Quote:
Originally Posted by bandersen
My best guess is that every time the set was turned off the raster collapsed to a bright spot in the same area. Also maybe a manufacturing or rebuild defect.
|
Bob, I think you guessed it! On shut off, the raster first snaps to a horozontal line, which then collapses to a bright point.......(I've observed this on many old sets; filter caps in the power supply draining off?), and danged if it is not in the same neighborhood as that smudge!
So how about a piggybacked pre-switch of sorts to cut the filament to the horozontal OP tube, before powering down the whole set? Or perhaps switching the hi-voltage off somehow before turning the power switch? With good 12LP4's not extinct, but not exactly growing on trees, I'd like to preserve this one as long as possible!