Gregory's ServerTektronix used to have their own CRT fabrication shop (the Engineering Tube Lab) for building prototypes for oscilloscopes under development. apparently, as a joke, they made two CRTs out of old coke bottles. named the Coketron, natch.
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@byteshift69 fully functional. they coated the inside at the end with phosphor (can't see it in the B&W photo) you don't need post deflection acceleration for a demo like this. shadow mask only needed for color CRTs. 
Григорий Клюшников
Ones made out of green or brown beer bottles, with matching color of phosphor, would look cool af
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@North there's some discussions of the challenges at https://groups.io/g/TekScopes/topic/coketron_the_real_story/79701930. the seal between the coke bottle (soda glass?) and the borosilicate tube with the electron gun is...tricky.
Nick Poole
@tubetime oh, yeah, if you don't build your own electron gun. Just make it out of soda lime glass with dumet seals. I think I'll try to do a working CRT out of Boro first before I face the challenge of working soft glass, though.
Adam Burns
@tubetime In 2018, The mayor of Weisswasser, Germany took me on a tour of the old Telux glass factory where they made light bulbs, valves, and early television tubes, which were circular like scopes, not square. This is a press used in the early TV tube manufacturing process.   |
@tubetime I assume these aren't functional, because there's no anode, aquadag, shadow mask, or phosphor.