That is a glaring error for someone who is moderating the electrical forum. Anyway, I have a GMC radio and it never consumed more than 6 amps once warmed up. The best solution, if you don't want to convert to 12 volt, is a DC to DC convertor. Using transistors, it very efficiently converts the 12 volts to 6 volts. I have been searching the surplus catalogs but haven't found one yet. This might be good product idea for someone with an entreprenurial spirit. Another option would be to use a series string of silicon diodes. The forward resistance drop is usually 0.7 volts so you could use 10 diodes in series. You may have to play around with the number of diodes since the voltage drop varies somewhat with temperature and the type of diode but it should be better than a resistor. It should also be mentioned that while the filament voltage of the tubes in auto radios has been reported to have a larger tolerance compared to typical tubes, operating above rated voltage (6.3 volts) will DRASTICALLY reduce tube life. Slightly decreasing voltage will usually increase tube life while only margially reducing transconductance. This is just something to be remembered when using resistors to adapt 6 volt radios to 12 volt systems. There have also been some people spending exhorbitant amounts of money on tubes and vibrators for these radios. Antique Electronic Supply (
www.tubesandmore.com) has decent prices on tubes, vibrators, and high voltage capacitors. Fair Radio Sales also has good prices on tubes (you'll have to search for the web address.) Mouser Electronics (
www.mouser.com) and Digikey (
www.digikey.com) have more standard components (resistors, capacitors, etc.) I have no financial connection with these suppliers, I am just a satisfied customer. There are others, shop around. If you can rebuild engines, you can fix an old radio.
