Quote:
Originally Posted by Boom
You are far more likely to get a screen damaged by Ion burn than an open heater. This is something you won't see until you have restored the set and all timbases etc are running.
|
I agree with this. Most but not all of the troubled CRT's I have, the gun still has reasonable emission, they have either gone soft focus or the phosphor is ion burnt or has simply darkened and lost efficiency all over, this is easy to see on round face tubes where the raster was scanned and some unused phosphor at the periphery is still normal.
This is why a tube gun rebuilding service on its own is only a partial solution, the tubes to be re-built properly must be re-screened.
I once attempted to re-screen a CRT myself, but it failed. But over 25 years ago now the particular tube, a 12LP4 was re-screened and re-gunned, by Thomas Electronics in the USA, they aluminized it too, turning it into a 12kP4. I didn't know how lucky I was at the time that the service existed.