|
The heater is shorted, trying to blast it out could open the heater killing the tube for good. In any case the heater is insulated from the cathode by a thin layer of insulating material, if it's shorting then the coating is gone or thin in a spot, blasting it with high voltage will only knock more of it off or weld the heater to the cathode.
Much better to just add a separate filament transformer, they are small and can be mounted discreetly under the chassis.
It's not a bad idea to use a transformer on a series string set in any case to protect the CRT from turn on surge, a lot of people do this on the Pilot 3" sets because the tubes are nearly impossible to find.
|