Strong NOS! Mutual Conductance (GM)Test: 79 & 72 ( 58 = NOS AVERAGE & 38 = Good MINIMUM). Test results will vary between testers as it is not an exact science. I also use variac at 120 volts with my testers.
Item Tag: Barber Colman
Barber Colman Controller Tube 5608A Wheelco Instruments
Don’t miss out on the opportunity to own this rare and valuable piece of history.