Electrical: 6 volt radio in a 12 volt system

[brngarage]

This question has probably been asked before, but I can't find a thread about it. Can I use a 6 volt radio in a car converted to 12 volts, with a resistor or a Runtz or does the radio need to be "converted" to 12 volts? Thanks.

[Lynn]

My 49 2R16A has been converted to Chevy power with HEI, so I had to use 12 volts. However, my gas gauge and my horn are both run on 6 volts. I purchased a cheap six volt converter, and run those two accessories through it. No reason you can't do the same with your radio. The type of converter I used is set out in my build thread. I would just tell you, if I could remember off the top of my head. Just search for threads started by me, and look back to sometime in 2016, I believe when I decided to commit sacrilege and go with Chevy V8 power.

[r1lark]

Howard, is it a positive ground 6v radio? And was the car converted to negative ground when it was converted to 12v? This may very well make a difference if the radio is polarity sensitive.

There are a couple people on the forum who work on old radios, they should chime in here soon.

[brngarage]

Paul, it is the original Studebaker 6 volt radio, so it is from a positive ground system.

[Jeff_H]

If its the radio for the '53, those take about 4-5A if the non-pushbutton one and more like 8A if with pushbuttons.

In the past folks would use a big power resistor to drop 6V for those. That will be around 50W of power. Not a real good solution.

The solid state replacement vibrator cans are polarity sensitive so you would need to verify what is in there. The mechanical points vibrators are not.

Runtz regulators for gauges are only for low current and way too small for the radio.

You CAN convert it to 12v. Requires replacing all the tubes and changing the vibrator transformer.

There maybe folks selling switching power supplies for this sort of thing, but those often have various problems as many are poorly designed and noisy (noise on the AM radio).

Many have their radio "gutted" out and workings replaced with modern AM-FM modules designed for this purpose. I think the newer ones have inputs for mp3's etc too. There are folks that do this service.

In any rate, a original radio will need all the old wax paper capacitors replaced. If not already bad, they will not last long if put back in use.

[gordr]

The original tube radios were not polarity-sensitive, unless, as Jeff remarked, somebody installed a replacement solid-state vibrator. A dropping resistor is not a real good solution, as the current demands of the radio vary between initial turn-on and continued operation. The conversion of the original radio to AM/FM/mp3 is looking increasingly better, if for no other reason than there is little worth listening to on the AM band anymore.

[RadioRoy]

There is an inexpensive ~$30 or less, dropping device made in China that can handle the power. The problem is that it puts out exactly 6 volts. But a 6 volt radio really needs around 6.3 to 6.8 volts. What were they thinking?

[altair]

Get yourself a 6 volt motorcycle battery and run the radio off that and leave the 12 volts alone. Get a battery maintainer and plug it in at regular intervals to keep the 6 volt battery up.