Comment by Physkal
11 hours ago
How feasible is it to make a crt from parts? I find crt's fascinating learn best by doing- I at least want to demonstrate horizontal and vertical sweeps. But I've never seen a DIY CRT kit before.
11 hours ago
How feasible is it to make a crt from parts? I find crt's fascinating learn best by doing- I at least want to demonstrate horizontal and vertical sweeps. But I've never seen a DIY CRT kit before.
> How feasible is it to make a crt from parts? [...] I've never seen a DIY CRT kit before.
The closest thing that springs to mind: A friend of mine once drilled a hole into an empty Vodka bottle, stuck two wires in it (one at each end), a hose adapter for a vacuum pump, "sealed" the whole thing with a hot glue gun and hooked it up to several scavenged microwave oven transformers in series. Yes, the output was rectified and capacitors were also involved.
Here are some pictures:
https://chaos.social/@itsyndikat/107846783094589995
IIRC what he wanted to do was plasma etching.
I suppose rearranging the electrodes (using a piece of sheet metal with a hole in it; both fed through the neck of the bottle) and wrapping the sides of the bottle with 4 strips of aluminium foil could get you a beam and some crude deflection control. Not sure tough what you would coat the end of the bottle with, but I guess vacuum coating would be applicable.
If that sounds absolutely insane to you, I'd wholeheartedly agree.
At least to my ears, trying to build a CRT from first principles, combined with learning-by-doing and learning-EE-from-youtube-tutorials, sounds like a fast path to end up either dead or in a permanent care facility. Not exactly something I'd hand out in beginner-friendly kit form.
This person scraped phosphor out of a broken fluorescent tube and made several experimental CRTs: https://www.sparkbangbuzz.com/crt/crt6.htm
From the site: "The cathode ray tubes that I am describing here are crude and they are relatively easy to make at home. They are in fact, much easier to build than most technically minded people would ever imagine."
In some ways it's never been easier to get all the equipment you will need. But if you're wanting to make ones even half as good as the ones on this page, you'd probably want to become a skilled glassblower and outfit a lab that looks something like this:
https://www.youtube.com/watch?v=wxL4ElboiuA
The parts for making neon signs are not as uncommon and it would be kind of an introductory approach to building the skill necessary for more complex electron tubes.