TGSL Tuning & troubleshooting

[Hyena]

homefire. I have already measured this and posted.

0,7V at the upper power connection. (above 24k Resistor in the schematic)
And 0,5V at the base of the transistor.

I think i need to buy a new LM7808 and maybe change the 220 electrolytic capacitor.

No spare 7808 , i have ordered 6pcs right now. I need to wait until they have arrived.

7808... If you measure DC voltage between ground and pin 8 on LM358, LM393 or LM308, do you get 8V?

[BKY1337]

homefire. I have already measured this and posted.

0,7V at the upper power connection. (above 24k Resistor in the schematic)
And 0,5V at the base of the transistor.

I think i need to buy a new LM7808 and maybe change the 220 electrolytic capacitor.

No spare 7808 , i have ordered 6pcs right now. I need to wait until they have arrived.

[homefire]

Hope you have a spare.

[BKY1337]

I got only 0.7V at the output of the 7808. I think this is the problem.

[homefire]

Guess you need too check and see if you have power.

[BKY1337]

I didn't saw that i need 8V. This was what i wanted to know.



So i think the problem is the power supply.

Edit: I have 0,5V where it needs to be 5.29V.

[homefire]

Dang Dude, Buy the $20.00 scope and be happey for what it will do for you.

Do you know Ohms Law ?

[BKY1337]

I have built my coils this way. Im sure that nothing oscillates. My Multimeter can handle up to 200kHz.

I hope that the only problem is that nothing oscillates and everything else is still fine.

I have measured both directly at the tx and rx connector pins.

I can remember that my TGSL began to clacker and the clackering became quieter and quieter until it was damaged.
Sounded like a loose connection. Sometimes it worked again after the clackering.

I cannot find the testpoints from the TGSL PDF at my Board because im too stupid for it.

[Hyena]

Thanks, but i dont know how to use it and i think i dont need it to find the damaged part.

I cannot test the voltages because i dont know how they need to be. My Coils are not oscillating. Coil was connected.
then i think i need to check the colpitts oscillator but i dont know how much voltage it needs.

Its difficult for me to understand the schematic.

Maybe its easier to buy new ICs and check if it runs with new ones. If not, desolder the transistors and check them, then diodes, and then change the resistors with new ones.

Sorry man, but you are wrong. You definitely need it. How you know that your Colpils is not oscilating when you have no oscilloscope? One of my DDMs is able to measure 16V AC on TX. But Its not able todetect <1V after 1st op amp on Rx stage. Are you sure, your DMM is able to handle 15kHz? How? Do you set it up properly?


Without scope you are not able to see GEB and DISC channels. You can only guess... And rest of circuit is the same story.


How much voltage it needs... is all written in PDF about tgsl - again for oscilloscope. You will save hours, maybe days of your time (and ours of course ) if you buy one. Because we can only guess you use DDM right and connect it properly to circuit.

[BKY1337]

Thanks, but i dont know how to use it and i think i dont need it to find the damaged part.

I cannot test the voltages because i dont know how they need to be. My Coils are not oscillating. Coil was connected.
then i think i need to check the colpitts oscillator but i dont know how much voltage it needs.

Its difficult for me to understand the schematic.

Maybe its easier to buy new ICs and check if it runs with new ones. If not, desolder the transistors and check them, then diodes, and then change the resistors with new ones.

[homefire]

These sure are better then NOTHING ! https://www.banggood.com/it/Orignal-...r_warehouse=CN

[homefire]

You cave in too easy. You do have your Tx Coil in circuit , Eaa?

[BKY1337]

I think an Oscilloscope wont help me because nothing oscillates.
I have 3mV in both AC and DC between GRND and TX.
Between RX and GRND its about 178mV.

Damn, it was -10,78V before at TX

I fear that i need to make a whole new board becaue im a electronics newbie.
I want a smaller one anyways.

[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.

[Hyena]

Hard to troubleshoot without oscilloscope, isnt it?