The Stovebolt Site Forums The Shop Area The Electrical Bay The Radio Bench Smoke Coming From Radio

I've got a '53 3100 that's been converted to 12 volts. I still have the original radio and I've had it reconditioned. It works pretty well. Probably as good as it did when new.

I put a big resistor on the power wire for the radio to cut the voltage down to 6V. But when I'd play the radio I get smoke coming out of it.

I finally figured out that the radio was still getting 12V through the light bulb circuit. I had just changed the bulb from a 6V bulb to a 12V bulb and hooked the light bulb wire up to the light switch. It took a bit of troubleshooting to realize that when the radio and lights were on, the radio drew power from both wires.

To resolve the problem, I replaced the 12V bulb with a 6V bulb (actually 7.5V), removed the light bulb wire from the radio and now I run both the radio and light through the resistor.

This seems to have helped. It used to start smoking right away, now I can run the radio for about 20 minutes before wisps of smoke start coming from it.

I’ve checked the voltages and everything seems to be right. Any idea what might be wrong and what to do to correct the problem?

You might as well take the back off and see where the smoke is comming from. Sometimes a resistor will be damaged enough to carry on like that for a while. However, it seems a little unusual.

Thanks for the reply.

I've tried that. Of course when I have the back off there's no smoke. Nothing inside appears charred or damaged.

I would run it on the bench until it stops smoking. Come to think of it, did you say you were using a reducing resistor? Maybe the resistor has a problem.

Did they replace the buffer?

I'm not sure. What's the "buffer"? What's it look like and where's it located?

If I know what I'm looking for, I'll try to find it and see if there's any signs that it might be the cuplrit.

Thanks!

On the bottom side of the chassis underneath the vibrator socket, there is a metal plate. If you remove the plate you can see the buffer capacitor. It is also on the diagram, outside the transformer case as depicted.

I've seen power transformers that have been beaten by a bad buffer ,and even after the buffer has been replaced the transformer will still heat up and smoke!
Lets first see if your running on the 6 volt measure the voltage between your resistor and the radio with the radio playing .
The dial light should be completely seprate from the radio and have no efect.