TESORO GOLDEN SABRE

[Ruben2000]

I don't know why the photos are coming out inverted.

[Ruben2000]

hello banner!
I also opened my non-discriminating TGSL and took the measurement at the -5V point and got -6.5V.

[dbanner]

[dbanner]

i am now curious to measure the negatve voltage rail on my home brew tgsl. just for comparison.

I just measured the negative voltage supply(rail) on my tgsl. It sits at -6.14V. This is more in line with what the schematic of the voltage inverter should derive.

That is with the whole circuit connected and operational.

The -5V on the schematic is wishy washy

[dbanner]

i am now curious to measure the negatve voltage rail on my home brew tgsl. just for comparison.

[Ruben2000]

hello banner!!
I changed both the capacitors and the diodes for new ones from the store and there were no big changes; I took the measurement and got -7.31v.
I will continue with the next steps. I'll go to block number 4 which is the RX stage and see what happens.

[Ruben2000]

Thank you for your appreciation banner, I will change for other elements and see what happens.

[dbanner]

Maybe it is bad 220uF cap to ground. On the negative rail you should not see any ac waveform.

[dbanner]

The diodes that I placed have the denomination ST4148.

could it be Zener diode?

No, I dont think so. It is ordinary diode same as 1N4148?

[Ruben2000]

Hmm, I you salvage diodes from those boards you got, then watch out for schottky type.

Those have low junction forward voltage drop as is well known. Maybe account for the -7.4V you measured.

The diodes that I placed have the denomination ST4148.

[Ruben2000]

What circuit you made your inductance meter?

I got it out of here.

https://youtu.be/hMa-AWyuxaA

[dbanner]

Hmm, I you salvage diodes from those boards you got, then watch out for schottky type.

Those have low junction forward voltage drop as is well known. Maybe account for the -7.4V you measured.

[dbanner]

What circuit you made your inductance meter?

[dbanner]

I am not so good at these things. But the document says negative 5volts, which I can't see how. Perhaps when connected to the rest it is closer to 6 volts.

I just say the negative rail and leave it at that.

[dbanner]

Although -7.4V maybe should be closer to negative 6.8V.

Silicon diode have voltage drop of 0.5 to 0.6 volts across junction. So I should expect to see -6.8 or thereabouts.???