Conserving our good CRT's

[ChrisW6ATV]

Originally Posted by Username1

I think its beam current, or cathode current (excessive brightness) that kills them....
Anyone know if old airline terminal screens had anything special about the crt's?
Those tubes had to run at higher than home living room brightness..... Were they special....?

I still support some CRT displays in airports (and have been doing so for over 30 years), and I am not aware of the CRTs being more "heavy duty" than standard tubes. Some of the monitors I work on have been in service themselves for over 30 years, but few likely still have their original CRTs, though it is possible. I have done rejuvenations on many of them, and it often gives the tube new life that can last for years.

Originally Posted by earlyfilm

I scrounged an old 6.3 volt transformer from my junk box and wired the CRT to be on 100% of the time... We used this set operating the filament at its rated voltage and always on when the set was off for about 10 years!

Earlyfilm's technique is the key to the CRTs lasting for decades in airports. The monitors are almost always on 24 hours per day, and when I shut one off for repairs, it can take 5 minutes sometimes to even see visible light on the screen afterward, but after 30 minutes they can look nearly new and stay that way.

I also agree that it is the cathode/beam current ability that limits the life of CRTs, not the heat (as decided by the heater voltage). Monitors that are used at high brightness and contrast settings have always had their tubes fail sooner than those we could keep at lower settings.