AM car radio to 120V?

[Guest abh3usn]

Is it worth converting a 12V AM radio to 120V to use as a shop radio? Or is this more screwing around than necessary? I'm looking at a '58 Studebaker radio and thought it would be a neat idea.

[Guest simplyconnected]

It IS a neat idea, but it's not worth it. All your tubes have 12-volt heaters, and you would have to find another transformer with a 120v primary instead of 12v.

What you can do is keep the radio as it is, and hook it to a 'spare' car battery. (I always seem to have one around the garage.) And, keep it on a trickle charger (I have one of those too). The battery will run the radio at least ten hours/day. You can put the radio, speaker, and antenna anywhere you want. Fuse it to protect the feed wire. If you use lamp cord, fuse it for 8-amps on one leg at the battery. It's a good idea to keep the battery in a plastic battery box (available at the auto parts stores).

I've often thought about using a car battery to run my computer. It's the same as an uninterruptable power supply. All I need to do is keep a charger on a battery, located in the basement just below my computer room. At 600-watts, a car battery will run this computer for at least a half hour or more, lending plenty of time to start my portable generator.

[Steve Braverman]

You can go to Radio Shack and get a 120VAC to 6VDC transformer. When I was a kid, my friend's dad worked for Clarion, and he had a similar setup in his bedroom.

[Matt Harwood]

Would something like a landscape lighting transformer work? I have one that converts 120V to 12V and puts out 600 watts. That ought to power a radio, yes? They're at Home Depot for like $30 for a small one (say, 60 watts, which should be enough). That is, if it'll work. I have no idea.

[ply33]

You will need 12v DC to run an old car radio. But that is no problem: A lot of ham radio gear is 12v DC because they want to run it on batteries during power failures (i.e. disasters). So go to your nearest friendly ham radio store and get a 13.8v DC power supply that plugs into the wall. Wire your Studebaker radio into that and you are all set.

[Guest simplyconnected]

The best way to determine watts, is to look at the fuse for the radio. If it says 5-amps, 12v X 5a = 60-watts. So, you would need a regulated rectifier (changes AC to steady-DC) that handles 60-watts. To be safe, you want to double this value because of heat. Where do you get one? Old computers have regulated power supplies that put out +12v@5a. You could probably get one cheap, too. Note, they are fan-cooled and need air flow.

A word of caution, "wall-warts" aren't filtered, meaning they put out pulsating DC. Your radio will deliver 60-cycles straight to the speakers, and your radio's vibrator will go nuts because input power isn't regulated.<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Matt Harwood</div><div class="ubbcode-body">Would something like a landscape lighting transformer work?</div></div> Good idea Matt, but it puts out 12-volts AC. Even if you rectified the output, it would still be pulsating DC. The power supply needs to be REGULATED (steady/constant) +12VDC.

Battery chargers aren't regulated, either. But once you connect them to a car battery, the battery smooths the voltage right out, all by itself (like a big capacitor).

<span style="font-family: 'Arial Black'">So, either an old computer power supply that outputs ~5amps of 12volts, or a spare car battery with a small (1-2amp) charger. I like the idea of a ham radio power supply, but how much are they and where can you get one?</span>

[Jim Bollman]

My Dad use to make these conversions for friends. I have one on the shelf in the shop. It hasn't been fired up for years, probably doesn't work anymore. The conversion made sense in the 50s to get a rugged shop radio. Today how many of us want to listen to AM radio in the shop.

I picked up an old stereo tuner/amp at a garage sale for near nothing. Put it on a high shelf with a couple of speaker on the walls. I'm on my third one over the last 30 years but when they are free or close to it you just pitch them when they fail.

[Guest simplyconnected]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jim Bollman</div><div class="ubbcode-body">Today how many of us want to listen to AM radio in the shop.</div></div> True, but I still like seeing an old Coke machine, or juke box. It really is novel. Modern stereos are so much better, and cheaper, and hugely more efficient. Some guys gut the insides of old radios and put modern tuners inside, but not me.

My original AM Motorola radio in my '55 works just fine, and is VERY novel to hear and "run." The only part I changed is the speaker.

abh3usn, you go ahead and use your Studebaker radio. It's very rare, (and cool) to have anything from back then that survived father time.

[Durant Mike]

Are there even any decent AM radio stations left that play music?