Glowing mercury thyratrons: inside a 1940s Teletype switching power supply

Re:Glowing mercury thyratrons: inside a 1940s Teletype switc... by tlb on Monday September 10, 2018 @01:14PM (#17953317)

Mercury rectifiers are beautiful. I once built a vacuum tube audio amplifier with directly heated triodes and mercury rectifiers, aiming for a symmetrical orange-blue-blue-orange glow.

It turned out that mercury rectifiers make a lot of electrical noise when they switch, so there was an annoying 120 Hz buzzing noise. But it did look cool.

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Re:Glowing mercury thyratrons: inside a 1940s Teletype switc... by dekhn on Monday September 10, 2018 @01:18PM (#17953362)

I recently built a "vacuum tube nightlight" (http://www.electronixandmore.com/projects/vrtubenightlight/i...) because I thought the plasma tubes give off such a nice glow. But they aren't very bright and it's hard to see the plasma; these rectifiers are way more attractive but I can't bring myself to work with them.

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Re:Glowing mercury thyratrons: inside a 1940s Teletype switc... by planteen on Monday September 10, 2018 @01:45PM (#17953538)

> these rectifiers are way more attractive but I can't bring myself to work with them.

Cool project! Do you say you can't bring yourself to work with them for safety reasons (as in, I imagine mercury vapor is very dangerous if it escapes the tube) or is there another reason?

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Re:Glowing mercury thyratrons: inside a 1940s Teletype switc... by dekhn on Monday September 10, 2018 @04:01PM (#17954714)

just the mercury vapor being dangerous.

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Re:Glowing mercury thyratrons: inside a 1940s Teletype switc... by antiphase on Monday September 10, 2018 @06:19PM (#17955677)

More likely that it generates a massive amount of wideband noise that happens to be modulated at 120Hz in this case.

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