Crt cathode meterial

[N2IXK]

I would suspect average receiving tube life to be substantially less than 10,000 hours.

Tubes with a 10,000 hour guaranteed life were available (RCA "Special Red", Mullard "10M series", etc.), but they were expensive premium stuff reserved for critical industrial/military applications.

[miniman82]

No, no and no.

Won't work without a getter, cesium is not part of the equation, and there's nothing you can do to reactivate a cathode or getter once fired/activated.

This question belongs in the rebuilding forum anyway, perhaps a mod can move it.

[benman94]

DuMont rated the 20BP4, 15AP4, and 12JP4 CRTs at about 5000 hours life. This would correspond to 5-6 years, if used for 3 hours a day 300 days per year. That seems about par for the course based on CRT replacement tags I've seen.