The Stovebolt Site Forums The Shop Area The Electrical Bay The Radio Bench is it possible

to convert a positive ground radio to negative? it is in my 1960 mga.

WE b,

If I was a betting man, I would bet "no". However, I located a document that I think will help you address the issue.

Good Luck,
Dale

Even thought I said no... We all know with enough time and/or money anything is possible.

The mg has been negative ground for all most as long as i have had it, 42 years after i bought a new battery and was stuck on the road in DEC. 1968 and they installed it backwards and i could not figure out why until i took it to a shop and they told me why so just left it that way. the radio i installed a few years back was cheap and a cassette player. i was just thinking which is dangerous for me that i could do what i did in 54 get this one done over and have the mp3 or i pod capability. Thanks for the response. ron

If your radio has transistors in it, which I would think it does, you cannot convert it. There may be some 12 to 12v polarity converters on the market that could be used.

What was the reason they gave you for switching it back?

In the early days of transistone auto radios there where radios with switches to convert from negitive ground to positive ground , very few imported cars and trucks had radios in them at that time,many USA radio manufactors made radios for these imports, I have a MOTOROLA built radio for a late 50's Volvo, it even has "VOLVO" on the dial .
I have a transitor[hybred] Stromgburg Calson 12volt + or - ground and I've also have two Mack truck radios ,transistor , that can also be played on + or - ground .

Bill,
how exactly do they do that?

Bill,
I guess I was asking about the details on how they did that. I would assume that they used a pc board that was isolated from the case and then the polarity could be switched. Is that how it was designed?

Fred

I took one of the MACK radios apart ,{I could get it going if someone out there wanted one}, the chassie and output are insulated from the case, transistors will burn out if polarity is wrong. The old vibrator sets the one's with the sychronce vibrators, used in 30's and 40's Buicks and others ,will not play on the wrong polarity, but will not burn out , I've had 1930's auto sets that have reaversable polarity switch, wires and vibrators , the reason these old truck radios will work with either positive or negative ground,when equiped with original vibrator, is that the only thing the 6 volt line runs is the tube filament and the power supply witch converts the DC voltage to AC voltage , then it is jumped to 250+ volt and rectified using the correct polarity for your B voltage

My A is neg ground with a Panasonic radio with mp3. Are you putting the original radio back in. I just installed a delco alternator in the MGA last week and it may be the best upgrade I have done. I have been forced back into the MG for a few weeks while my brother is driving my X90. I had forgotten how hot the A can get when it is 95 degrees outside.