Freq2002,
just to make sure that it is clear, there is no problem using positive or negative ground on these old tube models. However if the vibrator has been replaced with a solid state one then the vibrator has to be the correct polarity. With the 47 to 53 radios, a resistor of around 1 ohm and a rating of about 40 watts does the job. I don't know the actual draw on the 54 radio but it probably would be slightly less .
