Compadre Schematics

[bklein]

Hi guys,
I recently bought a used Compadre. I was amazed really at its detection abilities compared to other generic detectors I have had. But it had a problem in that it beeped at the ends of abrupt sweeps. This was not due to the cable moving in the detection area. I could just lightly bump the coil with the palm of my hand and it would sound. So I sent the unit in to Tesoro. I got it back with a note saying the battery was bad and to install a new one and that they found the sensitivity was too high. ARrrgh. With a new battery it constantly beeped at the no disc. setting and was not as sensitive as original. And it still was sensitive to mild shock. I called them and was told that the coil was likely the culprit and that they had a better one they could offer. As the beeping at no disc. is not normal and was not there before I sent the unit back to them and am awaiting their call, hoping they find something this time. Any of you experience this sensitivity to mild shock? Anyone ever take the coil apart - I wonder what could be moving in there. I found that if I just slightly rotate the cable coming into the coil (black connector housing slid back) it would sound. So maybe a bad connection there. But how to fix? I'm hoping they fix it this time but if not I'd like to give it a go myself and am open to suggestions. They do actually kind of discuss this behavior in the manual. But I have never experienced this with other detectors and think it abnormally sensitive to it on this one.

[simonbaker]

Happy New Year SimonBaker . Did you look closely at that comparison Chart ?? The Tesoro Lobo Results ?? The Tesoro Lobo has amazing results on everything , NO-EXCEPTIONS , I think alot of people on this forum just do not know how "Hot" that machine is !!! Besides forum members Maxbiri and a few others , the Lobo is very over-looked . This is a new year 2009 , hopefully we will finish some un-finished projects , like the Lobo and the Relic Hawk..............Regards..........Eugene52

Lobo has alway been on my wishlist - heavy box though.

I am very curious why it performs so well and want to build it. Finishing un-finished projects definitely my goal too!

Regards,

-SB

[Eugene52]

Compadre Schematics

Happy New Year SimonBaker . Did you look closely at that comparison Chart ?? The Tesoro Lobo Results ?? The Tesoro Lobo has amazing results on everything , NO-EXCEPTIONS , I think alot of people on this forum just do not know how "Hot" that machine is !!! Besides forum members Maxbiri and a few others , the Lobo is very over-looked . This is a new year 2009 , hopefully we will finish some un-finished projects , like the Lobo and the Relic Hawk..............Regards..........Eugene52

[simonbaker]

I see good photo of Compadre PCB I must inform you of. we have what we have... only some tiny steps give us some movement forward. yep we still have not a people who can give hight definition photos but we must not cry on this!

http://www.findmall.com/read.php?22,875409,875409#msg-875409

I believe Compadre PCB will be #1 in your List

Very interesting, glad other people interested. Maybe I'll should go into tripod business, too many camera owners need one!

I have enjoyed my Compadre for many months. Soon I may have courage to cut the cable and measure the coil, then try some homemade coils. It is my only detector so I am shy to do it.

I would like to make schematic of it and compare to TGSL some time. I expect differences in discrimination circuit because Compadre has "180 deg" discrimination - no switch for all metal, just turn discrim knob to minimum.

Most dirt here is hard-packed clay very mineralized. I think I never find coin below 3 inches (7.6 cm). Very hard to dig anyway. I find objects deeper in wood chips, maybe 5 to 6 inches (12.7 to 15.3 cm). So I want more depth.

Has anyone tried this: Drill holes in box faceplate for tuning wand to adjust ground balance, sensitivity in field. Use rubber plugs for holes.

Regards,

-SB

[kt315]

I see good photo of Compadre PCB I must inform you of. we have what we have... only some tiny steps give us some movement forward. yep we still have not a people who can give hight definition photos but we must not cry on this!

http://www.findmall.com/read.php?22,875409,875409#msg-875409

I believe Compadre PCB will be #1 in your List

[simonbaker]

The 2 pots at the bottom, one is for tuning the discrimination and the other is for ground balance. I'm thinking you may could tell which of the 2 are the disc setting by seeing if the wires go to the knob control. I had a gentleman tell me that the disc pot could be altered and you would affect the high range and the low range, in fact he had altered it so that the high range would knock out the dime/ penny, that way he could cherry pick quarters. If you adjust them, make sure you mark them first and use a screwdriver recommended for adjusting pots and don't touch the components on the circuit board. I did ask him how one would adjust the GB but he didn't have the instructions to do that. Oh yeah, the Compadre has the 180 disc, not 120. If you turn the disc all the way down, it will give a strong signal on nails.
There are 2 reasons why the Compadre doesn't have outstanding depth charactorists. It doesn't employ Tesoros "Hot" technology and it's coil size but it does work very well in trashy areas, both in nails and alum. In fact nail/coin tests I have conducted with it and against other detectors I have or had as well as getting some of my detecting friends do the tests, the Compadre does better than the other detectors on the tests.
You could send your detector to Mr Bill and have him put a connector so that you could attach Umax coils to it, some have done the mod themselves.

Thanks for that extra info. From my experiments, I'm guessing the pot #2 (lower left) is Ground Balance since it had an immediate effect on chatter when the coil is near the ground. With my sensitivity (pot #1) cranked counterclockwise, I find I need to crank the Ground Balance (pot #2) almost fully clockwise. Not much headroom if more GB is needed.

Also from my experiments I did have the impression that pot #3 was affecting the discrimination ranges. That one I put back to a middle setting and I'm content with how the discrimination knob scale corresponds to some air tested targets as noted previously.

This configuration feels like it makes a deeper, more sensitive detector, but I'd need to test on some marginal ground targets to confirm that.

BTW:

- What is the proper screwdriver for trim pots? I know if you're tuning with a scope you might want plastic wands to avoid effects. Since I'm tuning "blind", I'm just using a small metal screwdriver. Trying not to touch the circuit, but in the field....

- I'd be interested in what differences people find with the larger coils, anyone do some tests?

Thanks,

-SB

[Steve in MS]

The 2 pots at the bottom, one is for tuning the discrimination and the other is for ground balance. I'm thinking you may could tell which of the 2 are the disc setting by seeing if the wires go to the knob control. I had a gentleman tell me that the disc pot could be altered and you would affect the high range and the low range, in fact he had altered it so that the high range would knock out the dime/ penny, that way he could cherry pick quarters. If you adjust them, make sure you mark them first and use a screwdriver recommended for adjusting pots and don't touch the components on the circuit board. I did ask him how one would adjust the GB but he didn't have the instructions to do that. Oh yeah, the Compadre has the 180 disc, not 120. If you turn the disc all the way down, it will give a strong signal on nails.
There are 2 reasons why the Compadre doesn't have outstanding depth charactorists. It doesn't employ Tesoros "Hot" technology and it's coil size but it does work very well in trashy areas, both in nails and alum. In fact nail/coin tests I have conducted with it and against other detectors I have or had as well as getting some of my detecting friends do the tests, the Compadre does better than the other detectors on the tests.
You could send your detector to Mr Bill and have him put a connector so that you could attach Umax coils to it, some have done the mod themselves.

[simonbaker]

Have you considered that the Compadre is perhaps just not as sensitive as some of the other Tesoro detectors?
Have a look at the attached chart:

Great chart, thanks!

Of course I'd like to milk as much as I can out of the cheap detector (isn't that what mods are all about?). But mainly I'd like to understand the pots so I'm not making it worse instead of better.

Always appreciate your excellent info.

Regards,

-SB

[Qiaozhi]

Thanks Max. It will take some time learning how these circuits work so I appreciate your patience with my beginning questions.
-----------------------

If anyone is familiar with the new Compadre, I'd like to confirm the meaning of the three trim pots on the circuit board. I have been moving them, but not really understanding what I'm doing, so it is time to better understand before I make a mess.

The attached picture shows approximately where the pots are if you hold the metal detector in front of you as if you are using it.

Steve in MS identified the top pot (#1) as the gain pot. I think it was factory preset almost full counterclockwise except for a 1/4 turn. By turning it full counterclockwise, the gain increases slightly and I increased my depth in air from about 5 inches to 6 inches and maybe more.

But when I put it on the dirt, it beeped intermittently, any movement made a beep.

I tried turning the other pots to see the effect. I found that if I turn pot #2 fully clockwise, the ground does not make a beep. I think this configuration may be a little better than the factory setting, but I didn't record the exact factory setting (stupid me). If I turn pot #2 counterclockwise more than a tiny bit, the ground starts beeping.

Pot #3 I cannot determine what the effect is. It may shift the discrimination settings on the DISC knob control on the front of the unit. But I'm not sure. I have set it sort of in the middle range where I think it was from the factory.

Using air tests and my new settings, the Compadre discriminator part is still working quite well. A setting to Iron cuts out a paperclip but allows a nickel and a 14K gold ring. Setting to Foil allows a nickel but cuts out the gold ring. Setting to nickel cuts out a nickel but allows a dime, penny etc.

Although increasing sensitivity (pot 1) does increase air depth a little, I don't know if it really increases it in the ground. I would need to test that, but it is difficult to open the machine outdoors and work the trim pots and get reliable measurements with buried targets.

As Max says, it would be nice to have these pots on the outside. Because they are tiny surface mount parts it would be tricky to do that surgery, and I would think the long leads might cause circuit problems. One could perhaps drill tiny holes in the case to access the trim pots from the outside (letting in dirt also). But trim pots probably might wear out, not designed for much turning.

So if anyone knows for sure what all these pots do and how they interact, I'd like to hear. In time I hope to trace the circuit so we can analyze it and compare it to existing circuits.

Cheers,

-SB

Have you considered that the Compadre is perhaps just not as sensitive as some of the other Tesoro detectors?
Have a look at the attached chart:

[simonbaker]

Compadre Pots

Thanks Max. It will take some time learning how these circuits work so I appreciate your patience with my beginning questions.
-----------------------

If anyone is familiar with the new Compadre, I'd like to confirm the meaning of the three trim pots on the circuit board. I have been moving them, but not really understanding what I'm doing, so it is time to better understand before I make a mess.

The attached picture shows approximately where the pots are if you hold the metal detector in front of you as if you are using it.

Steve in MS identified the top pot (#1) as the gain pot. I think it was factory preset almost full counterclockwise except for a 1/4 turn. By turning it full counterclockwise, the gain increases slightly and I increased my depth in air from about 5 inches to 6 inches and maybe more.

But when I put it on the dirt, it beeped intermittently, any movement made a beep.

I tried turning the other pots to see the effect. I found that if I turn pot #2 fully clockwise, the ground does not make a beep. I think this configuration may be a little better than the factory setting, but I didn't record the exact factory setting (stupid me). If I turn pot #2 counterclockwise more than a tiny bit, the ground starts beeping.

Pot #3 I cannot determine what the effect is. It may shift the discrimination settings on the DISC knob control on the front of the unit. But I'm not sure. I have set it sort of in the middle range where I think it was from the factory.

Using air tests and my new settings, the Compadre discriminator part is still working quite well. A setting to Iron cuts out a paperclip but allows a nickel and a 14K gold ring. Setting to Foil allows a nickel but cuts out the gold ring. Setting to nickel cuts out a nickel but allows a dime, penny etc.

Although increasing sensitivity (pot 1) does increase air depth a little, I don't know if it really increases it in the ground. I would need to test that, but it is difficult to open the machine outdoors and work the trim pots and get reliable measurements with buried targets.

As Max says, it would be nice to have these pots on the outside. Because they are tiny surface mount parts it would be tricky to do that surgery, and I would think the long leads might cause circuit problems. One could perhaps drill tiny holes in the case to access the trim pots from the outside (letting in dirt also). But trim pots probably might wear out, not designed for much turning.

So if anyone knows for sure what all these pots do and how they interact, I'd like to hear. In time I hope to trace the circuit so we can analyze it and compare it to existing circuits.

Cheers,

-SB

Hi,
good questions. At first I was a little in troubles with them but then find that a member (goodrat) posted about diagrams of bandidoII (well, actually, if I remember well goodrat owns a modified compadre that acts like a bandido)... but also other informations I get from e.g. Qiaozhi and other members.

You can find e.g. my tuning data for TGS looking at page #57 of TGS thread: I posted a lot of pictures of my readings of phase etc for plenty of test points I made on my TGS.

You can find goodrat's diagrams too and compare them: you'll notice tesoro's disc and geb setting are pretty close from one detector to another. The big change is always related to disc interval that in some MDs is larger.

Tesoro defines various disc circuits as D90, ED120, ED180 where number indicates degrees interval of disc employed: for example , if I remember well, the compadre uses ED120 so 120° of disc interval.

The tuning for geb is made in a way you sample RX signal at around zero crossing; disc instead has a starting point of sample depending of the disc circuit employed in the particular MD... then you can "slide" the sample in a way you cover a sector near the peak of RX signal. The geb/disc sampling strategy is made in a way you have always around 90° phase-out between the two... so that's why you sample one about at zero crossing and other channel at about peak of sinus.

When you build a clone of e.g. bandidoII or TGS you end-up (if do all right) with already "partially" tuned device: you have to set then e.g. geb according to soil (there's a knob for manual setting on bandidoII) manual for each soil or (like in TGS) using a preset trimpot: when you use a preset trimpot, sure you tune for a medium worse soil, but sure this way you actually cannot use MD in other very bad mineralized soil... unless you unsolder the trimpot and add a manual control on front panel, like a multiturn pot (similar to bandidoII situation).

The fact you have many trimpots say just this: you have many factory presets.... and solution for to make your MD more easy on worse soil is e.g. translating geb into manual mode using a real pot instead.

Usually the machines with many presets are for easy soil and ease of use.... like compadre is but do not give warranty on worse soil conditions like others can give (e.g. toltec or also bandidoII): original tgs is also this way about geb (tesoro made it with fixed geb preset... so an internal trimpot), but has other controls accessible to the user.

Kind regards,
Max

[Max]

Maybe too many questions, but always appreciated...

A question about Ground Balance and Disc trim pots...

What measurement would you make to confirm they were set best, or is it just a magic setting that Tesoro uses based on experience with soils, etc?

If you build your own Amigo, Bandido, etc.... how would you trim those pots without Tesoro's data?

Regards,

-SB

Hi,
good questions. At first I was a little in troubles with them but then find that a member (goodrat) posted about diagrams of bandidoII (well, actually, if I remember well goodrat owns a modified compadre that acts like a bandido)... but also other informations I get from e.g. Qiaozhi and other members.

You can find e.g. my tuning data for TGS looking at page #57 of TGS thread: I posted a lot of pictures of my readings of phase etc for plenty of test points I made on my TGS.

You can find goodrat's diagrams too and compare them: you'll notice tesoro's disc and geb setting are pretty close from one detector to another. The big change is always related to disc interval that in some MDs is larger.

Tesoro defines various disc circuits as D90, ED120, ED180 where number indicates degrees interval of disc employed: for example , if I remember well, the compadre uses ED120 so 120° of disc interval.

The tuning for geb is made in a way you sample RX signal at around zero crossing; disc instead has a starting point of sample depending of the disc circuit employed in the particular MD... then you can "slide" the sample in a way you cover a sector near the peak of RX signal. The geb/disc sampling strategy is made in a way you have always around 90° phase-out between the two... so that's why you sample one about at zero crossing and other channel at about peak of sinus.

When you build a clone of e.g. bandidoII or TGS you end-up (if do all right) with already "partially" tuned device: you have to set then e.g. geb according to soil (there's a knob for manual setting on bandidoII) manual for each soil or (like in TGS) using a preset trimpot: when you use a preset trimpot, sure you tune for a medium worse soil, but sure this way you actually cannot use MD in other very bad mineralized soil... unless you unsolder the trimpot and add a manual control on front panel, like a multiturn pot (similar to bandidoII situation).

The fact you have many trimpots say just this: you have many factory presets.... and solution for to make your MD more easy on worse soil is e.g. translating geb into manual mode using a real pot instead.

Usually the machines with many presets are for easy soil and ease of use.... like compadre is but do not give warranty on worse soil conditions like others can give (e.g. toltec or also bandidoII): original tgs is also this way about geb (tesoro made it with fixed geb preset... so an internal trimpot), but has other controls accessible to the user.

Kind regards,
Max

[Max]

Thanks Max once again, these are great ideas...

I hopefully restored the pot settings then turned just the one that Steve confirmed for me (at top of PCB as you hold the detector) counterclockwise, and I did get some significant benefit, so very grateful for that to begin with, I was a little sour not getting the "Max" () out of my detector...

I'm very interested in a larger coil and what kind of connector you would wire into the cable that would make clean connections, since I'd have to cut the cable on the Compadre and install a connector. If a large coil would help me go deeper at the beach, that would be exciting, although I have to think twice about losing that Tesoro warranty ...

I do have an oscilloscope and some circuit background (although I haven't etched CBs so far) so I'm interested in the procedures involved with making the coil.

So... thanks again for the ideas and references.

By the way, do any of the circuits, such as the Bandido II or Golden Sabre work on solderless breadboards, or do you need to etch a PCB for them to work at all?

Thanks,

-SB

Hi,
I never tryed mounting whole schematic on breadboard... too complex and lot of wires required. I think that circuits like bandidoII and similar will work too but with lot of troubles related to e.g. self oscillations and cross-talks due to cross of wires.

Sure you can make one of them breadboarding stuff... but results will be not like when using a real PCB. Think e.g. at comparators you can get them work easy on breadboards... but then the noise there will make them saturate very easy , in a large amplification chain.

Some parts are less critical e.g. oscillator , frequency divider and sampling gates and also audio stage... but the real problems will start at preamp and next amplifiers till comparators where problems you'll see as very fast self-oscillations and much of instability.

Kind regards,
Max

[simonbaker]

Maybe too many questions, but always appreciated...

A question about Ground Balance and Disc trim pots...

What measurement would you make to confirm they were set best, or is it just a magic setting that Tesoro uses based on experience with soils, etc?

If you build your own Amigo, Bandido, etc.... how would you trim those pots without Tesoro's data?

Regards,

-SB

Hi,
you made it the wrong way I think... but now that the MD is already untuned (you probably changed the geb and disc presets used in factory tuning) you can also experiment more with it...

Sure you cannot get more depth by just changing that trimpots positions... pretty easy and already explained: you have just 10Vpp amplitude at TX coil... and coil is also small so depth will be always as before this way.

It's like when you try to mod your motorcycle... and start replacing the carburetor filter... to get what ??? 0.01 HP more ? Maybe 0.01mph more ???

No, no man... you need more and more HPs to go deeper into soil...

A good try would be modding the osc supply , raising to (at least) +8V... but , as always, do at your own risk (like the pot changes of above).

You could also avoid messing the circuit and just make e.g. a larger coil for it... but you'd better have a scope handy to make one good way... cause few people really tune coils right way using just multimeters.

The Compadre could take advantage of existing recipes (look e.g. at TGS thread) and homemade coils designs... you could probably use Ivconic's recipe without mods on Compadre : it's a large (27cm diameter) DD type coil for uMax series... I've made many and works cool on both TGS and bandidoII... recipe it's also easy

100turns for TX , 105 for RX, wire is 30AWG

Call this : soft tuning!

Best regards,
Max

[simonbaker]

Thanks Max once again, these are great ideas...

I hopefully restored the pot settings then turned just the one that Steve confirmed for me (at top of PCB as you hold the detector) counterclockwise, and I did get some significant benefit, so very grateful for that to begin with, I was a little sour not getting the "Max" () out of my detector...

I'm very interested in a larger coil and what kind of connector you would wire into the cable that would make clean connections, since I'd have to cut the cable on the Compadre and install a connector. If a large coil would help me go deeper at the beach, that would be exciting, although I have to think twice about losing that Tesoro warranty ...

I do have an oscilloscope and some circuit background (although I haven't etched CBs so far) so I'm interested in the procedures involved with making the coil.

So... thanks again for the ideas and references.

By the way, do any of the circuits, such as the Bandido II or Golden Sabre work on solderless breadboards, or do you need to etch a PCB for them to work at all?

Thanks,

-SB

Hi,
you made it the wrong way I think... but now that the MD is already untuned (you probably changed the geb and disc presets used in factory tuning) you can also experiment more with it...

Sure you cannot get more depth by just changing that trimpots positions... pretty easy and already explained: you have just 10Vpp amplitude at TX coil... and coil is also small so depth will be always as before this way.

It's like when you try to mod your motorcycle... and start replacing the carburetor filter... to get what ??? 0.01 HP more ? Maybe 0.01mph more ???

No, no man... you need more and more HPs to go deeper into soil...

A good try would be modding the osc supply , raising to (at least) +8V... but , as always, do at your own risk (like the pot changes of above).

You could also avoid messing the circuit and just make e.g. a larger coil for it... but you'd better have a scope handy to make one good way... cause few people really tune coils right way using just multimeters.

The Compadre could take advantage of existing recipes (look e.g. at TGS thread) and homemade coils designs... you could probably use Ivconic's recipe without mods on Compadre : it's a large (27cm diameter) DD type coil for uMax series... I've made many and works cool on both TGS and bandidoII... recipe it's also easy

100turns for TX , 105 for RX, wire is 30AWG

Call this : soft tuning!

Best regards,
Max

[Max]

I opened up my new Compadre (with 5.75" coil) control box to see if I could tune it "hotter", that is, more depth at the risk of more noise.

I only saw three small trim pots. They only turned one or two turns at the most. They were each set somewhere in the middle of their range. I turned each one max clockwise and then max counterclockwise.

I did not see any real difference in depth with my indoors air tests. I detect american coins at about 5 inches (12.7 cm) max; pennies, dimes, and quarters (clad) all register about the same depth, the dime a little less.

When I turned each pot to its max and min value, never did the detector go unstable or chirp or anything -- it just remained silent.

I'm pretty disappointed in the depth. I don't expect fancy features for such a low cost detector, but I was still hoping it could get a little more depth in all metal mode; I was really hoping there would be a pot that could make it more sensitive, but the trimmers don't seem to change much.

Has anyone (Steve in MS?) done any tests on the latest Compadre and found a way to tune it more sensitive (without modifications)? If so, what did you find?

BTW: at least the descriminator does work pretty well anyway in air.

Hi,
you made it the wrong way I think... but now that the MD is already untuned (you probably changed the geb and disc presets used in factory tuning) you can also experiment more with it...

Sure you cannot get more depth by just changing that trimpots positions... pretty easy and already explained: you have just 10Vpp amplitude at TX coil... and coil is also small so depth will be always as before this way.

It's like when you try to mod your motorcycle... and start replacing the carburetor filter... to get what ??? 0.01 HP more ? Maybe 0.01mph more ???

No, no man... you need more and more HPs to go deeper into soil...

A good try would be modding the osc supply , raising to (at least) +8V... but , as always, do at your own risk (like the pot changes of above).

You could also avoid messing the circuit and just make e.g. a larger coil for it... but you'd better have a scope handy to make one good way... cause few people really tune coils right way using just multimeters.

The Compadre could take advantage of existing recipes (look e.g. at TGS thread) and homemade coils designs... you could probably use Ivconic's recipe without mods on Compadre : it's a large (27cm diameter) DD type coil for uMax series... I've made many and works cool on both TGS and bandidoII... recipe it's also easy

100turns for TX , 105 for RX, wire is 30AWG

Call this : soft tuning!

Best regards,
Max