Some of those (KV-1212) I have seen operating over 20 years later - dunno their daily avge. usage - but of these a few had reached the poor-contrast stage. That seemed to be as much about gas as emission, but then all interact - the gas increases drain which asks more of the cathode and of HV current. Death spiral eventually.

The mission for an oscilloscope CRT is simpler (if more precise re beam dynamics). I have a number of scopes whose CRTs are now from 20 to near 40 years of age. (For the ones I have - the rest is (mostly) solid state) Their 'getters' worked/work well and the beam is as crisp as new on most. Of course these were made in Tektronix' own tube fab, state-of-the-art when that meant something -- it will be interesting to see if (like the occasional light bulb) -- some of these are still operating in 50 years. I'd bet a few bucks: they will. (Electrolytic caps will have been replaced, natch)

We'll never again see analog scopes of this quality, though there is one very expensive ('image-tube' + LCD final display) modern scope in production - which can sorta compete on writing rate = 550 MHz BW IIRC. Still doesn't equal the GHz Teks which shall eventually lose their emission, when used daily. (Most folks reserve these for tough jobs and do Not leave them on for routine stuff - but some Corp users don't care.)

Odd to see a scientific tool of undoubted utility: just disappear through [??] = with NO replacement in sight.


Ashton