Quote:
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....?
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NOT special, and usually used to death, with lettering permanently burned into the phosphors. Why not special? because CRTs by their nature are always in wear-out mode. Anything that could improve their life would be applied to home sets too (not necessarily to get longer life, but perhaps better spot size by using a smaller cathode, or some other trade-off).
Wear-out mode:
The life of components exhibits a "bathtub" curve with three parts: infant mortality (high rate of failure for defectives), normal use (low rate of uniform random failures), and end of life increasing rate of failure (wear-out failure). CRTs, however, are in the wear-out mode from the start as the cathode is continuously degrading, as well as the lesser problem of the phosphor burn continually accumulating.
Electrolytic capacitors can be similar if subject to high temperatures.