2013/8/28 NeonJohn <j...@neon-john.com>: > > > On 08/28/2013 01:28 PM, Dalibor Farný wrote: >> 2013/8/28 NeonJohn <j...@neon-john.com>: > 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.
I know only about companies producing leaded glass for bowls and other decorative glass.. Not tubing.. > >> 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. There is detailed graph of pressure and breakdown voltage for different NeAr mixtures, but generally everything below 1% of Ar is good. It is in a book Weston: Cold cathode glow discharge tubes. The higher the pressure is, the lower is velocity of the particles bombarding the electrodes, so the lifetime is higher. This is at least what I read. But the higher pressure also means higher breakdown voltage, so a compromise is necessary. The main thing that influences the lifetime is a presence of the mercury vapours inside (5.000 vs 200.000 hours), I found in one old patent that the amount of mercury is not critical.. Ron Soyland discovered one z566m (or zm1040?) with intact mercury capsule - they were not able to crack it during manufacturing. We counted the volume and found that there was 2.5mg of mercury, I would start at that amount.. anyway, thanks for info that mercury doesnt affect breakdown voltage.. I will have to experiment with mixtures.. Dalibor > > 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. > 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. -- Dalibor Farny http://dalibor.farny.cz -- 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/CA%2BnkT5o%3DRjgNSauG5N-9%3Da6Z50jCX%3DdAfAhmmgKSeCE_%3DytB0g%40mail.gmail.com. For more options, visit https://groups.google.com/groups/opt_out.
