Transistor Radio Troubleshooting with Signal Tracer

[@cliffjones7868]

You forgot to turn the Radio? Murphy must have your attention😁. Been there, Done that!

[@brendanryan6363]

Thanks for the video, very easy to follow. Can you tell me why the signal is audible just by touching the tops of the capacitors etc? Is the audio signal just flowing around through all components, on the positive and negative sides of the components or just the negative? Thanks for any advice

[@timtimeprojects3576]

Brendan, Great question. without looking at the schematic or tearing it apart, my guess is that the capacitor " -" lead is not tied to a ground, or at least not the same ground that the Audio is. So, when I put the probe on it, it would be just like putting the probe on either lead of a resistor for or coupling capacitor for example (provided that lead is not tied to ground of course). In general, I don't normally expect to hear signals when I touch the case of many components. That is a good reminder to be careful of what your test leads or power supply leads touch.

[@brucebuckeye]

Great video, thanks for posting. Are not some of the older transistor radios positive ground?

[@shriraamsugavanam1870]

Dear sir I am having a radio cassette tape recorder. The cassette and AUX In works fine, but the radio is not picking up any stations since last week. It doesn't have FM band because it is an earlier one. When I touch the MW internal antenna coil I can hear a station with only mild volume. But when I touch the telescopic Ariel for SW 1 &2 i can't hear anything. When I don't touch the MW coil I can't hear the station. Kindly tell me what to do next. Thankyou sir.

[@cajuncoinhunter]

If you can find a schematic online for your unit , look into it and find your AM radio input side , then follow to your first transistor , check the input signal the the output signal of it..... then go to the next one ETC ETC ...

[@tijitwar7071]

Hi. Is it possible to get the circuit diagram of the signal tracer, please?

[@timtimeprojects3576]

That is just the Velleman 7000 kit . It is available all over the internet.

[@rayislooking2]

Hi Have you tried an oscilloscope probe? Just1

[@timtimeprojects3576]

The things I used were like 1:1 probes but I didn't want to introduce the scope probe 10:1 components into the circuits.

[@rayislooking2]

@@timtimeprojects3576 I understand that makes good sense . I wonder if 1:1 introduce components too? Probably not a good idea. When you can make one so easy. Thanks for sharing. Just1

[@hansepie]

Thank you so much for sharing your knowledge with the rest of the world. I really like your work. Somewhere you mentioned the spill over noise of about 1000 Hz. That made you decide to split the input and the output. I happened to view another vid about this Velleman kit where the same interference happened. It was treated by connecting the housing of one of the potentiometers to ground. Look here from 16:30 for the solution. kzbin.info/www/bejne/ooG1gINmmtN3mck

[@timtimeprojects3576]

I actually did that as well. Thanks for the information.

[@marcomeleagri5519]

Che marca e modello e questo generatore di segnale ? Grazie....

[@rduwe9466]

what are you actualy doing?? just poking around you call that atroubleshooting?