Quote:
Originally Posted by W4rtc
...the coating is peeling off the crt. That could be a problem.
Joe
|
Yeah, the inner and outer coatings of the CRT form the plates of a capacitor which is the filter cap for the HV supply itself. If the outer (negative) coating loses its ground connection, the HV loses its filtering. This can allow the HV to fluctuate instantaneously with beam current. Sometimes there's also arcing from the 'dag to ground, and this can be picked up in the RF or IF chains, further screwing with the pic.