[RodB]

I think you can check pin 5 of the 6A8 for a small negative voltage to see if the oscillator is running. If its not, with the power off and broadcast selected you can monitor pin 5 to ground with an ohmmeter and move the tuning condenser through it's full range. You should see a reading of about 33K with no movement in the meter. If the meter reads zero or moves off 33K the tuning condenser oscillator plates are shorting.

Rod