[radiotvnut]

That 1980 RCA console I just got uses a 25VEZP22 delta-gun tube. Just out of curiosity, I looked up that type in my tube substitution book and it list no subs. So, I wonder what is supposed to be so special about that tube?

During my used TV selling days, I did lots of tube swaps with other types that technically were not listed as a substitute. If the tube would physically fit in the set, if the gun structure was the same, if the yoke would fit properly on the neck, and if the socket was the same, then it would generally work.

As far as those late '70s RCA consoles that had somewhat lousy tubes, I've been known to stick Zenith Chromacolor II tubes in those (which was probably an improvement). The Sylvania black-faced jug was probably the best looking delta-gun tube from anybody, but those didn't always have a very long lifespan. The 1970s Zenith delta-gun jugs almost never die.