Making glass-to-metal seals for homemade vacuum tubes
maurycyz.com - 71 poäng - 24 kommentarer - 95331 sekunder sedan
Kommentarer (6)
- tliltocatl - 430 sekunder sedanOne thing about gallium/galinstan - it would actually make a descent high vacuum seal as it has lowest vapor pressure of all elements - so it doesn't evaporate. The problem is that it sticks to just about everything that isn't PE/PTFE. Galinstan thermometers use some proprietary coating to make glass repel it.
I was once entertaining the idea of using gallium for an electrostatically or MHD boosted Sprengel pump, but figured out sticking would make it infeasible. And now it's unobitanium too.
- tyingq - 1982 sekunder sedanThe research here is clearly interesting, but if you just need to get something like this working, premade neon tube electrodes are plentiful and inexpensive.
- alister - 8002 sekunder sedanWhat was the large-scale commercial procedure for making electrodes that pass through the glass without letting air in? I assume that electronics manufacturers must have been making millions of such vacuum tubes in the past. Is the knowledge lost (or not practical for hobby use)?
- projektfu - 8488 sekunder sedanI was wondering about the feasibilty of this, but I thought that useful tubes needed a harder vacuum than that. Is this really "good enough" for a triode?
I figured the wire-holding/element-holding aspect of a standard tube was in the base, and the glass-to-base seal is the important part. You can have a less-hot metal holding the filament and penetrating through the base. But I haven't looked carefully. These are my off-the-top-of-my-head thoughts about it.
- LgWoodenBadger - 4081 sekunder sedanWould you be able to reseal the cracked glass and regenerate the vacuum through the other end?
More glass, epoxy, or similar?
- smlacy - 8048 sekunder sedanHmmmm. Wonder if you could just induct through the glass with coils on each side? Seems perfect for high voltage applications?
Nördnytt! 🤓