There's a few Russian companies that manufacture vacuum tubes, some even make them to order. A friend of mine wanted to make a valve amplifier that actually produced high quality audio and designed a valve that met hit criteria. He's using one of these companies to make it :-)
The caption says there's a CRT in the upper right corner of the capacitance bridge panel in image 13, but is it really? I have a hunch it's just a little screen over the top of a 6E5 "magic eye" tube but I could be wrong, those were quite common on test equipment of that vintage and function. Basically it's a replacement for a meter when all you needed was an indication of an analog null condition, like showing that the bridge was properly in balance.
I worked on a lot of old equipment, and it all had the same problem, it was unreliable, drifted like crazy and NEDED calibration to attain what are now considered mediocre specs. These days any voltmeter from a company like Fluke etc. that is ~1% accurate usually doesn't need calibration, we just do it because the standards say so. Get to 0.1% and you occassionally need calibration. Things sure have improved
NASA's Orion Flight Software Production Systems Manager Darrel G. Raines joins Planet Analog Editor Steve Taranovich and Embedded.com Editor Max Maxfield to talk about embedded flight software used in Orion Spacecraft, part of NASA's Mars mission. Live radio show and live chat. Get your questions ready.
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