It might be too soon to consider the innards of the old CRT monitor at the back of your closet to be something worth putting on display in your home or workshop. For that curio cabinet-worthy appeal, you need to look a bit further back. Say, about 150 years. Yes, that’ll do. A Crookes tube, the original electron beam-forming vacuum tube of glass, invented by Sir William Crookes et al. in the late 19th century, is what you need.
And a Crookes tube is what [Markus Bindhammer] found on AliExpress one day. He felt that piece of historic lab equipment was asking to be put on display in proper fashion. So he set to work crafting a wooden stand for it out of a repurposed candlestick, a nice piece of scrap oak, and some brass feet giving it that antique mad-scientist feel.
After connecting a high voltage generator and switch, the Crookes tube should have been all set, but nothing happened when it was powered up. It turned out that a capacitance issue was preventing the tube from springing to life. Wrapping the cathode end of the tube in aluminum foil, [Markus] formed what is effectively a Leyden jar, and that was the trick that kicked things into action.
As of this writing, there are no longer any Crookes tubes that we could find on AliExpress, so you’ll have to look elsewhere if you’re interested in showing off your own 19th century electron-streaming experiment. Check out the Crookes Radiometer for some more of Sir Williams Crookes’s science inside blown glass.
Marb’s videos always are a delight! I miss playing with these devices during my early studies at uni learning first order principles. In didactics it is so important to first start by visual learning to spark the curiosity in students: “Okay professor, I want to understand this now!”
Sometimes it would be a joy to be young again just to re-discover everything, or to be a teacher with good students.
Agreed, I feel that
Crookes tubes are still available on AliExpress. You need to search for “cathode ray tubes”. I bought mine here: https://de.aliexpress.com/item/32851034247.html
Too soon for crt bits as decoration? Nah not if they’re strange enough and presented properly, like this one. I have a big orange radar tube somewhere that I need to turn into an objet d’art
Oohhh, I got one of these, gifted to me by a friend working at a University who saved it from the dumpster.
I also got one that has a panel along the length of the electrom beam that shows a blue line that you can deflect up and down with magnets.
I’ll have to get a power supply built for them, maybe I can repurpose a He-Ne laser supply, I have some of those somewhere around here…