica now and I don't have that machine any more but I'll see what my equinox balances at in a little bit. I think even from when I got it before I adjusted it, it was still a little off. 

  • Like 1

Share this post


Link to post
Share on other sites

Touching wires inside I would expect would sound off. My Tejon can pick up my hand when I run it past the coil. They are sensitive machines. 

You could drop the sensitivity down if needed. Does the Mojave have a ground tracking like the Lobo or is it just a generic high or low switch?

The few times I ran my Tejon at the beach I did have to drop sensitivity down to gb it as I got close to the water but was able to nudge it back up to close to full after. This worked fairly well but there were areas I simply couldn't run it at all. The AT Pro I have was much more forgiving in crap soil and beach.

Share this post


Link to post
Share on other sites
4 hours ago, DukeBoxer said:

Ok, the equinox balances at 7-9 in my front yard where I balanced the Moj

Share this post


Link to post
Share on other sites
4 hours ago, DukeBoxer said:

Thanks Steve, I've said it before and I'll say it again, I hate looking for solutions for problems and seeing the op say, ok I fixed it, thanks for the help, and there's zero explanation on how it was done. 

 

Noah, I think you may have given me a few pointers before with my compadre when I was having a problem with it falseing on basalt rocks. My AT Pro ground balanced around maybe 80-87 when I was in CT. From what I remember I think that was the preset ground balance for normal non mineralized ground. I'm in Costa Rica now and I don't have that machine any more but I'll see what my equinox balances at in a little bit. I think even from when I got it before I adjusted it, it was still a little off. 

Probably hot ground down there in CR. Volcanic basalt everywhere I would imagine.  

Thats the fun part of Tesoros or other analog machines for that matter.   Being able to get hands on and adjust things and see how it plays out. 

Share this post


Link to post
Share on other sites

At least you can take it apart and fiddle and not worry about the warranty. 

Has anyone out there set up to do repairs on them?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Similar Content

    • By rod-pa
      Hiyas...I recently dug a part of a pewter flatware.  I have never seen a makers mark or other identifying mark on flatware that I have dug before.  Putting it under my scope, and fooling around a lot with lighting directions, this is about the best it is going to get.  Any one have access to pewter manufacturer information?  I am stumped so far.
      The bottom is METAL, the top left looks like a B or S to me, and the right side I believe is NTA
       

    • By Dan(NM)
      Who here has dug one, if so, what mode were you in and do you remember what the VDI was? Also, does anyone have one you could do an air test in park 1.  My buddy and I are hunting an area that is old enough to possibly have one lurking about. I understand my soil, the orientation, etc will affect VDI's, I just need a baseline to start with, thanks.
    • By 31-coinshooting
      Hello everyone, this is my first post. I've been collecting coins for almost 15 years, and years ago I started rock collecting thanks to my daughter who got me interested. If you put this two ingredients together... I would like to start with metal detecting focus in current and old coins. Going to parks, lakes, old houses, beaches, rivers, you name it... but like I said before, focus mainly in current and old coins to add to my collection!!!)

      I've been doing research for which machine to get and I know for newbies like myself this can be overwhelming and tentative (NOX 600/800) because there always going to exist a better machine for a little more money than what you are planning to spend an sometimes discussions in forums can confuse you even more. I'm a very dedicated person I do not mind spend time to get to know a MD 


      Which MT would you recommend me to get to find coins anywhere (not necessarily waterproof but I will need it for shallow water)
      under 500$?

      ... I live in Maryland just as a reference.
    • By AussieDigs
      Gold Bug Pro of the PI world?
      uncomplicated, not ridiculously expensive, excellent performance!
      Which unit would it be?
    • By Steve Herschbach
      Published on May 8, 2019. Detecting veteran and reality TV star Tim Saylor tackles the question of traveling with metal detectors. How does he pack his detector, pinpointer and shovel when he flies overseas?
       
    • By AussieDigs
      I have been doing some research, whether im on the right track or not is part of the learning curve i spose!
      Are reefs/leads connected? Are they related to each other?
      I went off in another direction today. Riding the dirt bike to cover ground quickly and efficiently. No detector. Interesting to see ‘scratchings’ between reefs!
      Am i right or wrong?
       
       
       
       




×
×
  • Create New...