Don,
here is one thread that I saved:
http://www.stovebolt.com/bboard/cgi-bin//ultimatebb.cgi?ubb=get_topic;f=3;t=001997#000000
Some folks don't like the idea of running a radio on a resistor. In general it should not be a problem. However, if one or two tubes were to fail, the radio would see a higher voltage across it's terminals and this could hasten the failure of all the tubes.
A resistor just sits inline with the radio and causes a voltage drop, creating heat at the same time. Variations in the system voltage will show up at the radio with this scheme. On the other hand, a regulator has terminals that are connected between the supply and ground. A third terminal supplies the 6 v load and this stays at 6 volts as long as the system (generator) voltage is above 6 volts.
Fred
