On 08/28/2013 01:28 PM, Dalibor Farný wrote: > 2013/8/28 NeonJohn <j...@neon-john.com>: >> I blow glass and make neon as hobbies and am the chief engineer at >> Fluxeon which makes induction heaters, useful for heating the internals >> of a vacuum tube to outgas them so maybe I can throw in here a bit. > > Great info, I just need one RF heater ;-)
Here's my open-source heater page. http://www.neon-john.net/Induction/Roy/Roy.htm If you don't have the time nor inclination to do it from scratch, here's that same heater in kit form http://www.fluxeon.com/Roy1200.html > - , mostly lead glass as this achieve high viscosity at low > temperatures, hard to find and impractical for hand making (tends to > crack.) I like leaded glass MUCH better than any other formulation. It's liquidus stage is wide, requires little to no annealing and as you note, sticks to dumet (or even just plain old copper) just fine. The enviro-nazis have made manufacturing lead glass tube very difficult so it's practically unavailable. Last time I heard, there's a factory in the Czech Republic still making it. The neon and related industries are now stuck with lead-free glass. It has the same coefficient of expansion as lead glass and seals to dumet but it has a much narrower liquidus range so it's significantly more difficult to work with. Plus its melting point is high enough that it produces copious sodium flare, requiring didydmium glasses. In Europe, the glass is available from Tecnolux in Germany. I don't like their glass but the one I do like (FMC) is US made and may not be available in Europe. > the atmosphere (composition and pressure) > around 0.1 - 0.001% of Argon with Neon, total pressure around 20torr > and higher, lower pressure means that numbers becomes fuzzy. In latest > tubes is also a mercury present, the amount is not critical. Only > thing I dont know is whether the mercury has an impact on breakdown > voltage.. That "around" thing is the problem. I'm sure lots of research went in to perfecting the gas mixture and pressure, something I don't think you want to have to duplicate, thus the suggestion to have a known long-lived one analyzed. A wide range of pressures will "work" but the lifetime looks like an upside-down "U" around the optimum pressure. For example, I can load a 15mm tube with anywhere from about 2 Torr to 20 Torr but the long life point is 12 Torr for short tubes and 8 Torr for long ones. At least with neon, the mercury does not affect the voltage drop across the tube. The argon/neon ratio is the primary determinant. > I think that there wont be demand for mass producing nixie tubes > anymore.. I will focus on hand making tubes that are absolutely unique > and manufactured precisely to smallest detail, making own clocks in > the future. This is the only way I see.. There'll be the typical inverse price/demand curve but I bet that if the cost of tubes could be brought down to under $5 through mass manufacturing, there would be a large demand. Nostalga is in. Plus the Nixie is still the easiest display technology to read. Just my opinions, of course. John -- John DeArmond Tellico Plains, Occupied TN http://www.fluxeon.com <-- THE source for induction heaters http://www.neon-john.com <-- email from here http://www.johndearmond.com <-- Best damned Blog on the net PGP key: wwwkeys.pgp.net: BCB68D77 -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/521E3FFE.3070604%40neon-john.com. For more options, visit https://groups.google.com/groups/opt_out.
