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Old 05-01-2014, 01:35 PM
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VintagePC VintagePC is offline
Tube bug got me 05/2010
 
Join Date: May 2010
Posts: 535
Quote:
There is an extra switch ganged with the power switch that disconnects the brightness control,
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.
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