Ground balance modded my Silver U-max-some details for the very brave

[Darkflight]

I have very little electronic experience. But I have tinkered for years & have a decent multi meter & soldering tools.

I have a Silver that works well for me-very light & I have a good coil selection started. Problem is here in Oregon we have a ton of hot rocks & I have to watch pushing the internal GB adjustment too far or I will start falsing when I hit a patch of rocks. There is only 1 pot inside the Silver & it is a tiny thing. Very sensitive to adjustments. Mark it with a fine marker before you change the factory setting so you can go back is my advice if you want to make an internal adjustment.
The Pot from the factory-it ranges 0 to 190k+ ohms. When I tested my factory setting it was approx 38K ohms.So you can see how it is easy to make too large an adjustment.

After reading about the Tesoro Cibola GB mod in this PDF I thought I'd see if it could be done on a Silver.
Here's the very well done PDF
http://home.earthlink.net/~puddlepirate/data/CIBOLA%20Ground%20Balance%20Mod.pdf

Thanks for that helpful how to!

OK-where to get the needed 50k pot as suggested?...I'm on a partial disability & money is tight. But I did have a useless "Famous Trails' detector I had bought at Big 5. It was truly useless under any conditions & I would have felt bad selling it off.So I tore it apart. Lotsa knobs & waddya know-2 of the 50K pots I needed.Joy!.

So I de-soldered the donor & tested which terminals & set it at 38K like the old one. I soldered in the wires as best I can. I'm kinda shaky on the small stuff nowadays. But I got it done reasonably well. Then I carefully de-soldered the internal factory pot. I determined the 2 connections on the bottom of the old pot were where the connection needed to go. Its just 2 wires. But in this case the old pot terminals had to be used. in the PDF file he uses some spare lugs on the circuit board. I did not see any spares here so off the old one went & the new wires-connected to the new 50K pot were soldered on.

I chose the lower right hole to mount it. I frankly wish I had chosen an upper hole as it is easy to bump now. But it is easy to re-adjust so no bigee.I also used some painters tape to keep the wires from touching as it was close.

As you can see I've marked my faceplate for various disc "out" settings. This helps me to do some ID as I go along & of course for trashy areas.

Hope Y'all understand my warranty is long voided now. And I frankly was taking a chance with a used POT from a POS detector-but in this case it worked GREAT!.

I set it to all metal & bob the coil up & down. I then adjust till I get noise & then back off a hair.

 

[Sven]

Nice job!
Makes the Silver a better hunter.
I haven't opened up a Silver, some one else will know, there maybe another pot inside to adjust threshold.
If so this will give you somewhat more adjustment if you add another external pot somewhere.
Since you went so far....if things don't feel right, you can drill some extra holes on the faceplate as the hole positions are already
templated out and switch your pots around some. Add a pinpoint switch where your toggle is now or add it under the grip like on the mod'd Cibola.

That's one nice thing with Tesoro's they are mod friendly, just a bit cramped on the inside.
When I mod'd my Silver Sabre Umax I switched out all the pots with smaller Alpha 12mm pots, they fit much better and you could also splurge on better quality
pots, not that you need to.
Alpha 12mm Potentiometers

The only thing I found when using the 1 turn pot, ground balancing was not as pleasant as I would have liked, still a bit toughy. So
I went with the 10 turn Bourns pot like I used in the Cibola, a little tight but fit, as long as it went in the lower left hand corner of the faceplate.
Ground balancing was extremely precise.

Most of the 10 turn pots do not have end points, they keep on turning. They just get a bit stiffer to turning when you reach the end.
I found some really nice 10 turn pots that do have end point stops, they are made by Helipot (Same size as the Bourns) you have to hunt the
web for the correct value. I got mine off ebay for $4.50 each.

Have fun with your Silver.

 

[slingshot]

I was less adventurous-I just set the one already in there-real touchy. Neato.

 

[tvr]

That's a very useful recycling effort ... old parts in a new and improved application! Well done!!
tvr

 

[LittleJohn]

I want to try this mod on my silver. I had a guy offer to do it for me, but the total cost when it was all said and done was $90 and it just isnt worth that to me......BUT....10-15 dollars in parts and some cutting and soldering ....I can do that!

 

[amcjavelin]

n/t

 

[amcjavelin]

that is cool for sure wish i had the handy work for that stuff!

 

[LittleJohn]

What was your depth increase with this modification in the areas that you hunt?

 

[Darkflight]

I just got finished using both back-to-back...The Troy X2 used to be the clear winner in depth. Now its a toss. With my 10x12 coil the Silver air tested a quarter on near full disc @ 10". However in the real world the Troy 9" coil is so close & much lighter.

So I keep the 9" stocker on the X2 & the 5.7 Coencentric on the silver. The little coil air tests almost 7" using the same quarter/technique. In the real world of a soccer field today I was wandering around with the small coil(I had just done a tot lot & was too lazy to switch) . I got a very faint/repeatable signal in all metal & then checked it as a coin on disc. It was so faint I would have sworn it was gonna be deep. It was just a corroded copper penny @ 3" or maybe a little more. But sometimes you get one at 3" that screams. Frankly I don't get a lot of deep targets as our fields are mostly modern fill.

But the big diff is I can tailor the GB to wich ever field I'm on. If I hit a gravel bed I can back off.

The coils all have a different setting & the largest coil I have (10X12) has to have the lowest setting. And the smallest coil can be cranked way up. I guess that makes sense once you think about it.

FYI my 10X12 will likely end up on the for sale board. It's a bit nose heavy for me & in the areas I hunt the Troy does fine. LMK if anyone wants it for $65.00 shipped lower 48.

 

[Jay Evans]

I have an older Silver Sabre that had the pinpoint button and Threshold knob, that was modified by Joe Bren ( Maker of the Killer B's). He did an awesome job on this little Silver Sabre & when times have gotten tough, it's always been one I've never let go. It's an awesome little detector!