TESORO GOLDEN SABRE

[Max]

Hello,
Max.What are the number of turns for this 12OO coil?
40cm is very good depth!!!
When I nuled my 22 cm DD coil using 200mV range of my multimeter the depth is good,but no disc at all!!!I null to 0,01!
Why is this happening?
Thanks

Hi,
for 12OO you can use:

WIRE 0.25mm/30AWG (0.28 with varnish)
TX turns 145
RX turns 155

but tuning is absolutely critical...so... you can get them work easy but is very difficault get maximum depth from that design on e.g. golden sabre (at least for me... at now! on bandido I get very good results with that)

for Ivconic's 255x137mm DD

WIRE 0.25mm/30AWG (0.28 with varnish)
TX turns 100
RX turns 105

Numbers can vary if you don't use right formers or wire...stay close to that or you have to find new by yourself to match inductance and resistance.

Nulling is always critical for VLF coils... some coils more than others you can use multimeter but it's very hard make repeatable results with that only.

Best regards,
Max

[tiktak]

Hi,

Ivconic,
What is this second trimer in original design and how should it be adjusted?
Thanks

Hi

Ivconic,
I have wind this DD 255X137 with you first data 102 TX and 108 RX!
Maybe thats why I cant get the same results , now I see you give 100 TX and 105 RX!

Hello

Hello,
Max.What are the number of turns for this 12OO coil?
40cm is very good depth!!!
When I nuled my 22 cm DD coil using 200mV range of my multimeter the depth is good,but no disc at all!!!I null to 0,01!
Why is this happening?
Thanks

[Max]

Yes i was thinking the same too; must be noise from switching fets!
But i am thinking must be some other way to "choke" those? To couple with some capacitor, small capacitance, just to blank "sparking"...
Not sure about values yet. Some cap on drain or source.....Any ideas?
My latest TGSL is working like hell in Disc mode. Absoulutely calm and very deep! Even i am suprised! But in All metal mode something strange is happening; when no metal in coil proximity all is calm,silence and stabille but once i cross with coin over coil, TGSL is starting singing and not stoping when coin put away!? I have to switch it off or touch coil with hand to stop it.Again it remains calm until next movement? Coil is superb...it is something again in device? But when switched in Disc mode no problem at all; it is working so good....i dont have words...
Must be those fets!? Must be some way to fix this? Coil and cable are not sensitive at all on touching,moving,"torturing"...remains calm without false signals at all....Very,very good!! 3cm coin over 40cm in the air...
Max sorry i didnt answer you; yes i think TGSL must detect jar with 220 silver coins at 60cm buried in the ground.According to results i gained so far i am 100% sure it will detect those with no effort at all...
Regards!

Hi Ivconic,
nice to see your last is very good on depth. I noticed similar effect on mine just one time... I mean in disc mode worked very nice, then switching to all metal I get strange bleeping that confused me after nearing the target.

In my case it was due to the coil-cable wiring cause I was testing just a return-gnd wire from coil to pcb... probably some kind of twisted pair effect or similar.... then some saturation/closed-loop-signal in the circuit happened I think.

I changed the cable using separate conductors for both coils (like in the tesoro's original coil I've bought) and things become quiet in all-metal too.

I'm not sure that your problem could be there, cause you reported that moving cable give no signal... but I suggest you recheck coil wirings.

Other possible cause in the circuit:

If problem is in the circuit it could be related also to capacitors used I think... e.g. some dried electrolytic in the signal path could give such kind of problems too cause they have bigger ESR... and then losses... so when one of this charge the decay ratio could be higher than other caps. giving confusing/erratic behaviour.

That could happen with new/shelf parts too... cause electrolytics dry also if unused for some years. If you have used shelf/new parts check them with an ESR meter if you have it or just change with new ... expecially in the "bipolar" section.

Actually I got last week new from store parts with hi-ESR and had to complain with guys at store cause one expect new parts are new... not years old products they sell as "new" (never used). But they (poor of electronic concepts) don't even understand well problems related to ESR... so I've decided not buy capacitors anymore at their shop to solve my ESR issues and avoid other troubles.

Best regards,
Max

[ivconic]

H

Yes i was thinking the same too; must be noise from switching fets!
But i am thinking must be some other way to "choke" those? To couple with some capacitor, small capacitance, just to blank "sparking"...
Not sure about values yet. Some cap on drain or source.....Any ideas?
My latest TGSL is working like hell in Disc mode. Absoulutely calm and very deep! Even i am suprised! But in All metal mode something strange is happening; when no metal in coil proximity all is calm,silence and stabille but once i cross with coin over coil, TGSL is starting singing and not stoping when coin put away!? I have to switch it off or touch coil with hand to stop it.Again it remains calm until next movement? Coil is superb...it is something again in device? But when switched in Disc mode no problem at all; it is working so good....i dont have words...
Must be those fets!? Must be some way to fix this? Coil and cable are not sensitive at all on touching,moving,"torturing"...remains calm without false signals at all....Very,very good!! 3cm coin over 40cm in the air...
Max sorry i didnt answer you; yes i think TGSL must detect jar with 220 silver coins at 60cm buried in the ground.According to results i gained so far i am 100% sure it will detect those with no effort at all...
Regards!

[ApBerg]

Hello Friends.

Put a 6N8 cap after the 100K (R30,R2 comming from the switching fet
Made it very quiet, but also the sens is going back....?

If I trace the scopeprobe near the fets they give a lot extrnal noise, can this give problems for the nearby LM 358 ? Input pin 3 and 5.
Also the bandido has caps on those inputs.

Best regards.

Ap

[ivconic]

!

Ap Berg, try this; Sense at 80%, Disc at 10%, Disc mode ON....Should work calm without false signals....
Thanks for tip!
Best regards!

[Max]

Hello Max.

Well.... there was, for some 40 minutes, no erratic sound, then suddenly it became erratic again , just like it was triggerd by something.
The power was the same, near the coil was nothing moving !
It is more quiet but there is still something that makes the golden, at full sens, instabel. Reducing the sens a little solves the problem...and it stays very sensible, ....

Let us know your results !

Best regards.

Ap

Hi,
yes I had tested right now... seems ok for now... are about 15minutes up and running very quiet.

I've solved before the almost (about) all of erratic bleeping changing the TL062 with a TLC2262 that's much better there and are also better than this ic but I have 2262 now. If you have still the TL062 change it for something better low noise dual op amp, TLC2262 is good for that.

About LM308 N version is ok for testing and working too but I still think, as Ivconic reported, that H-version are rock-solid for absolute stability issues.

Problem is that they aren't easy to find and cost much... so not a general solution to the problem.

About the cache-test... from your experience, do you think it could detect the jar of 220 silver coins at 60cm depth ?

Best regards,
Max

[ApBerg]

LM308

Hello Max.

Well.... there was, for some 40 minutes, no erratic sound, then suddenly it became erratic again , just like it was triggerd by something.
The power was the same, near the coil was nothing moving !
It is more quiet but there is still something that makes the golden, at full sens, instabel. Reducing the sens a little solves the problem...and it stays very sensible, ....

Let us know your results !

Best regards.

Ap

[Max]

Ivica wrote :
I made 12 TGSL's so far.All working nice! But have noticed minor differences among them; some of them can produce ocassional,very short false signals....all checked with same coil...It is not coming from coil but from device itself?? What should be a problem. I lost myself in soldering all those pcb's....Need hint on which stage should pay most of attention about stabillity....

Hello Ivica.

Have received the LM308N I had bought in Hong Kong (see mail Esteban) so now made some test. It looks like you can make some improvement if you chance the freq. comp.
for the LM308, I removed the 100 pf caps(C22-C30)and made the freq comp. by placing a 18 pf cap on pins 1 and 8. When you make the boost switch ( 1M resistor) the sound stays quiet, no erretic noise ! Caps from 8.2 pF made a large reduce in sens.
Can be that the value need some more experiments.

Succes.

Ap

Hi ApBerg,
thanks for the hint ... I'll test too.

Best regards,
Max

[ApBerg]

LM308N

Ivica wrote :
I made 12 TGSL's so far.All working nice! But have noticed minor differences among them; some of them can produce ocassional,very short false signals....all checked with same coil...It is not coming from coil but from device itself?? What should be a problem. I lost myself in soldering all those pcb's....Need hint on which stage should pay most of attention about stabillity....

Hello Ivica.

Have received the LM308N I had bought in Hong Kong (see mail Esteban) so now made some test. It looks like you can make some improvement if you chance the freq. comp.
for the LM308, I removed the 100 pf caps(C22-C30)and made the freq comp. by placing a 18 pf cap on pins 1 and 8. When you make the boost switch ( 1M resistor) the sound stays quiet, no erretic noise ! Caps from 8.2 pF made a large reduce in sens.
Can be that the value need some more experiments.

Succes.

Ap

[Max]

a strange idea for a challenge

Hi Ivconic and all,
I was thinking last evening a thing... well I'm not sure of that... anyway that's the idea/thought:

Can the TGS or TGSL with large coil like this DD255x137mm halves win the Carl's cache-test ?

I mean detect a jar full of e.g. silver coins at 24 inches deep.

I think it can do that: 24 inches are about 60cm... and if you consider using neutral soil (easy) with not too much iron-crystals I strongly think it can do that... in spit of all of the "top of the range" thousands dollars deep-seekers that actually can't !

Ivconic what do you think ? Is that possible for you ?
For me it is possible using easy/neutral soil.

I haven't the 220 silver coins to run the test myself but maybe someone has already and can do the test for 24'' detection.

Also I'm not truly interested in testing that... but I read something that cache-test is impossible to be passed by MDs... and just wonder of one saying that... cause I/we know good PI can do that... but till now maybe nobody proved it true with an IB/VLF (true discriminating) machine, like TGS is !

Any idea ?

Kind regards,
Max

[Max]

"Have you find the LM308?"
Actually Strujas gave me LM308H (metal case). Indeed you were right!
Better relation S/N! I suggest now LM308H to be used!
Short anecdote:
I was in a hurry to test those so soldered few wrong way!!!
Started to count pins from small notch!!! So pin under notch was "1"!!!
When switched ON TGSL started screaming pretty loud. I was confused.
First thought was "it cant replace LM308N..."! Damn!
Later dug out what was the problem. I was 100% sure those are burned!
What a waste! But "small warm" in my head pushed me to correct and replace
pins in proper manner (same ic's). Again tried and.....working!Hurraahh!!
Not burned! Alive, and working pretty good! Miracle!
SO PAY ATTENTION FOLKS! UNDER NOTCH THERE IS PIN NUMBER 8 , NOT 1 !!!
This can happen only to people like me....not to smart people!

"Got 5.62 mH inductance, giving me a freq. of 14.69Khz on TGS, R=23.1ohm !"
Max i made same coil twice. First with 0.25mm and second with 0.3mm, just for
comparsions. Have a feeling that one with 0.3mm is a bit better!?
I suggest you to do the same and later post here your remarks, please.
Of course, number of windigs should be corrected a bit...few more for both coils.
You will gain less resistance of course. But those will work fine even resistances
are down to 18 ohms approx. No worries.

"A picture is better than 1000 words."
You got that right! I agree. Photos you posted giving me exact picture of your work.
That coil will work very good!

"I wish to you good works.."
Giasou Geo! Pou ise? Ti kannis? Kala..?
Long time no words from you Geo. Nice to have you back!
"A Guy from Bulgaria ..."
Yes i conntacted him. 27cm cost 4.6e in Sofia shop. Less than i payed for those my housings.
But when calculating shipment,post taxes, maybe some custom taxes......prices will be
leveled for me....Other thing is that his housings are made from pure plastic, but my
i ordered to be made from fiberglass - pretty stiff, no jitters later. Although i
recommend those Bulgarian coil housings too! Had few in the past - very good!

"THat's astounding. I wish you the best of luck in hounding, er, convincing your "almost"
suppliers into providing your needs."
To tell you the truth; money is most convincing thing on this world!
Again Max, nice work! If i had such sharp camera as yours!

About cigars; ehm, all those antismoking campaigns initially came from USA! Land of Marlboro,
Lucky Strike.....and much more brands!? I dont understand this? I am smoker. If i get cancer
than it is my problem.Why all those people are trying to stop me, limit me,prohibit me...?
What about other bad things arround us? Smokers or not,USA comes on the top of the list with
most of cancer deseases....How come? Such nice American way of living, helth,gyms,beauty saloons,
"ugly is forbidden"...Huh, i should stop! This is not subject here! Sorry!
RObert is back, we meet ocassionaly. His influence on me is obvious! Sheeesh!

P.S. Just to add; remeber Michael Moore? The smartest,most human,most funny American i ever
saw in my life! Long live to Michael! Personally i would like to meet him and express
my admiration to him and his work! If anybody of you know him, please pass the very best
regards from me!

Hi Ivconic,
yes works very good, tested just 30minutes ago... and still wonder of how good it is.

Got 1eur coin at 36cm easy on air on the test bench just keeping halves fixed with tape on a flat board !

Very good. The half-crown (that is 32.5 mm diameter) at much more maybe 40 who knows ? I haven't measured at all... just too amazed by results.

Nulling is (at now) around 4.5mVpp very hard to get cause tape is no good for that torsion forces on bigger coil and have to use much for test to keep them aligned.

Now... the big problem for me is applying a right shield (they are now actually unshielded) puzzled between what to use this time... wanna use mylar but have few... ad don't know if good idea ... maybe I'll use a bad kitchen roll, very thin al.... and of course... finding a right coil-housing to seal it.

I'm very happy with results and suggest anyone here build this configuration for a good compromise between coil dimension and depth.

Of course... I've done nulling smoking the Che's cigar... but that's obvious.

Best regards,
Max

PS. I'll test 0.30mm wire... but at now I haven't... run out of it and used 30AWG for halves. Have to find at least 150meters to perform the test... I think also could give better results than 30AWG.

[ivconic]

MM

"Have you find the LM308?"
Actually Strujas gave me LM308H (metal case). Indeed you were right!
Better relation S/N! I suggest now LM308H to be used!
Short anecdote:
I was in a hurry to test those so soldered few wrong way!!!
Started to count pins from small notch!!! So pin under notch was "1"!!!
When switched ON TGSL started screaming pretty loud. I was confused.
First thought was "it cant replace LM308N..."! Damn!
Later dug out what was the problem. I was 100% sure those are burned!
What a waste! But "small warm" in my head pushed me to correct and replace
pins in proper manner (same ic's). Again tried and.....working!Hurraahh!!
Not burned! Alive, and working pretty good! Miracle!
SO PAY ATTENTION FOLKS! UNDER NOTCH THERE IS PIN NUMBER 8 , NOT 1 !!!
This can happen only to people like me....not to smart people!

"Got 5.62 mH inductance, giving me a freq. of 14.69Khz on TGS, R=23.1ohm !"
Max i made same coil twice. First with 0.25mm and second with 0.3mm, just for
comparsions. Have a feeling that one with 0.3mm is a bit better!?
I suggest you to do the same and later post here your remarks, please.
Of course, number of windigs should be corrected a bit...few more for both coils.
You will gain less resistance of course. But those will work fine even resistances
are down to 18 ohms approx. No worries.

"A picture is better than 1000 words."
You got that right! I agree. Photos you posted giving me exact picture of your work.
That coil will work very good!

"I wish to you good works.."
Giasou Geo! Pou ise? Ti kannis? Kala..?
Long time no words from you Geo. Nice to have you back!
"A Guy from Bulgaria ..."
Yes i conntacted him. 27cm cost 4.6e in Sofia shop. Less than i payed for those my housings.
But when calculating shipment,post taxes, maybe some custom taxes......prices will be
leveled for me....Other thing is that his housings are made from pure plastic, but my
i ordered to be made from fiberglass - pretty stiff, no jitters later. Although i
recommend those Bulgarian coil housings too! Had few in the past - very good!

"THat's astounding. I wish you the best of luck in hounding, er, convincing your "almost"
suppliers into providing your needs."
To tell you the truth; money is most convincing thing on this world!
Again Max, nice work! If i had such sharp camera as yours!

About cigars; ehm, all those antismoking campaigns initially came from USA! Land of Marlboro,
Lucky Strike.....and much more brands!? I dont understand this? I am smoker. If i get cancer
than it is my problem.Why all those people are trying to stop me, limit me,prohibit me...?
What about other bad things arround us? Smokers or not,USA comes on the top of the list with
most of cancer deseases....How come? Such nice American way of living, helth,gyms,beauty saloons,
"ugly is forbidden"...Huh, i should stop! This is not subject here! Sorry!
RObert is back, we meet ocassionaly. His influence on me is obvious! Sheeesh!

P.S. Just to add; remeber Michael Moore? The smartest,most human,most funny American i ever
saw in my life! Long live to Michael! Personally i would like to meet him and express
my admiration to him and his work! If anybody of you know him, please pass the very best
regards from me!