So I know there are a whole slew of threads on here about converting a 6v positive ground to a 12v negative ground and they all say the same thing over and over again but not a single one seems to address if I can use my old radio or not. I've got a 53 Merc Monterey that has a beautiful radio that works (kinda) great and I don't want to have to dump it for some new fangled POS. Anyone out there know the workings of these well enough to tell me if the polarity change will fry it or if I can just use normal voltage reducers? Thanks in advance Jack
Convert to 12V and then have your pretty radio converted to work on 12Vs and get some great AM/FM sounds in the process. It costs more than an ugly replacement but it's worth it IMHO
OK so just what do you listen to on AM. You're into talk radio? Buy yourself some ugly POS AM/FM radio and slide it under the seat. Problem solved.
i was just chasing this same idea a few days ago. Read this. it can be saved but not cheaply. Sorry.... http://www.antiqueradios.com/forums/viewtopic.php?t=118412&highlight= so what driving you desire to change to 12v?
by the way i have wired my 6v tube radio to recive a ipod and it works great so ignore all those naysayers about nothing on a/m
This gentleman is a H.A.M.B.'er and may be able to offer some insight on your stock radio, or if need be converting it. http://www.joesclassiccarradio.com/
Your Ipod pics up AM. I got an IPOD and all it'll play is MP3s. So if I wire my IPOD to run through an AM radio I can get improved AM programming? I'm just trying to understand the logic here.
The old radio is AM-only. He added an Ipod hookup so he can play his MP3s through the old radio. Radio is still AM-only. Ipod is still MP3. He just helped them get along.
There are many ways of doing this, I have used a 6v sealed rechargeable battery and just separated the radio from the car power. Also, you need to isolate the radio chassis from the radio enclosure using rubber grommets. There are voltage regulators like the LM317 (Schematics are available on the net) that are variable from 1.2v-37v, with the addition of a transistor to increase current. Again, remember that the ground is now negative instead of positive, the chassis of the radio has to be isolated from the surrounding frame.
I think he assumes that tube radios care about the polarity of the power source. Generally they don't, because the filaments are the only things that run on low voltage DC, and they're basically light bulbs. The high voltage is generated by a vibrator, step up transformer, and rectifier tube, so it doesn't matter what comes in, it will make B+ Like you said earlier if it has an electrolytic filter cap on the input power, that would need to be removed.
It seems to me that it would depend on how he is charging the 6V battery. Depending on how he's accomplishing that, connecting the case to the positive terminal of the 6V battery (pos. ground) and to the negative terminal of the 12V battery (chassis ground) could create a short. On the other hand, if they're floating in reference to each other or if he doesn't charge the battery from the 12V system it wouldn't matter (might also be able to get this to work with some sort of battery isolator?). (edit - I'm assuming 440roadrunners comment I quoted follows from the comment about adding a second battery to the car)
Squirrel and 440roadrunner are correct. The only things that must be checked are any polarity sensitive components between the battery and vibrator, including the vibrator. Finding a 12V vibrator will be fun, look at car radios from 53 to 58. Most 59 radios were built to use low voltage and a power transistor for audio output, without the use of the vibrator and step up transformer. PM me about 12V conversion.
There is a great rockabilly and old blues station up here called KIXI it's 880 AM and plays old radio dramas and everything else. It's pretty amazing.
Another alternate solution. Run a separate 6 volt battery in the trunk for the radio. Charge it occasionally.
There is no reason to convert to 12 volt if I want to keep my old radio? Really? I'm looking at better starts, better charging, brighter bulbs etc. I wasn't aware fancy new radios were the only reason people converted. There is a guy out on the web ( www.rediscoverradio.com) that sells something I'm VERY interested in. It basically allows you to use your radio like headphones by giving you a plug to connect to your Ipod or Cd player. And really what is wrong with wanting to keep my radio?
How much work do you want to do? If you want to learn how it works and do the work, you can make it run on 12 volts and hook up your ipod. It is not a simple task but can be really rewarding. Similar tube filaments can be rewired in series or regulated with a voltage regulator, which is the easy part. If it was me, I would make my own B+ supply to get some better regulation and filter the filament supply. The old capacitors are likely getting weak, and could stand to be replaced (capacitor technology has come a long way in 50 years and this will also improve performance). See if you can get a schematic and post it here. Take some pictures of the thing with the cover off. Also post the tube types here. You'll love listening to a pair of ultra-linear pentodes in push-pull combination...
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