TESORO GOLDEN SABRE

TGS

For MAX
Ref: TGS (28DD coil)




I report you which the coil wound whith 26ohm TX and 27.5 ohm RX.
I bought a new NICAD battery and change the capacitor 100pf by 220pf (near LM 353)….now it is functional, but very, very very
sensible. When it is stopped on the table no audio signals, but a finger soft touch on table, cable, box, pole or coil produce a short
sequence of BIPS. Is it normal ?

What the best solution for it?
Regards


DIRCEU

[Max]

Max, ivconic,

Thank you to the help and the information.
Now, I have other question:
What is the right value for C7 capacitor? and what is its role?
Please, excuse me, if you are already discussed it.

Hi,
well... we need a picture of an original TGS to say that. In some other schematics it's 5pF there. So maybe that's right value. I've mantained it at 10pf cause noticed that detectors works cool with that value.

I think that original was 5pF... but change a few if you have 10pF there.

So it's your choice using one value or another.

Kind regards,
Max

[rdec4]

Max, ivconic,

Thank you to the help and the information.
Now, I have other question:
What is the right value for C7 capacitor? and what is its role?
Please, excuse me, if you are already discussed it.

[Max]

Hello Friends

There are one diference with schema and Pcb of TGS. There are 1 more 1n4148 diyot on schema near lm308 paralel with 1M and 22n but not shown PCB parts replacement.it is important or not ?
Regards
Erol Ünal

Hi Erol,
thanks for that information: I've missed that diode at all !

Now it's about clear that first PCB hasn't it as I've indicated in picture: the upper LM308 hasn't any diode there, instead the lower has it as in schematics (where is the arrow).

I think this fact could explain why there are sometimes noticeable differences between TGS and TGSL.

The function of diode there is limiting dinamic range of op amp. This fact could be strongly related to instability in TGSL... but I think topic need some more investigations.

Anyway, it's absence seems is not a problem on TGS: I haven't it on board just like PCB picture and everything works cool.

Best regards,
Max

[erolunall]

Hello Friends

There are one diference with schema and Pcb of TGS. There are 1 more 1n4148 diyot on schema near lm308 paralel with 1M and 22n but not shown PCB parts replacement.it is important or not ?
Regards
Erol Ünal

[Max]

Rdec4 yes make conntact to gnd but in coil, not at pcb. This is already explained earlier.

"..Often also battery holders are cause of problems: movements make contacts expose different resistance and thus giving erratic supply voltage with movements.."

Yes it is true! After a lot of troubles with various holders in the past ...finally i decided to solder batts. Eversince than i have no simillar problems.
But sometimes is pretty tricky when soldering batt. pins...

Hi,
I've done too a couple of times: used zinc chloride.
First I scratch surface with little piece of fine emery paper , then put over contact some small quantity (maybe 10mg) of zinc chloride paste that's kind of old flux stuff for big solderings works like soldering metallic parts... then use a 60-100W soldering iron to heat up that thing and add some small quantity of solder-alloy (lead-tin one).

You can do similar even without zinc chloride... but just scraping surface: the rosin cored wire will polish metal enough to make good solder joint.

Only care will be put on timing the soldering operation: I do everything in max 3-4 seconds to avoid damaging cells by heat.

Best regards,
Max

[ivconic]

Rdec4 yes make conntact to gnd but in coil, not at pcb. This is already explained earlier.

"..Often also battery holders are cause of problems: movements make contacts expose different resistance and thus giving erratic supply voltage with movements.."

Yes it is true! After a lot of troubles with various holders in the past ...finally i decided to solder batts. Eversince than i have no simillar problems.
But sometimes is pretty tricky when soldering batt. pins...

[Max]

".....between 12.4V and 7.47V...."

What are you saying here????

No matter if charged or fully discharged, 12v battery must show always 12 Volts!
If 12v battery showing less than nominal voltage that it is damaged and unuseable totally! Even if it is showing 11 volts - it is damaged...toss it through some window and put brand new one...
For example; my 12v/1.2Ah when fully charged is showing 13.8v...when fully discharged is showing 12.8 volts...obviously it is in good shape and useable.

Check your battery again. Check it disconnected from device and later check it connected to device. First device switched OFF than switch it ON during measuring...Than you can see eventual voltage drop. If it is droping bellow nominal voltage.....it is damaged....conclusion; toss it!
Regards!

Hi,
I think he mean something like NiCd battery pack: when batteries are really low on charge they can reduce voltage at leads to a fraction of volt. But if that happens I think he need charge better them or change for new batteries (sometimes damaged batteries last a few after charge).

If my idea is right he gets lot of voltage after charge withoud any load, so he thinks batteries are fully charged, then connecting to circuit the voltage accross drops too fast from top voltage and then that variation is detected as erratic bleeping at detector.

Often also battery holders are cause of problems: movements make contacts expose different resistance and thus giving erratic supply voltage with movements.

Kind regards,
Max

[Max]

Has or not contact to the negative battery pole clamp in RX coil?
According the schematics, in TGS Light - Not?, but in TGS - Yes?
What is true?
I readed contradictory opinions

Hi,
yes one lead of RX is connected to gnd: in standard tesoro's coils that happens inside the coil housing, then the wire from tx side at gnd potential is connected to shield and lead of rx inside housing. No matter of e.g. pcb tracks at rx about that: coils are this way.

So, you have to made it as in original coil.

Then some users reported also that detector works cool (or even better) without connecting RX lead to gnd: it's your choice doing thatway, but remember you need shield connected to gnd in any case to avoid capacitive problems, otherwise coil will be totally useless on soil.

Best regards,
Max

[rdec4]

Has or not contact to the negative battery pole clamp in RX coil?
According the schematics, in TGS Light - Not?, but in TGS - Yes?
What is true?
I readed contradictory opinions

[ivconic]

".....between 12.4V and 7.47V...."

What are you saying here????

No matter if charged or fully discharged, 12v battery must show always 12 Volts!
If 12v battery showing less than nominal voltage that it is damaged and unuseable totally! Even if it is showing 11 volts - it is damaged...toss it through some window and put brand new one...
For example; my 12v/1.2Ah when fully charged is showing 13.8v...when fully discharged is showing 12.8 volts...obviously it is in good shape and useable.

Check your battery again. Check it disconnected from device and later check it connected to device. First device switched OFF than switch it ON during measuring...Than you can see eventual voltage drop. If it is droping bellow nominal voltage.....it is damaged....conclusion; toss it!
Regards!

[ivconic]

"...I think your problem is not related to voltage but something else...? "

Just look what i posted????

Yes i think your problem is related to voltage there! But you confused its behavior.....Check all over again. It must work with 14V perfect...

[ivconic]

Thanks IVCONIC and MAX


Finally my problen is solved. My battery pack give me 14.8 V instead 12V.
When the battery discharge... between 12.4V and 7.47V , all work perfectly.
I have a mechanical problems too.

Sorry my english and my stupidity. I am a begginer.

Regards,

DIRCEU
Brazil SA.

To tell you the truth; i do not understand this!?

My battery is labeled as 12v/1.3Ah but always showing 13.7v...and device is working perfect.
In my latest 3 TGSL handmades i put 4x3.6v (Nokia) batteries, which gave 14.4 when calculating, but in practice always giving 15.xx volts...and those are working perfect also...
I think your problem is not related to voltage but something else...? But what?
Did you put 7808 regulator there? Is it in good shape? Check those 220uF capacitors. Are they leaking a bit?
Check that all again...something is "misty" there....

[Geo]

Luck for you is that your wife is not member of this forum...also!

And she don't speak English

[ivconic]

Yes but my wife was to Greece

Luck for you is that your wife is not member of this forum...also!