TESORO GOLDEN SABRE

[erolunall]

Hello all and İvconic

I prepared a good Pcb and I found all parts for tesero golden sabre.
But I could not find BF245B transistor.Are there any equvalent for BF245B
for replacement?İvconic Thank you for Your sharings.

I will ask you if a problem during work over project.
Best Wishes
Erol Ünal

[Max]

Hi,
thanks guys for useful informations you provided. I was becoming crazy trying to find why I had so big signals with big iron pieces.

Best regards,
Max

[Darko]

Yes Max, I agree with you. Very same behavior with G.Sabre....
Comparing with Classic 3....much better, neat design this Tesoro, but lacks few things...Almost every model of Tesoro has some drawback.....But looking overall very interesting,nice machines!
I was thinking to combine from few of them and project kind of hybrid without drawbacks you mentioned....
Looking at Eldorado.....well, very simillar to G.Sabre.....
But Silver Sabre is most interesting to me, a slice better audio, but i've change it with 4N35 and 555 anyway....
Notch is very good option, but i can live without it, due less consumption and
smaller pcb.....
So i am planing to take chance with Silver Sabre.....
Only thing interesting me is; is posted schematic accurate? Anybody know?

About G.Sabre; it is enough good to keep it. I intend to take it on the real field again these days, i made anothe DD coil. Now it is working very,very good...
I do advice anybody interested to build it.It is worth of doing...!

Darko, varnish layers can go from 0.01 to 0.05mm....so far as i seen...
So if you want 0.3mm less mistake would be if you take 0.33mm as Max told you!
Also you may relly on resistance when finich coil....to compare with original..
Regards!

Thank You Ivconic.

[ivconic]

Iron


If you think on very big iron items...than dont worry! It is quite normal to make some sound on it even in full disc. mode....Dont worry. Same with few Minelabs i owned so far, same with Garrett, Fisher,White's.....
I checked this behaviour on scope with G.Sabre;

I can see huge rise of amplitude after first ampification at RX...but there is no tone or in some cases "cracked" tone which is very significant so on real field i can be absolute sure that it is iron mass.....
Very interesting is observing ferrite detection on scope;
no sound at all but huge...and i mean huge rise of amplitude!?

I finally gained what i wanted with this last coil of mine; DD coil, 21cm diamm.
0.25mm wire, TX 141 wind. and RX 150 wind.....
Main geag is when nulling coil strictly to use ferrite rod and adjust balance just slice to "crack" on rod, but only when it is so close to coil to touch it...
Than you can see that there is no sound when ferrite rod is in the middle of coil (center) but on edges it still produce "cracks" in audio....
That is well balanced coil. I tested it yesterday on very "sharp" fieald with high level of mineralisation and it showed excellent performances!
No false signals at all. Discrimination -perfect! Depth also excellent!
Found one small roman coin deeper than 15cm.....(bronze)....
But i also noticed very poor sensitivity on small and middle iron items???
Only very large iron items are detected well. Heh!? I think we cant have all!?

I dont like Bandido....sorry.... I do like G. Sabre very much cose i am coinshooter mostly...it showed as excelllent on coins so far...


Try to observe Bandido behaviour on scope while detecting various items.....
You'll see interesting things...


Few days ago i heard "bijou" that G.Sabre, such as other Tesoro's are not working well with DD coils....!? Ha,ha,ha,ha,ha,ha!!!!
Not true!

Best regards!

[Qiaozhi]

Hi ivconic,
nice to ear that your new DD coil works ok ! I'm really stupified of mine cause I get really deeper targets I've buried some time ago to test other machines, pulse induction type.
But yes there are lacks...audio...and then also this strange sensitivity to big iron objects that is not good.
The silver sabre is the best seller of old tesoro's designs and that will be a reason for that...I think it has the best audio of uMax ones.
The eldorado is claimed to be the best in hi-mineralized soil and good for coinshoting. I've found many post in other forums that talk about LOBO too very well for finding coins and relics with good disc but haven't the schematic...and never used it so I can't say nothing sure about.
Quiaozhi told me that with bandido one get signals with big iron masses due to the fact that there is much perturbation on field lines...and that's is true I think but a problem must be there cause also is distorted much lines there is always the phase info to get a useful disc out of iron...
What to say...seems that small asymm in disc stage could cause big iron to be detected easy by bandido II and other models e.g. golden sabre think are the same cause share with it some of these circuit parts.
I'll investigate how to solve (if possible) this behaviour but seems a big task
not so easy.
At first I thinked that coil must be involved but then noticed that concentric and DD give same behaviour with big iron...then realized that no big differences due to coils, just abrupt sound with DD when iron present due to different field lines distribution in the space.

Best regards,
Max

No IB detector is capable of 100% discrimination, and large ferrous targets are always a problem. The phase-shifting of the receive signal is a complex combination resulting from conductivity, permeability and transmit frequency. Unfortunately it's a fact of life that you will occassionally dig a really deep hole, and find a plough share, horse shoe, large nail, or something equally indesirable.

[Max]

Yes Max, I agree with you. Very same behavior with G.Sabre....
Comparing with Classic 3....much better, neat design this Tesoro, but lacks few things...Almost every model of Tesoro has some drawback.....But looking overall very interesting,nice machines!
I was thinking to combine from few of them and project kind of hybrid without drawbacks you mentioned....
Looking at Eldorado.....well, very simillar to G.Sabre.....
But Silver Sabre is most interesting to me, a slice better audio, but i've change it with 4N35 and 555 anyway....
Notch is very good option, but i can live without it, due less consumption and
smaller pcb.....
So i am planing to take chance with Silver Sabre.....
Only thing interesting me is; is posted schematic accurate? Anybody know?

About G.Sabre; it is enough good to keep it. I intend to take it on the real field again these days, i made anothe DD coil. Now it is working very,very good...
I do advice anybody interested to build it.It is worth of doing...!

Darko, varnish layers can go from 0.01 to 0.05mm....so far as i seen...
So if you want 0.3mm less mistake would be if you take 0.33mm as Max told you!
Also you may relly on resistance when finich coil....to compare with original..
Regards!

Hi ivconic,
"Very same behavior with G.Sabre...." do you mean that also using notch disc it can't avoid iron detection on big masses ? Right ?

If it is so...well there must be for sure an error in design I think.

I agree , anyway, that they all are really good designed machines...also if some lacks are present. I still consider bandido II umax a very good design although have this strange iron response sometimes. And also other models seems to me very hard-worked machines...that have involved much time in testing experimenting for better solutions.
The central nucleus of many tesoro's designs e.g. umax series seems the same and variants are around audio stage...chopper/samplers (fet or 4066)...
battery tester...etc but DISC/GEB structure is close one to another although components are different and functions also could be implemented in various ways. Cause maybe there are rock-solid ideas of what disc/geb channels need to work (phase shifts). I think that also newer ones have similar ideas inside...just with a bit more stuff of microcontrollers and displays.

Tesoro are to me, generally speaking, really good designs.

Best regards,
Max

[Max]

Yes Max, I agree with you. Very same behavior with G.Sabre....
Comparing with Classic 3....much better, neat design this Tesoro, but lacks few things...Almost every model of Tesoro has some drawback.....But looking overall very interesting,nice machines!
I was thinking to combine from few of them and project kind of hybrid without drawbacks you mentioned....
Looking at Eldorado.....well, very simillar to G.Sabre.....
But Silver Sabre is most interesting to me, a slice better audio, but i've change it with 4N35 and 555 anyway....
Notch is very good option, but i can live without it, due less consumption and
smaller pcb.....
So i am planing to take chance with Silver Sabre.....
Only thing interesting me is; is posted schematic accurate? Anybody know?

About G.Sabre; it is enough good to keep it. I intend to take it on the real field again these days, i made anothe DD coil. Now it is working very,very good...
I do advice anybody interested to build it.It is worth of doing...!

Darko, varnish layers can go from 0.01 to 0.05mm....so far as i seen...
So if you want 0.3mm less mistake would be if you take 0.33mm as Max told you!
Also you may relly on resistance when finich coil....to compare with original..
Regards!

Hi ivconic,
nice to ear that your new DD coil works ok ! I'm really stupified of mine cause I get really deeper targets I've buried some time ago to test other machines, pulse induction type.
But yes there are lacks...audio...and then also this strange sensitivity to big iron objects that is not good.
The silver sabre is the best seller of old tesoro's designs and that will be a reason for that...I think it has the best audio of uMax ones.
The eldorado is claimed to be the best in hi-mineralized soil and good for coinshoting. I've found many post in other forums that talk about LOBO too very well for finding coins and relics with good disc but haven't the schematic...and never used it so I can't say nothing sure about.
Quiaozhi told me that with bandido one get signals with big iron masses due to the fact that there is much perturbation on field lines...and that's is true I think but a problem must be there cause also is distorted much lines there is always the phase info to get a useful disc out of iron...
What to say...seems that small asymm in disc stage could cause big iron to be detected easy by bandido II and other models e.g. golden sabre think are the same cause share with it some of these circuit parts.
I'll investigate how to solve (if possible) this behaviour but seems a big task
not so easy.
At first I thinked that coil must be involved but then noticed that concentric and DD give same behaviour with big iron...then realized that no big differences due to coils, just abrupt sound with DD when iron present due to different field lines distribution in the space.

Best regards,
Max

[ivconic]

Truth!

Yes Max, I agree with you. Very same behavior with G.Sabre....
Comparing with Classic 3....much better, neat design this Tesoro, but lacks few things...Almost every model of Tesoro has some drawback.....But looking overall very interesting,nice machines!
I was thinking to combine from few of them and project kind of hybrid without drawbacks you mentioned....
Looking at Eldorado.....well, very simillar to G.Sabre.....
But Silver Sabre is most interesting to me, a slice better audio, but i've change it with 4N35 and 555 anyway....
Notch is very good option, but i can live without it, due less consumption and
smaller pcb.....
So i am planing to take chance with Silver Sabre.....
Only thing interesting me is; is posted schematic accurate? Anybody know?

About G.Sabre; it is enough good to keep it. I intend to take it on the real field again these days, i made anothe DD coil. Now it is working very,very good...
I do advice anybody interested to build it.It is worth of doing...!

Darko, varnish layers can go from 0.01 to 0.05mm....so far as i seen...
So if you want 0.3mm less mistake would be if you take 0.33mm as Max told you!
Also you may relly on resistance when finich coil....to compare with original..
Regards!

[Darko]

Hi,
it's not a stupid question. When I say 0.30mm I mean without varnish. Anyway, it's not so big difference as with smaller gauges cause here varnish dimension of layer is smaller than in smaller gauges.
The wire I've used have 0.30 without and 0.33 with varnish diameter. I've measured with a micrometer.
To remove varnish I use a very powerful solvent that easy melt the thin layer and then I pass over the wire a paper towel without much force applied to avoid stretching the copper.

Best regards,
Max

Thank you, Max.
Best regards,
Darko.

[Max]

How I need to measure dimension of the wire to get 0,30mm? Sorry if this is stupid question but I sow here data of dimensions with varnish and without it. Sorry for my bad English too.

Hi,
it's not a stupid question. When I say 0.30mm I mean without varnish. Anyway, it's not so big difference as with smaller gauges cause here varnish dimension of layer is smaller than in smaller gauges.
The wire I've used have 0.30 without and 0.33 with varnish diameter. I've measured with a micrometer.
To remove varnish I use a very powerful solvent that easy melt the thin layer and then I pass over the wire a paper towel without much force applied to avoid stretching the copper.

Best regards,
Max

[Darko]

About coil : my DD seems fine and I use for both tx and rx 0.30 wire - same turns. Can detect
1 eur at 30cm in ground.

Best regards,
Max

How I need to measure dimension of the wire to get 0,30mm? Sorry if this is stupid question but I sow here data of dimensions with varnish and without it. Sorry for my bad English too.

[Max]

Found problem!!
Yes detector is very good, also my coils!!! Huh!
Problem is in audio! Checked with earphones on same field and it showed again great depth and very good results!
Now have to mod this weak audio....
Or to change power supply....? Dont know yet....
I'll try both...
regards!

Hi ivconic,
yes right audio is poor on these devices...I've tested on my homemade bandido every kind
of speaker I have ... 8 ohm, 16ohm, 20 ohm ...etc etc with different diameter too...
Only two passed the "test":
- a 16ohm speaker (that came from an old apple computer) , about 8cm in diameter
everything smaller gives ugly results !
I have also good audio when used 12cm diameter speaker...but it's not so easy to fit in
any container this kind of stuff...
Anyway, with the "APPLE" speaker, 16ohm, I have very nice sound !
Also you need good headphones set to get it work at best...cause light ones and poor
quality gives bad results with that audio stage.
Problem is not only in speakers / headphones...is the threshold section that make me crazy
sometimes...cause it's deisgned to give stable output with low hum but have big drawbacks:
- when signal from object is low this stuff simply gives a very weak output
I've tested some spare transistors to figure out if problem is related to their gain in output
stage...but no change...signal is weak from IC3B when signal of object is weak cause it's at
more deep !
And auto-tune/disc make things go even worse ! response time is sometimes too fast that you
need to move faster the coil to detect objects; other times seems slower ! It depends on target
depth and soil oxides ...it's a bad news, I know.
The stupid thing in bandido is that in silent mode (disc) you haven't any sound...so why need
having the same stupid threshold amplifier where we can use another approach much more
productive and relaxing ?????? (question is for tesoro's engineers/designers)
My answer to question above is that:
they thinked they must mantain threshold detection also in disc mode to give more informations
to the user--> weak sound means deeper target or really small signal e.g. from a fragment of tin foil.
If was so...it was a really stupid idea...cause we lose targets this way !
On current, yes, it's true that consumption is high also on bandido with speaker. They used
this stuff cause mostly you need silent search...so not much battery drain this way...but when
you have sound current drawn doubles...on bandido is the same stuff.
I suggest using it in silent mode (disc) instead of all-metal auto...or just put the hum level
very low to avoid too much drain.
Important is that you first ground balance very well...this way you avoid much falsing and
get deeper targets more easy - but yes you can miss some coin due to bad audio.
About coil : my DD seems fine and I use for both tx and rx 0.30 wire - same turns. Can detect
1 eur at 30cm in ground.

Best regards,
Max

[ivconic]

Found a problem!!!


Found problem!!
Yes detector is very good, also my coils!!! Huh!
Problem is in audio! Checked with earphones on same field and it showed again great depth and very good results!
Now have to mod this weak audio....
Or to change power supply....? Dont know yet....
I'll try both...
regards!

[ivconic]

Nobodys perfect...!



Nothing is perfect! I spend few days on real field testing G.Sabre....Not so satisfied as i expected to be!
Problem is mostly in coils, although device have weak audio too, so i am not sure where exactly is problem. It would be much more easier if i have original coil....
Detection is deep in the air, but in ground it decreases, mostly cose audio is very weak so it is great chance to miss coin...It need to walk very slow with very slow motions not to miss item in the ground. But some fields need faster examinations...
I am not so sure in coils i made. Already showed excellent performances in the air and on my test field? But on the REAL field ...?? Huh!
For example if coin is at 25cm depth; until 10cm audio is loud and clear (no chance to miss it), but over 10cm audio decreases fast up to 25cm....At the end i have situation to doubt in signal; is it ground hum or detection?
I lost some nervs and smashed small coil!!! Heh,heh.....**** it! I'll make another!

One more thing bugs me; is it right to use same wire gauge for TX and RX???

So far i never saw coil like that, i mean original coil...? It is always thinner wire for RX and thicker for TX...?
Inductances and resistances are close...so i can not picture in my head how to gain those with same wire gauge and make proper coil???
All coils i made are workable....but in real conditions very average....Sheesh!
Is it because of coils or audio???
I am thinking to make Silver Sabre....I think problem is in power supply.
Also noticed that audio at full detection drains to much power....
25mA with no detection and 45mA at full detection...? Too much for my taste!

It is probably because -voltage is generated in "old fashion way", with chopper close related to main oscill.
I think 7660 is much better solution...as in Silver Sabre..? Am i right?
So audio drains too much current and "pull" voltage lower than normal....and thats how affects the rest of electronics in device.....?
Maybe i am right...maybe not? Any suggestions?
regards!

[Darko]

Thanks Stujas and Ivconic for help!