2nd discrimination Pot on Tracker 4 and Resistor on meter?

KandK_Dad

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has anyone added a second pot inline to the discrimination on the tracker 4 for better 'fine tuning'? I was thinking about this last week. I haven't measured what the current one is but it wouldn't be hard to add a second or third for some super find tuning in disc mode. I know it's a warranty void kinda operation but TBH the thing is cheap enough anyways that it's perfect for tinkering with. Another thing I was thinking about is, Has anyone added any resistance inline with the analog meter as to try to get something more usable out of it. I don't look at it and just listen to tones but it would be interesting to know if it could be made truly workable.

MTA: Well squash getting the meter to read. I tried reading junk, silver, ect at different 'depths' and it kept reading the exact same. Hooked up to the voltmeter I just kept getting the same thing over and over again. So I promptly disconnected it. It doesn't tell me anything other than which way is right when I find something.
 
Not sure how sensitive you want the disc. but you could change out the singal tune linear potentiometer with a multi turn potentiometer of the same OHM's. The values would be the same on top end and bottom end but it would take more turns to get there hense more "sensitive".
 
Not sure where these are located, but I remember ground balancing my tracker turning a pot with a screwdriver, I had better results after
 
Not sure where these are located, but I remember ground balancing my tracker turning a pot with a screwdriver, I had better results after

There is a screw driver adjustment on the circuit board itself. Blue box, center, labeled VR1. I have mine apart for a mod and was wondering about it.

KA5q7dLl.jpg


Edit:

I did a little research. Here's a pretty helpful link covering the basic technology of a metal detector. VR1 is most likely what you're referring to Dorado.

http://www.talkingelectronics.com/projects/200TrCcts/MetalDetectors/MetalDetectors-1.html
 
There is a screw driver adjustment on the circuit board itself. Blue box, center, labeled VR1. I have mine apart for a mod and was wondering about it.

KA5q7dLl.jpg

it also seems to be the only one.

what I did at that time was:

- with a fine maker, mark the default adjustment of the pot in case you need to go back to the original configuration

- search a clean spot (no other metal objects) like the kind of ground you normally hunt

- bury a quarter at the point of getting an iffy signal

- then carefully adjust the pot with a precision screwdriver, passing the coil above the buried quarter in order to find the better response. It worked for me about 3 years ago


Edit: cool link, I'll bookmark it!


Great info, it talks about the adjustments :yes:
 
Ok here goes nothing! I'm not sure how to word or explain this so I hope this makes sense... The blue pot you guys are refering to is a multi turn mini potentiometer. The normal disc. and sensitivity knobs you use are singal turn potentiometers. They are both adjustable resistors the only difference is the single turn only takes one turn to go from minimum to maximum and the multi turn takes multiple turns to get from minimum to maximum. The multi-turn is used for things you want real fine tuning of. You guys could remove the blue pot off the board and wire in a full size multi-turn potentiometer and mount it on your md box with a knob so you have control of it while you are out in the field hunting. There should be numbers on the blue pot and if you google what you see on the pot with the word "pot" behind it you should be able to find what ohm's it is. To find out how many turns it is: mark its position turn it counter clock wise counting the full turns untill it stops (be sure to write down how many turns for later). Now turn it clock wise till it stops counting the turns and this is how many turn potentiometer it is. Now turn it back counter clock wise till it stops then turn it back clock wise the first number of turns you wrote down and it will be back at factory setting. Here is a 10-turn, 100ohm potentiometer for an example of what you need, but you need to find your ohm's and turns. Be sure to get a "linear" potentiometer. Hope I didn't loose anyone but this would make it so you could "hot" tune your md on the fly. GL hope this helps!

http://www.digikey.com/product-detail/en/3590S-2-101L/3590S-2-101L-ND/2534352
 
Last edited:
Ok here goes nothing! I'm not sure how to word or explain this so I hope this makes sense... The blue pot you guys are refering to is a multi turn mini potentiometer. The normal disc. and sensitivity knobs you use are singal turn potentiometers. They are both adjustable resistors the only difference is the single turn only takes one turn to go from minimum to maximum and the multi turn takes multiple turns to get from minimum to maximum. The multi-turn is used for things you want real fine tuning of. You guys could remove the blue pot off the board and wire in a full size multi-turn potentiometer and mount it on your md box with a knob so you have control of it while you are out in the field hunting. There should be numbers on the blue pot and if you google what you see on the pot with the word "pot" behind it you should be able to find what ohm's it is. To find out how many turns it is: mark its position turn it counter clock wise counting the full turns untill it stops (be sure to write down how many turns for later). Now turn it clock wise till it stops counting the turns and this is how many turn potentiometer it is. Now turn it back counter clock wise till it stops then turn it back clock wise the first number of turns you wrote down and it will be back at factory setting. Here is a 10-turn, 100ohm potentiometer for an example of what you need, but you need to find your ohm's and turns. Be sure to get a "linear" potentiometer. Hope I didn't loose anyone but this would make it so you could "hot" tune your md on the fly. GL hope this helps!

http://www.digikey.com/product-detail/en/3590S-2-101L/3590S-2-101L-ND/2534352

that makes sense Coin chaser and the knob addition sounds a good idea, I don't know if it would work or will be simple to adjust with the tracker on the fly, maybe on a threshold machine could be easier to do
 
Not sure how sensitive you want the disc. but you could change out the singal tune linear potentiometer with a multi turn potentiometer of the same OHM's. The values would be the same on top end and bottom end but it would take more turns to get there hense more "sensitive".
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I keep thinking about this.

So I replace the blue VR1 single-turn pot with a physically robust multi-turn linear pot of the correct ohmic value. I'm capable of that.

Now please finish my thinking for me........ What will that mod do for me and my BH Tracker? I think it will enable me to "very fine tune" the level of discrimination via a knob, while in the field. Izzat correct?

Or will I be achieving the ability to "very fine tune" the level of sensitivity?

Thanks, folks......good thread!!

FjLee
 
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

I keep thinking about this.

So I replace the blue VR1 single-turn pot with a physically robust multi-turn linear pot of the correct ohmic value. I'm capable of that.

Now please finish my thinking for me........ What will that mod do for me and my BH Tracker? I think it will enable me to "very fine tune" the level of discrimination via a knob, while in the field. Izzat correct?

Or will I be achieving the ability to "very fine tune" the level of sensitivity?

Thanks, folks......good thread!!

FjLee

Maybe both?

The thread started talking about fine tuning the Disc. and I suggested replacing the singal turn pot with a multi-turn pot. The multi turn pot would do the same thing as the single turn pot but take more of a turn to get the same results. For example if you were trying to disc. out old pull tabs but not new pull tabs it would only take a tiny tweek which is hard to be accurate with. If you had a multi-turn pot for disc. you would have a quarter turn from old pull tabs to the new pull tabs so you could get it right where you want it with more room for error.

Now this thread has switched to the VR1 pot on the board. I don't own a BH and I haven't messed with the pot but from some of the guys on here it seams that it might be a internal ground balance pot. That pot can be turned from a mini to a normal size with a knob and mounted in the box just like the existing knobs. I have been trying to find a board schematic to try and see for sure what the VR1 pot does but I haven't one yet.
 
interesting link from another site

VR1 Pot/1K

Plus I checked the ohms on the current discrimination pot and it comes in at 8.02Kohm.
 
interesting link from another site

VR1 Pot/1K

Plus I checked the ohms on the current discrimination pot and it comes in at 8.02Kohm.

Thats the ohms you are getting with were its set and with it being attached to the board. 1k ohm is 1000 ohm's, the pot is a 1000 ohm pot. None the less it seams the only thing you can do to adjust it is the ferrite trick and thats it. No point in changing it to a full size pot with a knob then.:( Iwas hopping to find more info of mods for this MD.
 
I had it set at disc off, and I'm still thinking the 2nd pot would do the trick for supertuning

just gotta find one and figure out how to solder it all up nicely.
 
If your hunting in all metal with disc. off where are you talking about adding a second pot?

mis-print. I was measuring the ohms while the switch was in all metal, not that it matters.

It would be kinda stupid to worry about disc when in all metal mode.

I also have a 1K ohm pot. on order so hopefully I'll be able to test it out mid next week.
 
mis-print. I was measuring the ohms while the switch was in all metal, not that it matters.

It would be kinda stupid to worry about disc when in all metal mode.

I also have a 1K ohm pot. on order so hopefully I'll be able to test it out mid next week.

Be sure to update us when you try out your mod I'm curious how it will work out! GL with the mod.
 
VR1 settings ?.

Dear Dorado ,

When you did the settings test of the VR1 potmeter , in what position was the discrimination pot set.
Was it on half way or was it off ??.
I refer to your post on 02-05-13.
Need some help if it,s possible.

Many thanks , Walther from Holland.
 
hmm never too late to ask..wondering how that pot meter mod went..it's the only mod i havn't done to my BH tracker 4 yet. i'm going ahead with a new pot, ordered one to relocate on my redesigned face plate. i'll re-post on this thread once successful. (this is my first post ever btw)
 
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