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  #57  
Old 03-26-2011, 11:32 PM
DaveWM DaveWM is offline
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Join Date: Feb 2009
Location: Orlando FL
Posts: 5,607
yea I think I am getting close to the issue on my setup, see my post in the noisey pic thread. pretty sure it is cathode voltage issue from the video out tube (plate V to high, look like the video out 12GN7 tube cathode bias resistor/pot drifted up, causeing the tube to not conduct enough, resulting in the high plate voltage).

Yes I did clean front panel control pots, but for the IF trim pot on the video board (missed that one), and yes I agree the pots on the back are cheap a$$ stuff.

I am pretty sure this last resistor (the R61 100 ohm on the bottom of the brightness control) is going to be the one that fixes my dim pic. I did check the cathode bypass cap, its ok, so that being ok and the resistance check of pin 1 of the 12GN7 (like 500 ohms was the MIN I could get, should have been 100 with the pot cranked fully towards ground) I think I got it.
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