Quote:
Originally Posted by VintagePC
Interesting approach, if I could find such a control for my own set I'd consider doing that modification. As it currently stands I just crank the brightness before power-off so that the dot "dissipates" quickly and doesn't do any gradual phosphor damage. 
I could also see a failed switch there being the cause of many a serviceman headache for no picture on screen... IIRC other cathode-driven sets use a large-ish capacitor to B+ so it gets slammed hard DC negative on power-off and by the time it's discharged the emission has dropped enough that the dot is dim or completely gone. |
You could duplicate that design by making the brightness switch a relay with a 6 volt coil fed by the filament supply if it is a transformer powered set... Just remember if you can't get a 6VAC coil rely you will need to rectify the filaments for 6VDC.