TESORO GOLDEN SABRE

[ivconic]

...


I made pcb 128x100mm...Not stated in posted document so i have to scale it just to fit ic's; at the end it was 128x100mm...although this maybe not original but suits just fine.

Today i made several tests on the ground in real conditions, with smaller coil.
Yes detection is much deeper than i expected at first time.
I took several coins, but different material; brass,Al,Aq,Au,Cu and burried them at 10cm depth. All detected. Than at 15cm - all detected, than at 20cm...than i noticed some variations in audio tone. Than at 25cm; Ag and Cu were detected easy and with clear strong tone. Au not detected, Al very poor with mum tone. Than at 30cm; Ag detected with weak tone, Cu not detected....
Not to mention iron; iron piece 5x5cm detected at 45cm in the ground very clear with loud tone.
etc.etc.....
I noticed also,in disc mode, at the very end of foil detection,just about to reject foil, it cant detect coins clear but with broken sound, so there is danger to skip some coins if foil is rejected....It must be something about this coil....still not proper...Maybe need some corrections....
When sens is full, in All metal mode sometimes i can hear very weak "tic,tic.."
in speaker...but not so often; later when switch in Disc mode it stops permanently; calm and very stabile! Good! Anyway, when coinshooting i almost always run detector in Disc mode, never in all metal...
Still not tested larger coil on the ground cose dont have case for it. Wait to finish it than intend to test it....
Regards!

[ivconic]

More...


Forgot something!
Golden Sabre is very good, but audio is poor. I am thinking somehow to mod it. Any tip?
I was thinking if there is some way to add two tone...BUT not as usuall in earlier cases, but separate tones, one for All metal mode, other for Disc....or even better; in Disc mode, low tone for iron and high pitched tone for coloured metals.....like in CScopes....
Any ideas?

[Geo]

Hi Ivica.
Now i am at Athens (i don't work with my pc so i can't see any schematic).
But 2x 4N35...2x555 and 1 LM386 will give two tones with very strong sound.
Regards

[Darko]

Hi Ivica!

Pridruzujem se cestitkama! Congratulations!

I'll also try to make GoldenSabre in future but i need some help with componnent list. In shematic of Golden,there is a some caps with values around pF.Can I use ceramic caps for this values?

>>>>I noticed also,in disc mode, at the very end of foil detection,just about to reject foil, it cant detect coins clear but with broken sound, so there is danger to skip some coins if foil is rejected....It must be something about this coil....still not proper...Maybe need some corrections....

Also my just finished cl3 doo that.Coil is small Spider,shild connected to TX.And when I move DISC pot just little above this of point then cl3 detect only big targets!This coil i have was opened earlier and maybe this happens cose shilding is not anymore good.Or i not make propper adjustemets of cl3.Are is too difficult to adjust GoldenSabre?

Regards,
Darko

[Max]

Forgot something!
Golden Sabre is very good, but audio is poor. I am thinking somehow to mod it. Any tip?
I was thinking if there is some way to add two tone...BUT not as usuall in earlier cases, but separate tones, one for All metal mode, other for Disc....or even better; in Disc mode, low tone for iron and high pitched tone for coloured metals.....like in CScopes....
Any ideas?

Hi ivconic,
very good ! Your tests confirm that it's a good general purpose detector and really good for coinshooting purposes. I'm awaiting for 9x8 coil to test in ground conditions with bandido and think that maybe I could made an OO coil too like yours.
If I remeber well it was 12+12cm diameters with about 150-170 turns to get 10KHz. I'll try this design asap.
For two tones...I think that like in bandido is possible to add using op amps and giving a useful signal from the end of disc channels. Cause there are two signals there we need something like a diff. integrator I think.
Then something to get tones...but maybe there are other frequencies on cmos counter that one could use to get a lower tone - I think so.
Yes the CScopes behaviour would be good feature on it - just I think one must add this feature with a switch to enable it or not during searching.
Just one must take care on consumption too...so maybe a low consumption amplifier is required to avoid too load on voltage converter and also a good tone generator or something similar.

Best regards,
Max

[strujas]

Hi Ivica!

Pridruzujem se cestitkama! Congratulations!

I'll also try to make GoldenSabre in future but i need some help with componnent list. In shematic of Golden,there is a some caps with values around pF.Can I use ceramic caps for this values?

>>>>I noticed also,in disc mode, at the very end of foil detection,just about to reject foil, it cant detect coins clear but with broken sound, so there is danger to skip some coins if foil is rejected....It must be something about this coil....still not proper...Maybe need some corrections....

Also my just finished cl3 doo that.Coil is small Spider,shild connected to TX.And when I move DISC pot just little above this of point then cl3 detect only big targets!This coil i have was opened earlier and maybe this happens cose shilding is not anymore good.Or i not make propper adjustemets of cl3.Are is too difficult to adjust GoldenSabre?

Regards,
Darko

Mozes koristiti keramicke ali troslojne one sa 1% tolerancije ......

[ivconic]

...


Yes Geo, but how to connect those on existing setup? It will need some "inetgrator" or something simillar to "decide" which sound will be used at that particular moment...low for iron or high for coloured....
I dont have schematic of CScope 1220B, i would like to see it, cose its audio is really what i am looking for..Anybody have that? If dont want to post whole schematic, please just post audio stage here...

Ja sam stavio keramicke reda pF....mada i Andrija je u pravu (Strujas)...
I put ceramic capacitors although Strujas is also right....

Max if want double O coil, than yes it is 12cm radius, about number of turns...well you have to recalculate it, also dependable of wire gauge....

I just started making another coil, but this time double D coil, with 18cm diamm.....just observing TS 800 (Minelab) coil and trying to keep same shape and look.....heh,heh,heh !!!

When finish it i'll post photo, but only if it works...
Regards!

[ivconic]

TS 800...Ts...ts..ts !!!


FINALLY !!! (capitals...ts,ts,ts...must be a crackpot?)
Finally i made coil,i always wanted to make!
But first i'll name conditions for "dream coil";
- It has to be small, smallest as could be!
- It has to be round, due comfort in movements,
- It has to be very sensitive on small (very small) items,
- It has to be deep....and I MEAN DEEP !
Only one coil i met so far fullfilling those requirements;
it was Minelab TS 800 coil (18cm)
1cm coin (i usually use for testing coils) it can detect at 22cm
in the air and 18cm in the ground!
So......
I made Golden Sabre and it showed pretty good performances with
two "casual" coils i made fast - "on the fly", last few days...
Yesterday i took TS 800 coil and redraw its shapes on plain paper...
And i done some calculations and made BEST coil so far...!!!
It is double D coil.....here is datas so you can make, test and
check my claims:
RX = 178 turns, 0.25mm wire (0.28mm with varnish), 23,6 ohms
TX = 165 turns, 0.25mm wire (0.28mm with varnish), 21,4 ohms
How can i explain former...? Huh? Here is photo of it. Diammeter of
whole coil (both DD shapes put togather,tuned and nulled) is 18.5cm...
so try to imagine how to make former...
I used Al foil for both coils as Faraday cage. Over foil i wounded
few windings with plain, naked (without varnish) wire to make good
conntact with foil. Over all i wraped simple adhesive tape to
consolidate, brace all...and that is all!
The rest, about nulling....you already know, i do not need to repeat here.
Coil performances are ....WOW !
Same coin it detecting over 30cm in the air!!!!! Much better than TS 800!!!
Cigarretes package at 45cm, cola can over 52cm.....
For coin:
Up to 25cm audio tone is loud,sharp and stiff!!! Over 25cm audio tone is
decaying step by step and a bit over 30cm it ends....WOW !!!
(up to 25cm constant flux, over 25cm it decreases....read bellow)

Promising....promising!
I'll have to wait until tomorow to test it on the ground. Few more steps left
to finish it; put in some suitable case,glue it...wait until drain...get dry...

I think i discovered "big secret" about coils...somehow...!?
Problem about depth is not closely related only to size of a coil. Much more
important thing is flux, magnetic flux! Density of magnetic field that TX
part producing...
It is not immaterial relation between size of a coil and wire gauge used in it!
How can i explain?
The higher density of magnetic field coil is producing - the better!
If choosing proper wire gauge than no need for much power on TX. Simple 2N2907
can do the job just fine. BC557 also.
Unlike in Anker detector and simillars, you dont need extra powerfull TX to gain
some depth! No not at all! Even oposite, powerfull TX is more like to "choke"
RX input and than another problem occurs - hums,false signals,interferences....
Totally unusable on the ground, especially on highly mineralized ones!
At the end, frequency is playing huge role when deciding about coil size and wire
gauge....I had luck (must admit) with this Golden Sabre, due its 14kHz frequency!
In the past i had a lot of "pains" and troubles trying to make Classic 3 go deeper
with small coils....no wonder!
So at the end conclusion;
"Larger" flux could be gained if preciselly chosen wire gauge and coil diammeter.
How to do that?
I dont know!
I dont have a clue!
I just had luck, this time!
Heh,heh,heh...!
Best regards!

[Max]

FINALLY !!! (capitals...ts,ts,ts...must be a crackpot?)
Finally i made coil,i always wanted to make!
But first i'll name conditions for "dream coil";
- It has to be small, smallest as could be!
- It has to be round, due comfort in movements,
- It has to be very sensitive on small (very small) items,
- It has to be deep....and I MEAN DEEP !
Only one coil i met so far fullfilling those requirements;
it was Minelab TS 800 coil (18cm)
1cm coin (i usually use for testing coils) it can detect at 22cm
in the air and 18cm in the ground!
So......
I made Golden Sabre and it showed pretty good performances with
two "casual" coils i made fast - "on the fly", last few days...
Yesterday i took TS 800 coil and redraw its shapes on plain paper...
And i done some calculations and made BEST coil so far...!!!
It is double D coil.....here is datas so you can make, test and
check my claims:
RX = 178 turns, 0.25mm wire (0.28mm with varnish), 23,6 ohms
TX = 165 turns, 0.25mm wire (0.28mm with varnish), 21,4 ohms
How can i explain former...? Huh? Here is photo of it. Diammeter of
whole coil (both DD shapes put togather,tuned and nulled) is 18.5cm...
so try to imagine how to make former...
I used Al foil for both coils as Faraday cage. Over foil i wounded
few windings with plain, naked (without varnish) wire to make good
conntact with foil. Over all i wraped simple adhesive tape to
consolidate, brace all...and that is all!
The rest, about nulling....you already know, i do not need to repeat here.
Coil performances are ....WOW !
Same coin it detecting over 30cm in the air!!!!! Much better than TS 800!!!
Cigarretes package at 45cm, cola can over 52cm.....
For coin:
Up to 25cm audio tone is loud,sharp and stiff!!! Over 25cm audio tone is
decaying step by step and a bit over 30cm it ends....WOW !!!
(up to 25cm constant flux, over 25cm it decreases....read bellow)

Promising....promising!
I'll have to wait until tomorow to test it on the ground. Few more steps left
to finish it; put in some suitable case,glue it...wait until drain...get dry...

I think i discovered "big secret" about coils...somehow...!?
Problem about depth is not closely related only to size of a coil. Much more
important thing is flux, magnetic flux! Density of magnetic field that TX
part producing...
It is not immaterial relation between size of a coil and wire gauge used in it!
How can i explain?
The higher density of magnetic field coil is producing - the better!
If choosing proper wire gauge than no need for much power on TX. Simple 2N2907
can do the job just fine. BC557 also.
Unlike in Anker detector and simillars, you dont need extra powerfull TX to gain
some depth! No not at all! Even oposite, powerfull TX is more like to "choke"
RX input and than another problem occurs - hums,false signals,interferences....
Totally unusable on the ground, especially on highly mineralized ones!
At the end, frequency is playing huge role when deciding about coil size and wire
gauge....I had luck (must admit) with this Golden Sabre, due its 14kHz frequency!
In the past i had a lot of "pains" and troubles trying to make Classic 3 go deeper
with small coils....no wonder!
So at the end conclusion;
"Larger" flux could be gained if preciselly chosen wire gauge and coil diammeter.
How to do that?
I dont know!
I dont have a clue!
I just had luck, this time!
Heh,heh,heh...!
Best regards!

Hi ivconic,
your DD seems is like my homemade...but I've used mylar/al on shielding instead of foil. The other parts are similar...but I've used 120 turns for both tx and rx cause I need 10KHz on bandido. Used rx flat then tx bounced over.
Get very good results in air.
Yes, I think that tx flux is an essential part of success here, but you need to consider than what's truly important is signal-to-noise ratio in this kind of detectors cause power is always limited respect to e.g. pulse induction type.
And the guys at tesoro knows what they do...I mean they used good schematic strategies to improve S/N and also (like in e.g. bandido) "special" components to physically reduce noise at operating frequency. This way they get outstanding performances that mainly depends on coil parameters cause S/N in the circuit is always controlled and stable. So if you use e.g. a DD coil you could get much less problems e.g. from mineralization where using concentric you could get better pinpointing. Also wire gauge is important cause oscillator is small power colpitts and current depends mainly on coil too.
What to say...with proper coils I think that many of these detectors are still actual cause have good performaces in ground and only lacks are in display/mcu that are absent and present e.g. in Cortes or other newer. But they are good...general purpose VLF. So far, bandido is the best VLF I've mounted myself ! I had problems with components at first and with concentric...but it's clear that is a powerful design , really stable with right things in the circuit. And GoldenSabre is much like it - if not better !
I told you that DD works great on bandido...then your GS will appreciate DD too also on the ground I think.


Best regards,
Max

[Darko]

Thanks Stujas and Ivconic for help!

[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!

[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!

[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

[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]

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