TESORO GOLDEN SABRE

[ivconic]

Hello Ivconic , Max . Are all tesoro coils center tapped ??? Also Qiaozhi pointed out , some tesoro coils are designed to be out of phase for pre-discrimination , is this on all Tesoro coils ????...........Thanks ...........Eugene

I really dont know. That is what i intend to establish..sooner or later.

[Aziz]

I was tired today to experiment a bit more. You know what? Now iron is not that hard rejected as with previous coils. With previous coils iron was hard to detect even in All Metal mode.GEB trimmer was approx. at middle point. Disc was "slow", man had to turn it more to up to reject foil. Now, iron is detectable even in Disc mode at "1" to "2", over "2" is rejected totally. Ferrite rod is not detectable any more at all. In both modes turning GEB trimmer fully from minus to plus ferrite rod remains not detectable at all???
1e coin is bairly detectable!? Other hand, nickel is very good detectable!?
Day after tomorrow i am expecting new oscilloscope to get (finally), so i will not perform "wild and blind" experiments any more. Day after tomorrow i will perform full experiments and finally make some conclusions.
Although present situation with center tapped coil is not yet clear, i have strong feeling that it will perform much better than ordinary coil. Why? I cant explain, i just have such strong feeling.
Please give me some suggestions...

P.S. it is obvious that phase is shifted more here... Question is; will be more easy now to GEB it on real soil...or not? Further...those infamous chatters....are those will exist again? So far i think those will exist. It is not about coil, it is about something on pcb...

Center taped RX coil (center connected to ground) will have a better noise rejection on cables. Using the coil in differential mode, the noise typically will be same on the coil cables and on differential mode, they will be subtracted out. This will increase the SNR.

The LC oscillator is heavly loaded (impedance). Maybe a high input impedance op-amp buffer (~100 k) could be used and then fed to the circuit parts. Keeping the LC oscillator loading low will stabilize the LC oscillator.
It could bring some improvements. But the experiment should proof this one day.

Aziz

[Max]

I was tired today to experiment a bit more. You know what? Now iron is not that hard rejected as with previous coils. With previous coils iron was hard to detect even in All Metal mode.GEB trimmer was approx. at middle point. Disc was "slow", man had to turn it more to up to reject foil. Now, iron is detectable even in Disc mode at "1" to "2", over "2" is rejected totally. Ferrite rod is not detectable any more at all. In both modes turning GEB trimmer fully from minus to plus ferrite rod remains not detectable at all???
1e coin is bairly detectable!? Other hand, nickel is very good detectable!?
Day after tomorrow i am expecting new oscilloscope to get (finally), so i will not perform "wild and blind" experiments any more. Day after tomorrow i will perform full experiments and finally make some conclusions.
Although present situation with center tapped coil is not yet clear, i have strong feeling that it will perform much better than ordinary coil. Why? I cant explain, i just have such strong feeling.
Please give me some suggestions...

P.S. it is obvious that phase is shifted more here... Question is; will be more easy now to GEB it on real soil...or not? Further...those infamous chatters....are those will exist again? So far i think those will exist. It is not about coil, it is about something on pcb...

Hi,
don't know... the chatters still could reappear on soil... I hope they will disappear forever... but till now no coil solved them totally. I tested with many coils... like DD22, 9x8'' and the large, usual, 11'' DD as you. With all the TGS form time to time exibit chatters at max sens when on soil... with complete ground balancing.

But I don't tested with center tapped coils....at least I tested with the original 9x8 by tesoro but I don't know if it's center tapped.

I think that sometimes it's due to currents flowing in the soil like where powerlines are involved... but other times the origin is unknown... probably an unknown VLF emission strong enough to make it sound and become instable at max sens. This sure must sum with internal noise that's another big issue.

Maybe the center tapped coil will solve that ? I hope so... will be really a good news just forgetting chatters forever!

Kind regards,
Max

[ivconic]

Trust me, chatters are not coil related and dependant. After 30 coils so far i am free to claim that.
Even now with center tapped coil chatters are present... Not to mention 26 devices so far. Chatters on every one.
Ha,ha...recently i tested original Vaquero - chatters there also!??
What to say?

But what is really strange ; outdoor, on soil, chatters are rare??? Ocassionall.....without any rule??

[Max]

Trust me, chatters are not coil related and dependant. After 30 coils so far i am free to claim that.
Even now with center tapped coil chatters are present... Not to mention 26 devices so far. Chatters on every one.
Ha,ha...recently i tested original Vaquero - chatters there also!??
What to say?

But what is really strange ; outdoor, on soil, chatters are rare??? Ocassionall.....without any rule??

We say the same thing... I mean interferences... outdoor are less... but sometimes make it sing macarena!

I have a couple of places where TGS sings quite well... but are "hot" places: near is a powerful radar complex... and lot of cables in the soil!

So... these are not good examples of neutral soil...

Kind regards,
Max

[simonbaker]

R47, R55

Are R47, R55 (4K7 resistors on final LM393 output) on TGSL 1265 PCB? Don't see them.

Sorry if repeat question . (annoying we can't search small words.)

Cheers!

-SB

[ivconic]

LET THERE BE ROCK !!!

Good thing to add on TGSL is PP mode..so

Let there be rock!

[Max]

Good thing to add on TGSL is PP mode..so

Let there be rock!

Hi,
that's interesting... I think will be the only important feature missed in original design!

I'm doing pinpointers these days...

Found a schematic posted by KT315 of an Automax pinpointer... uhm... I've mounted on perfboard in 30 minutes... and say what ? It works cool!

It get 1 eur at 2inches easy... and more with other stuff... like 2eur coins that's enough for me to say it works just cool!

Just I had to add some mods... and use an guessed coil cause I have no data about!

So... I think I will pack it and use on the field very soon.

If anyone interested I could provide data for coil and other missing parts...

The mod of above is interesting for some new revision of the gift-pack...

Kind regards,
Max

[ivconic]

TGSL + P.P.

Ok now is complete....

[simonbaker]

coil inductance

PP interesting - where did you get circuit?

TGSL not so L any more.

I have a couple of review questions - getting very difficult to search huge thread:

1. What is the "official" inductance of the TX and RX coils for TGSL? Did anyone actually measure Tesoro GS coils? Or has anyone concluded a "best" inductance from experiments?

2. What size wire is OK for RX coil? Is 32 awg OK? Has anyone tried even thinner? From schematic, it seems maybe resistance of RX coil not important (unless we are "on resonance" but Max says no). Why not 40 awg wire?

------------ progress -------------

I made first coil last night - tried to make Ivconic "28" (26.8 ) cm TX DD, but too excited did not follow Max design exactly with bevel corner and overlap area - I made an exact half circle. But I think OK for experiments.

Wire thickness: Measured about .0135 inch (.343 mm) with enamel - 28 awg? - used it anyway, because my other wire is 32 awg.

Coil form: I used approx 27 cm inner diameter (half circle shape). Tried 120 turns but got 7.2 mH (loose) and 18.5 ohms.

Removed turns - now 105 turns, 5.85 mH (tight), 16.3 ohms.

But what is best? I can remove more - do we want 5.45 mH or what? Your wisdom is appreciated.

Interesting experiment: I stretched coil into a circle shape, and then inductance went to 6.31 mH. I put it back to semicircle and it returned to about 5.9 mH.

I will post some pictures later for fun (and show mistakes).

I will start circuit when more parts arrive. Funny, many places not have .22 capacitor, or too expensive, huh? But I find them eventually. Old semiconductors not so easy either.

I will not build final MD right away but rather build circuit for many tests and experiments first.

Cheers,

-SB

P.S. Still cannot find R47, R48 on TGSL-1265 PCB -- not needed?
P.S.S. Can Sprint have another layer for part number?

[Max]

PP interesting - where did you get circuit?

TGSL not so L any more.

I have a couple of review questions - getting very difficult to search huge thread:

1. What is the "official" inductance of the TX and RX coils for TGSL? Did anyone actually measure Tesoro GS coils? Or has anyone concluded a "best" inductance from experiments?

2. What size wire is OK for RX coil? Is 32 awg OK? Has anyone tried even thinner? From schematic, it seems maybe resistance of RX coil not important (unless we are "on resonance" but Max says no). Why not 40 awg wire?

------------ progress -------------

I made first coil last night - tried to make Ivconic "28" (26.8 ) cm TX DD, but too excited did not follow Max design exactly with bevel corner and overlap area - I made an exact half circle. But I think OK for experiments.

Wire thickness: Measured about .0135 inch (.343 mm) with enamel - 28 awg? - used it anyway, because my other wire is 32 awg.

Coil form: I used approx 27 cm inner diameter (half circle shape). Tried 120 turns but got 7.2 mH (loose) and 18.5 ohms.

Removed turns - now 105 turns, 5.85 mH (tight), 16.3 ohms.

But what is best? I can remove more - do we want 5.45 mH or what? Your wisdom is appreciated.

Interesting experiment: I stretched coil into a circle shape, and then inductance went to 6.31 mH. I put it back to semicircle and it returned to about 5.9 mH.

I will post some pictures later for fun (and show mistakes).

I will start circuit when more parts arrive. Funny, many places not have .22 capacitor, or too expensive, huh? But I find them eventually. Old semiconductors not so easy either.

I will not build final MD right away but rather build circuit for many tests and experiments first.

Cheers,

-SB

P.S. Still cannot find R47, R48 on TGSL-1265 PCB -- not needed?
P.S.S. Can Sprint have another layer for part number?

Hi,
my pinpointer is from a KT315's schematic... he draw from reverse eng. of the pcb of automax precision version 2. You can see it in the picture, all by bjts, no ics.

Ivconic followed other tesoro's designs to make the PP mod on TGS! i like it... I made something similar but I think is lost in this thread at unknown page...many months ago... but I never tested it.

The reference inductances are those of uMax coils... you can read some values here: http://geotech.thunting.com/cgi-bin/...oils/index.dat

In concentric there's something 5.6-5.75mH at TX and usually around 6.2mH at RX.

Now... actually we are interested mainly in DD config... but use slight different values about inductances... we get about 5.45mH for TX and 5.6-5.7mH for RX in Ivconic's DD design.

Notice that in tesoro's 11'' DD is something 5.90 at Tx and 5.38 at Rx, but consider also that our DD goes deeper !
With original one 11'' you'll get it run around 14Khz or below... but with our DD here you'll get around 14.6 - 14.69Khz (100 turns).

Kind regards,
Max

[Max]

PS: I forget params for PP

used 120turns for tx, 60 for rx on a 62mm long ferrite rod... like in AM radio.
Wire is 30AWG.

Used then 4700pF for C2 and 1Mohm for the thresh. pot.

For transistors could use anything, I've used BC547/BC557

The zener at vibro stuff depends on voltage of vibro... if 3V use a 5.1V diode.

And works cool!

Kind regards,
Max

[nelson]

Hi MAx.
About the automax pinpointer you build, can you send or post coil details and of course any mods you have made?
My email is [email protected]
In advance many thanks
Regards
Nelson

Hi,
my pinpointer is from a KT315's schematic... he draw from reverse eng. of the pcb of automax precision version 2. You can see it in the picture, all by bjts, no ics.

Ivconic followed other tesoro's designs to make the PP mod on TGS! i like it... I made something similar but I think is lost in this thread at unknown page...many months ago... but I never tested it.

The reference inductances are those of uMax coils... you can read some values here: http://geotech.thunting.com/cgi-bin/...oils/index.dat

In concentric there's something 5.6-5.75mH at TX and usually around 6.2mH at RX.

Now... actually we are interested mainly in DD config... but use slight different values about inductances... we get about 5.45mH for TX and 5.6-5.7mH for RX in Ivconic's DD design.

Notice that in tesoro's 11'' DD is something 5.90 at Tx and 5.38 at Rx, but consider also that our DD goes deeper !
With original one 11'' you'll get it run around 14Khz or below... but with our DD here you'll get around 14.6 - 14.69Khz (100 turns).

Kind regards,
Max

[Max]

Hi MAx.
About the automax pinpointer you build, can you send or post coil details and of course any mods you have made?
My email is [email protected]
In advance many thanks
Regards
Nelson

Hi Nelson,
I posted them in the message above yours... look at it.
Coil is very easy and not critical at all, other turns ratio will work too but I used 120/60 for now.

With that data you can run it at around 100Khz.

Remember that phase is important, so if doesn't work reverse one coil leads.

When you turn it on at first you just need turn the pot till it sounds, then back till just hear small/low cracks or nothing at all... then it's at max sens... and will detect 1eur at about 2''.

It will start cracking at far but nearing object it will rise the tone till strong beep will signal object in really safe way, you can't miss it.

It's good for smaller things too... like nuggets and the like: you need to near it more but can detect 3mm stuff at 4-5mm with a good sound.

Another advantage is that's really stable... you switch it on and off... and works about the same: other PP need constant retuning at each switchon...no good.

Kind regards,
Max

[maxbiri]

Hi Max

For bz1 what i need? a simple piezo or one with oscillator inside?
Diode are 1n4148?

Thanks in advant.

Bye Maxbiri