Mystery foot-long thick-glass discharge tubes? - Page 1
Forum section: electronics / general

author: Whales
author_rank: Super Contributor
timestamp: January 06, 2018, 01:02:30 am
content: I have had these sitting around for years, no idea what they are. Does anyone know?Glass is not uranic (does not glow under UV light)Holes in the end of the terminals do not go through into the tubes themselves, I've tested with water.Electrodes inside the tube have roughly machined surfaces

author: cdev
author_rank: Super Contributor
timestamp: January 06, 2018, 02:11:32 am
content: Have you applied a high voltage to one side of them with the other side grounded? Something like an air ionizer transformer perhaps?Just to see if it causes a typical gas discharge phenomena and if it does, what spectra it is.(That may be able to tell you quite a bit about what may be in there)Also, as you implied in your sig, there is a chance its potentially hazardous so go very easy on the voltage you apply, make sure its not enough to cause any problems. I have no idea what that would entail so - hopefully other people here are more knowledgeable than me.Some gas discharge phenomena if you can precisely adjust the votage to get it just right, are just gorgeous.. quite beautiful, quite colorful..

author: Whales
author_rank: Super Contributor
timestamp: January 06, 2018, 09:09:26 am
content: Unfortunately the most HV thing I have is a toy plasma globe. I'll try using it close and see what else I can scavenge.I'm only guessing that they are discharge tubes -- the really thick glass seems odd to me.QuoteNot sure what diodes have to do with discharge tubes

author: Whales
author_rank: Super Contributor
timestamp: January 06, 2018, 09:14:13 am
content: No reaction to a plasma globe, so if these are discharge tubes then they're much harder to break down than an ordinary fluoro tube.Could these be lightning arrestors? Would there be a purpose to them having such thick glass in this situation (eg to avoid exploding)?

author: tautech
author_rank: Super Contributor
timestamp: January 06, 2018, 09:28:00 am
content: What's the white diecast fitting on one end ?Better pic of that might give more clues.I looked at these pics earlier andall day. Another look and spotting the washers on the shafts makes me wonder if they weren't rollers in some sort of roller bed that needed HV insulation.Are the marks on the metal shafts indicative of lots of rotations and the shims/washers to keep the roller central in a frame ?

author: Whales
author_rank: Super Contributor
timestamp: January 06, 2018, 10:01:25 am
content: White cast fitting:Non-magneticSofter than my file but does not react to vinegar.The white is paintEither pinned to the main rod or screwed to it (with the screw heads cut off so it looks pinned). Very secure, does not wiggle.Hole in the end is straight through, does not T-off or intersect anything else.Washers:One aluminium + one steelLoose but contained within their stretch of steel rod by the end fitting

author: capt bullshot
author_rank: Super Contributor
timestamp: January 06, 2018, 11:20:02 am
content: Xenon Flash tubes for exciting a ruby laser?Usually this stuff is water cooled in some way. I've never seen the innards of such a laser unit, but for no particular reason this came to my mind.

author: Gyro
author_rank: Super Contributor
timestamp: January 06, 2018, 01:28:56 pm
content: Quote from: Whales on January 06, 2018, 09:14:13 amIn the absence of any better ideas, yes, I'd go for lightning arrestors, or at least HV surge arrestors of some kind. The electrode faces look designed for high current, probably Tungsten and it would certainly explain the thick glass.Edit: Either that or high power discharge lamps - AC because the electrodes are symetrical. I would expect more complicated electrode structures than that though. Discharge lamps usually have structures designed to get hot (to improve emission) something like a rod with a helical coil of Tungsten wire wound around it. Those electrodes look designed to stay as cold as possible.

author: amyk
author_rank: Super Contributor
timestamp: January 06, 2018, 06:08:52 pm
content: They don't look very electrical to me --- I agree with the other suggestion about these being mechanical rollers of some sort. Even the extremely-high-pressure xenon short-arc lamps don't have glass that thick. There's also a lack of any evacuating pip.

author: station240
author_rank: Unknown
timestamp: January 06, 2018, 07:32:58 pm
content: No one would use steel rod as electrical connections, also the wear marks at both ends prove they were rotating parts.Perhaps glass rollers from some form of printing press.

author: SeanB
author_rank: Super Contributor
timestamp: January 06, 2018, 07:47:30 pm
content: Ink rollers from a printing press, the zinc alloy fitting at the one end is where the drive dog was attached, using a pin drive.

author: Gyro
author_rank: Super Contributor
timestamp: January 06, 2018, 08:14:51 pm
content: Wouldn't they have run the shaft right through the glass roller in that case? The radial (bending) load on the relatively short glass-metal 'seal' at each end looks like a serious weakness to me.Edit: Looking a bit closer, are those rubber/canvas 'seals'?

author: Cyberdragon
author_rank: Super Contributor
timestamp: January 06, 2018, 11:59:48 pm
content: These are definitely not lightning arresters. If they are, they're naked and missing their sleeves. Long lightning arresters are supposed to have insulating rings around the outside, and these are smooth. There are a few large ridge-less lightning arresters, but they look more complex and nothing like this.They might be rollers, but then again, why would one of them have that odd bracket thing? That bracket could be some sort of crank coupling to move the roller back an forth, perhaps to eject the paper or other material. I don't know why they'd be glass either, maybe for cleaning or chemical resistance.

author: stj
author_rank: Super Contributor
timestamp: January 07, 2018, 02:53:46 am
content: looks like plumbing to me, maybe you feed it with RF or microwaves etc down the guide and it excites a gas in the tube.whatever it is, i wouldnt want to fire it - with glass that thick the energy pulse would probably be huge.infact it does not look like glass, it has a slight spectral shift that reminds me of quartz lamps.

author: Whales
author_rank: Super Contributor
timestamp: January 07, 2018, 07:31:13 am
content: Thankyou everyone for your thoughts.@non-lightning thoughts from several of you: Roller marks, wrong materials, wrong shape, etc. Indeed looks unlikely now, thankyou.QuoteIt sounds like you have seen one of these before. Any idea what I should search for to get pictures?QuoteYes it looks like the black is rubber-like, I just gave it a poke with some sharp points.The yellow material appears to be rubbery (not canvas) too and it's soft enough I can pick a little bit out. Possibly an adhesive.QuoteHehehe -- Iwillresist putting this in the microwave. That and the fact it's too long.

author: SeanB
author_rank: Super Contributor
timestamp: January 07, 2018, 09:33:02 am
content: Yes, used to have an AM international offset printing press at work with a set of glass rollers as part of the ink system, used between the rubber rollers for certain ink types to get a very even spread across the plate. Those were part of the second ink head we got for it to do 2 colour jobs.

author: Gyro
author_rank: Super Contributor
timestamp: January 07, 2018, 10:59:12 am
content: They'd make very nice rolling pins for the kitchen.

author: cdev
author_rank: Super Contributor
timestamp: January 07, 2018, 02:07:21 pm
content: Ink rollers sounds about right, and they could be clear so you could see any speck of ink or dirt to clean it off?

author: Whales
author_rank: Super Contributor
timestamp: January 07, 2018, 08:42:19 pm
content: Quote from: SeanB on January 07, 2018, 09:33:02 amThankyou SeanBI think I will be cleaning them up and using them as rolling pins, until Those Predecessors Who Must Be Obeyed try to throw them at me.