The Stovebolt Site Forums The Shop Area The Electrical Bay The Radio Bench Radio Bench Testing

This may be a stupid question, but it’s not the first one I’ve ever asked and probably won’t be the last . . .

I’ve got a problem with a radio from 1953. The radio has a voltage reducer so it can run on 12V (like the rest of the truck) and recently just stopped working — no sound (not even static) and no light.

I’ve also got a battery charger with a 12V, 100 amp starting feature. My question is: can I use the battery charger to bench-test the radio?

My primary goal is to not start a fire. The secondary goal is to not create a bigger problem than I already have.

My plan is to simply look for a loose or broken connection so I don’t want to spend a lot of money buying a power supply. Anything more difficult than that I’m probably going to have to take in for repair.

Well yeah, you can do that but with caution. I would put a small amp fuse between the charger and radio. I would size the fuse to the same amperage as the radio has in the truck. If you short something out trouble shooting, you blow the fuse not the radio.

You don't want to run the radio on 12 volts. A 1 ohm 50 watt resistor in line with the charger will drop the voltage properly. Of course you would also need a fuse. If you have the original mechanical type vibrator and it is not buzzing, the radio will never work until it is replaced. They sell solid state versions now.

He says he has a voltage reducer but not which kind. If I were him I would first probe the output of the reducer (what ever kind) with a voltmeter to see if it is the problem.
Truckernix is right, no vibrator, we 'fuse blowers' call them choppers, it will not work. If you heard 'motor boating' before it went then the big electrolytic capacitors in your power supply is most likely your problem.

Thanks for the idea of bench testing a radio using a battery charger and of course the appropriate fuses....would have never thought of using a battery charger.