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What to do with old vacuum tubes? Answered

I recently found a really old tv in a crawlspace at work and I brought it home and salvaged 13 vacuum tubes out of it. I figured I could make some sort of cool project out of them like maybe a mad scientist lamp with LEDs or something. But before I actually start using them I wanted to brainstorm some more ideas of possible projects. So if anybody has any good ideas of cool things to do with vacuum tubes, let me know. Also, just out of a nerdy curiosity I was wondering what exactly vacuum tubes are designed to do, does anyone know?


a vacuum tube can be used both as an amplifier or as a rectifier. It amplifies by using a filament much like in an incandescent light bulb by heating the cathode(-) it will knock of electrons which have a negative charge. These electrons are attracted to the anode(+). In this process it will be able to amplify the voltage given to it. The hotter the filament the more elecrepes emitted the higher the voltage.

what kind are they? guitar amp comes to mind

please please grab that tv or send it to me because i love old tube raqdios tv ext


9 years ago

You could give it to me. As i cannot afford one.

You can make some pretty cool magnets with them.

Yeah, with the little ones. I wouldn't suggest it with the biggest tube though.

I keep a few around home (since I still have an old tube AM radio) as well as the ones used for the bridge of that same radio (I had to fix my wife's grandmother's radio a few times). What I would love to get a hold of would be a few of the Nixie tubes (like the GN-4). :-)


9 years ago

Vacuum tubes are roughly analogous to the modern transistor. In a general sense, they are used as a valve that controls the flow of electrical current (in fact, the British term for vacuum tubes is valve.)

Here's a nice explaination on how they work.

You can certainly build something, but there are some caveats...

They are high-voltage devices (and power tubes are high-current), so there's some inherent danger. Most of the tubes in a TV are RF (high-frequency) and aren't always usable for simple projects.

But the TV will also have a moderately-HV power transformer, and that is a very handy thing...

There's a Vacuum Tube Group here on Instructables, too.

I'm not really much of an audiohead, radios made with normal transistors sound just fine to me, but I really like making cool lights so I was hoping I could make some sort of lamp out of these. Is is possible to make them light up using their own circuitry or would I be better off drilling a hole in the bottom and inserting an LED or something?

try to link them to a camera flash circuit without the capacitor you can also pulse into them with a starter from lighter / bbq if they are gas filled youll likely see colors etc if anyone wanna try this without valves - get a new (or one that had not been used much) fluorescent lamp starter and use the discharge lamp thats inside

get the flash circuit from a used single used single use flash camera (a photo shop can give you a lot of them for free) in the circuit there is a big capacitor sticking to the side remove it (trying not to get shocked by the way) and connect the lamp instead insert battery and push the charge button try with lamp from fluorescent starter first. that works for sure. see what happens so youll know what to expect from the tv lamps in the tv lamps try all possible selections of 2 entries and try each pair in both directions of + -

If you try to induce old TV tubes to "arc" just for visual effect (or for that matter to operate in their intended fashion), you should be aware that X-ray emission was an unwanted byproduct of many 50's and 60's TV set tubes.

Here's a reference, and another, and another.

"Arcing" a tube will ruin it, too (yes, I know--not a biggie if you only care about how it looks, not how it operates...)

The filaments themselves aren't very bright; you'll burn 'em out if you push too hard. I have seen people mount LEDs beneath the sockets to illuminate the tubes in a more *spectacular* fashion... (i.e., not that spectacular.)

For a project, how about something like Rasputin's "summoning glove" from Hellboy?


you can use the audio amp circuit from the tv as is