TESORO GOLDEN SABRE

[simonbaker]

Caps are correct. 3.3K is 3.9K. Diode on LM308 (GND Bal) not there, only other difference is 33k at last LM358, this is 2.2K.

Revised as per above.

Also note that manufacturer's "improve" (or substitute parts) design sometimes so some of these values maybe correct on earlier or later version of TGS.

Simon will try to make scan of pcb (may be difficult as standoffs are soldered to pcb) I Try.

Molzar

Excellent! It increasingly confirms Ivconic's final TGSL design.

I'm sure it is difficult to get good scan of pcb. Perhaps you could try tripod with good digital camera mounted directly opposite pcb held in some kind of vice, exactly perpendicular and in center of camera frame. Try to move camera as far away as possible (3 to 5 feet or more), use maximum zoom. Then same thing for other side, exact same distance. Then maybe write on image any part numbers / values that are not visible.

Also interesting would be same pictures with bright light behind PCB to show shadow of other side at same time.

Just a little project to keep you busy!!! That is a lot of work, so of course we appreciate anything you can do.

On another subject: one mod that I think we should think about is a pot to control the TX oscillator amplitude. Ivconic just killed the feedback circuit to get max amplitude, and he gets best depth, maybe that is partly why. It seems like an important parameter, should be adjustable for us because we don't mass produce, we can tweak. Also need to experiment running oscillator directly off battery -- is it a good idea, or do we need very stable voltage?

Cheers!

-SB

[Molzar]

Caps are correct. 3.3K is 3.9K. Diode on LM308 (GND Bal) not there, only other difference is 33k at last LM358, this is 2.2K.

Revised as per above.

Also note that manufacturer's "improve" (or substitute parts) design sometimes so some of these values maybe correct on earlier or later version of TGS.

Simon will try to make scan of pcb (may be difficult as standoffs are soldered to pcb) I Try.

Molzar

[simonbaker]

think this schematic is without any mustakes
need confirm from Molzar (for those cap`s in picofarads)

Good work!

But I think this schematic still has both diodes on LM308, while PCB apparently has only one?

Let's continue to verify it is exact as much as possible, just so we have an exact reference to the real Tesoro circuit. I tried to match front and back photos of PCB, but difficult to line up exactly due to distortions. I guess Molzar has the ball now...

Regards,

-SB

[Mullihaka]

Voltage symmetry, operational description?

Is the original TGS designed to have postive voltage at +8V and negative at -5V? I mean, would it harm if the negative voltage is increased (close to -8V) by slightly modifying the output circuitry of the 4024? Anybody tried that?

I have read all 125 pages of TSG messages, but couldn't find operational description for the TSG. While the main princible of operation is quite clear, I still can't figure out how the ground balancing, discrimination and notch circuitry work in detail. I guess they'll become self evident, when I build this device. I just have a bad habit of needing to understand what I'm doing.

All hints appreciated,

[perdica 2]

i think this schematic is without any mustakes
need confirm from Molzar (for those cap`s in picofarads)

[simonbaker]

wrong schematic drawning R-3k3 from TX at disc-notch pot , at PSB picture 3k9

It's good to point out all these little differences, whether important or not. We should try to get an exact schematic of the real TGS. According to Molzar there is another 220 uF capacitor after the LM7808 not shown on the schematic also, as well as original parts. Let's get it right for the record. I wish we could help Molzar, but he has it to himself. Can do some work with the photos however.

Cheers,

-SB

[perdica 2]

wrong schematic drawning R-3k3 from TX at disc-notch pot , at PSB picture 3k9

[simonbaker]

Here is schematic and component from early posts."W. Lahr" is not on this schematic, but I've looked at so many of these Tesoro schematics I think this is his work.
On component lay out only values I can see different are TL062 is LF442 and BF245 is TIS75 (like in schematic). Only one can not tell (yet) is Zener diode in Tx circuit. All the other values seem to be correct. The missing diode (4140) is on the bottom LM308 (on the schematic) I believe, the gnd bal circuit.

Will do more pains taking analysis of components, but no time right now, but Kurtie100 component layout and PCB from post #1 seem very accurate.

Also have to double check frequency for 8" coil as I think antenuation settings for counter may not have been correct.

Molzar

Thank you very much!

Regards

-SB

[perdica 2]

if you can check caps in pikofarads and told their value

thanks for pictures

[Molzar]

Here is schematic and component from early posts."W. Lahr" is not on this schematic, but I've looked at so many of these Tesoro schematics I think this is his work.
On component lay out only values I can see different are TL062 is LF442 and BF245 is TIS75 (like in schematic). Only one can not tell (yet) is Zener diode in Tx circuit. All the other values seem to be correct. The missing diode (4140) is on the bottom LM308 (on the schematic) I believe, the gnd bal circuit.

Will do more pains taking analysis of components, but no time right now, but Kurtie100 component layout and PCB from post #1 seem very accurate.

Also have to double check frequency for 8" coil as I think antenuation settings for counter may not have been correct.

Molzar

[simonbaker]

Hi,

Simon I think W. Lahr schematic is pretty accurate. Changes already noted (2-47Ks <4.7K>, 150pF<15pF>, and 100K resistor from LM 393 pin5 trace error) I only see two other differences:

1) 220uF cap on 8v line (right after regulator) So there is one before and after regulator!

2)The 1n4140 is missing on the one of the LM308s. This is interesting because it is on the (Lahr) schematic but is not on original PCB. So everyone thought this was just mistake on Kurtie100 pcb. This unit was produced after spring of 1986. Golden Sabre first came out in 1985. This is Rev C PCB, so if this was mistake they had plenty of time to fix it. I think also maybe makes no difference at all in performance.

Like I said before Kurtie100 component drawing (and PCB) is very accurate!

Parts are as per component drawing TIS75, 2222A, MPS13, LF442, etc.

Audio circuit (after LM35 is as per Schematic, 16 ohm speaker is LOUD!

Put Freq counter on Tx output tonite.....13.985 kHz with original 8" coil. Will try also with Tesoro 10.5 concentric coil I have but need to do some soldering to connect it.

One time I will do pains taking schematic check, maybe during long winter.

Next I will try 10.5 coil and DD coils, maybe few days.

Molzar

1) 220uF cap on 8v line (right after regulator) So there is one before and after regulator!
I searched thread for "lahr" but only found this message. I would like to identify exactly which schematic you mean (because there are several in this thread). Can you tell us which message of this thread it is attached to?

Ah!

Which LM308 is missing the diode? Does anyone have an idea why?

Some parts are not identifiable from your photos. Are they exactly as on the "Kurtie component drawing"?

Thank you for your excellent work, all your comments are of interest!

Regards,

-SB

Hi,

Simon I think W. Lahr schematic is pretty accurate. Changes already noted (2-47Ks <4.7K>, 150pF<15pF>, and 100K resistor from LM 393 pin5 trace error) I only see two other differences:

1) 220uF cap on 8v line (right after regulator) So there is one before and after regulator!

2)The 1n4140 is missing on the one of the LM308s. This is interesting because it is on the (Lahr) schematic but is not on original PCB. So everyone thought this was just mistake on Kurtie100 pcb. This unit was produced after spring of 1986. Golden Sabre first came out in 1985. This is Rev C PCB, so if this was mistake they had plenty of time to fix it. I think also maybe makes no difference at all in performance.

Like I said before Kurtie100 component drawing (and PCB) is very accurate!

Parts are as per component drawing TIS75, 2222A, MPS13, LF442, etc.

Audio circuit (after LM35 is as per Schematic, 16 ohm speaker is LOUD!

Put Freq counter on Tx output tonite.....13.985 kHz with original 8" coil. Will try also with Tesoro 10.5 concentric coil I have but need to do some soldering to connect it.

One time I will do pains taking schematic check, maybe during long winter.

Next I will try 10.5 coil and DD coils, maybe few days.

Molzar

[Fred]

Hi Molzar,

Thanks for the great pictures.
Interesting!
Regards,
Fred

[simonbaker]

Hi,

Did some air tests with 8" coil.


Discrimination Mode (Full Sense)

US 25 cent = 20 cm (Silver)
US 5 Cent = 22cm

All Metal Mode may be 1-2 more cm

Unit becomes a little unstable set at 9 or above on Sense.

So no surprizes.

Took apart tonight to have closer look inside. Component values and locations seem to be as per Kurtie100 component layout. Haven't checked every component as yet but did check quite a few and they match perfectly. Solder side of pcb is work of art. Artwork was made by hand (like they did in the 80s) and is very curvy. ICs are Motorola and NatSemi. Sorry I can't post photo but no good camera here. Will post some shots next week. Might be tough to get good shot of component side because of all wiring.

Also things are not going well here personnally so hobby may take "back chair". But I try to post next week.

Molzar

Those air tests are pretty close to air tests I get with my Tesoro Compadre with 5.75" coil. Interesting. People on this forum have really extended the power of TGS with coils and maybe small changes! I think very exciting to try to get perfect schematic of this actual TGS.

Biggest curiosity is audio circuit because of problems talked about here. However, maybe it's largely because of extra sensitivity achieved, pushing the limits????

Regards,

-SB

[erolunall]

Dear Molzar

Thank You for good photos
if you sent info about parts (transistors and others) is same or not with shema will be helpfull for all.
İf you could sent this photo before this thread will be not soo much long


Best Regards
Erol Ünal