TESORO GOLDEN SABRE

[kuraja]

Why does disc/all metal affect your nulling? What are you looking at?

If nulling by testing depth with coin, then yes, it matters.

Regards,

-SB

I am nulling with Al coin in All metal mode. Somehow, when you switch it in Disc, the iron is not rejected if the nulling is wrong. That is what i found out. Nulling can be done this way, strange?!

[simonbaker]

I am nulling with Al coin in All metal mode. Somehow, when you switch it in Disc, the iron is not rejected if the nulling is wrong. That is what i found out. Nulling can be done this way, strange?!

In other words, you null by finding max depth with coin? Is that right?

I am interested to know the voltages on caps C12 and C15 when iron is not rejected due to wrong nulling. If you can perform that test, please post voltages. Also, what are voltages with correct nulling?

Regards,

-SB

[ivconic]

Ok! Now here is my strange looking coil.


As you can see, the smaller diameter will offer more pinpointing feature in high trash areas where depth isn't an issue. Although, the depth of this 20 cm coil is in air about 25cm for a 1.5 cm coin.
I do advise to null at ALL METAL! Later switch to disc and see if the iron is rejected. If not, you nulled wrong! Try again, in all metal mode. If you here double beep after one swing of a coin, then something is wrong at the coil connection (my guess is Tx). Reverse the connection and try again, until you get single beep at any hight by swinging the coin. I do prefere nulling by using a BOTTLE CAP, yes! A bottle cap. It is Al metal, very good to see if your coil is getting enough depth and the detector will be sensitive to gold. Switch then to disc, and remember, when nulling, always leave disc pot at 1/2 of the range, and move slightly to 65%. You will then be able to dicriminate between iron, steel and rest of the metal easily.
Hope this helps, and remember, no Discrimination, no real TGSL.

Wrong!
During process of nulling you not suppose to take iron as reference at all.
Yes it is nulled in All Metal mode. But you have to take ferrite rod as reference. GEB trimmer on 1/2. Null to position where ferrite rod is almost fully rejected - just to produce occasional "cracks". Ferrite rod is 5cm long and wide and slow swings are performed about 5-10cm over coil surface during nulling. When this achieved, later fine correction is done by slice readjustment of GEB trimmer...

Speaking of coil dimensions you are presenting here...i can suggest more turns; ~150 for RX and ~140 for TX.

Cheers!

[metaldetector107]

why so quiet????

Hi all

i think it is not fair to leave Tesoro thread so quiet, why dont you try to invent some new idea to make TGSL most powerfull detector in the world at least you can help many many needy and poor experience people's like me. please Ivconic Max Qiaozhe Esteban Simon and all try using LM324 instead lm358 try to omit 100p capacitors it is so hard to find best quality
please please more ideas.

best regards

[simonbaker]

Hi all

i think it is not fair to leave Tesoro thread so quiet, why dont you try to invent some new idea to make TGSL most powerfull detector in the world at least you can help many many needy and poor experience people's like me. please Ivconic Max Qiaozhe Esteban Simon and all try using LM324 instead lm358 try to omit 100p capacitors it is so hard to find best quality
please please more ideas.

best regards

Once I feel I have a good performing MD, I intend to try some other chips to see what the affect is. Could be a while...

Regards,

-SB

[ivconic]

Older Tesoro models like TGS,Silver,Bandido etc..etc.. do have pretty limited area of detection. If you manage to make good 27cm DD coil to reach 1e coin up to 34cm in air than that is it. Only much larger item it will detect a bit better. So it will stay limited to those 34cm and less (soil conditions). Same thing with smaller diameter coils. Recently i made 21cm DD coil and it is performing pretty good - 1e coin at 27cm in air. No false signals, very stable, excellent disc. Excellent performing on soil. And very loud and sharp audio!
But... larger items it is also detecting up to that limit...maybe 3-4cm more. No matter how large is the item - similar "depths" in air.
So...it is limited. It is not about TX power here. TX power at TGS/TGSL is quite enough. It is much more about RX stage and coil.
I had some doubts about that, but than i got original Bandido II and i noticed same occurrence and behavior. So...it is not about my (our) handmade - it is general.
Once i realized that i just took it as reality. TGS/TGSL is good as it is. Best you can do is to put more effort to make and balance better coil. With my previously balanced coils (in the past) i achieved some 36 to 45cm in air for 1e coin, but than i realized - no benefit from those on real soil, depths in soil were same as with latest coils (1e at 30cm). Only differences between those coils (in the past and recent) were in residual voltage and audio strength. In the past i kept residual voltages under 1mV and got more inches in air and...very weak and mum audio. Nowdays i keep residual voltages around 4mV and benefit is loud and sharp audio. On soil those coils performs, as i said, pretty same.
So it is all for-each-other very dependable! Very important to know this!
"Chain reaction". Coil dictates all the rest in detector.

Conclusion;
not much sense in modding the rest of schematic if coil is not done well.
So i suggest to you to also take 4mV residual voltage at RX as MUST default. I made over 35 coils so far and that's how established this - pure rough experience, statistic and practice.
That was also the main reason why i insisted to get any similar original Tesoro - to see what is situation at those, originals.

I think those at Tesoro also realized this long time ago. Newer series (Tejon,Vaquero,Cibola etc..etc..) acts much different than older series.
I had chance only to check Tejon and Vaquero on soil. I hadn't chance to open one of those and trace out some stages. Pity. But also i measured coils which came with those. Much different coils than those we make here!
Inductance at newer coils are much different - looks more like Minelab coils for Musketeer and RH....some ~1mH for TX and ~14-16mH for RX!
Newer Tesoros now are not looking "limited". Meaning large items those detecting at much more distances!
I am looking forward to see some traced out schematic from newer Tesoro. Mostly am interested to see TX stage and RX front end.
Regards!

[Qiaozhi]

In the past i kept residual voltages under 1mV and got more inches in air and...very weak and mum audio. Nowdays i keep residual voltages around 4mV and benefit is loud and sharp audio. On soil those coils performs, as i said, pretty same.
So it is all for-each-other very dependable! Very important to know this!
"Chain reaction". Coil dictates all the rest in detector.

This confirms my previous statements concerning coil nulling. i.e. it is not a good idea to try and achieve 0V residual at the RX coil. Tesoro coils typically are nulled to around 12mV.

[ivconic]

Seems so. I had to make dozen a bit different coils to learn that. Only problem now is how to establish right values (mV) because multimeters we are using are different and with small jitters. At me it is 4mV, at somebody else it can be 10mV...or more...or less. I guess you are using value measured with some nice scope (most accurate). Pity i don't have such scope. My scope is old and not in so good shape, so i am mostly relying on results measured with one pretty descent multimeter. Yet...i have 3-4 various and all are reading a bit different values. I took this, last one, as most accurate. Recently bough it and am only using it for measurements on coils. So 4mV is value measured with it. I am aware it is not real voltage, but had to adopt it as sort of reference for further works. So...with that same multimeter i am reading 3.4mV (or it was 4.3mV ...!?!? Forgot it!) residual voltage at original 8" Brown coil with Bandido II. And also at same time exactly 4mV at my latest 21cm coil for TGSL (connected on it).
Would be good if you can find some Brown coil and measure with your equipment, so we than will know differences. But than again....nobody can guarantee that all original coils were exactly same balanced...
That's why is good everybody of use here to find out and adopt own references for further works.
Regards!

[geminis74]

sorry if my questions are repeated, but do not understand English and I'm a little confused:
1 - the TGSL without connecting the coil makes a sound?
2 - at the track where I should be-5V go ten 0.74V someone knows what is that?
3 - when I connect my coil the TGSL not stopped ringing since?
thanks in advance to all.

[geminis74]

http://www.subirimagenes.com/otros-u...d-3445833.html

blue is the track where I have 0.74V?, anyone has any idea why please

[geminis74]

http://s4.subirimagenes.com/otros/pr...33untitled.jpg

[ivconic]

sorry if my questions are repeated, but do not understand English and I'm a little confused:
1 - the TGSL without connecting the coil makes a sound?
2 - at the track where I should be-5V go ten 0.74V someone knows what is that?
3 - when I connect my coil the TGSL not stopped ringing since?
thanks in advance to all.

1) No. It should not make a sound.
2) Since it is sort of chain relation from TX oscillator to negative voltage generation, you must trace signal from TX 2N2907 collector to chopper stage.
Oscillator works? Yes? No? If yes than next to check is 2N2222 (buffer to 4024).There is frequency on 2N2222 collector? Yes? No? Next...You must have main frequency reading on 4024 pin 1. Than also you must have frequency/2 reading on 4024 pin 12. If yes than everything is OK, except those two transistors in chopper stage (2N3906 and 2N3904). Those can be good and yet not working there, most probably due weak signal on their bases (not enough to excite those transistors). Replace those with different kind; BC107&BC177, BC547&BC557 etc..etc...

3) This is related to already explained problem you have there. Once you get proper negative voltage (-6.xx volts) everything will come on it's place.

Regards!

[geminis74]

ivconic thank you very much, it finds.

[geminis74]

Hello, icvonic.
my coil is not well (14.7 Ohms TX, RX 16.3 Ohms) hare a new one with more turns of wire.
in TR1 collector is 16.8 khz
at CD4024 pin1 is 16.8 khz, 8.4 khz pin12.
is that the problem of not get-6v and not stop ringing?
C4 pin+ reaches -5.99V

[ivconic]

Hello, icvonic.
my coil is not well (14.7 Ohms TX, RX 16.3 Ohms) hare a new one with more turns of wire.
in TR1 collector is 16.8 khz
at CD4024 pin1 is 16.8 khz, 8.4 khz pin12.
is that the problem of not get-6v and not stop ringing?
C4 pin+ reaches -5.99V

-5.99 is almost right. What is situation now with audio?
Any changes?