TGSL Tuning & troubleshooting

[homefire]

See if this helps.

[BKY1337]

Thanks, but i think this is not my silverdog version of the TGSL EDU.

[homefire]

Yes it's the same. I have the board right here in front of me. I'm working one here my self. Working on a coil even as I type. LOL

[ripsdevala]

Homefire, that part of the coil is not shielded?

[BKY1337]

i cant find the two transistors at the right side, it looks different for me sorry.

And i dont know which voltages i need to have. Are they the same as in the schematic?

[homefire]

Dang Dude you making me work here. Anything not connected to ground is not shielded on coil .

Ok, How about this one ? I pointed to ground side of Tx. Test Point one is the Tx on GND Side. Source is next point to right.

[BKY1337]

Thank You!

Are the voltages the ones from blobber testpoints?

[ripsdevala]

Dang Dude you making me work here. Anything not connected to ground is not shielded on coil .

Rx don't need shielding???

[BKY1337]

I got:

1: -10,27V
2: 184,4mV
3: 138,3mV
4: 113,4mV
5: 3mV
7: about 20mV and changing

Pin 6 of 4024 is 1,375V

All measured in DC with negative Probe at battery minus.

[BKY1337]

How much Volts needs the Colpitts Oscillator at the input (24k Resistor).
I have only 0,758V there and nothing is oscillating.

I think the problem is here and i can trace it until i gonna find the error without disassembling the whole board.

And how can somebody get about 16 Volts at the TX testpoint? Is this the battery Voltage with a stronger battery?

[homefire]

If you look at the TX Oscillator arrangement the Two Capacitors work as a Voltage Doubler.

[homefire]

Check for Oscillation on collector of 2n2222. Your meter may be loading it enough to prevent it from Oscillating.

[BKY1337]

i have measured between collector and tx1, tx2, rx1,tx2 and got nothing.

[Hyena]

Hard to troubleshoot without oscilloscope, isnt it?

[Hyena]

i have measured between collector and tx1, tx2, rx1,tx2 and got nothing.

Measure Tx voltage. Make sure, you are in AC 20V range! Black to GND, Red to Tx, you should get 13-16Vpp.