[Tim Tress]

As with any car radio from the 1930s to the mid/late 1950s, the paper and electrolytic capacitors will need replacement. The most critical one is the "buffer" capacitor, across the secondary of the power transformer. It should be replaced with the same value, and the voltage rating will be high; usually 1000 or 1600 volts. The electrolytic capacitors and audio coupling capacitors are also important, as leakage there will load down the power supply and cause damage to the transformer and vibrator.

These 6 volt vibrator type radios draw 6-8 amperes or more, so you will need a power supply capable of delivering that for bench testing. Radios with solenoid operated tuners will draw even more when the tuner operates.