I have an edwards e2m1 that I bought used for $200 which theoretically can reach .38 microns.
Its pumping speed however is slow and my rubber stoppers are not helping. My thermocouple gauge burned out unfortunately so I can't measure my current vacuum but I would not be surprised if I was achieving 5 microns or lower after extended pumping. A diffusion pump is not necessary in my opinion for experimenting, but probably is needed if you want to make a tube that will last for decades. Bombarding is an issue I have not solved, I currently just heat the tube with the torch for a while pumping to remove impurities and call it good. This leaves the electrodes unprocessed however and will lead to a shorter life. Simplifier and myself have both also both made functional Triodes using nothing more than a rotary vane pump, and he was able to achieve below 5 microns with his generic Chinese pump. Here is a link to Simplifier making a helium discharge tube using only a cheap rotary vane pump https://simplifier.neocities.org/discharge.html And his Homepage https://simplifier.neocities.org/index.html He has a whole list of vacuum and glass related projects and does them in the simplest way possible. On Sunday, October 24, 2021 at 7:03:38 PM UTC-7 gregebert wrote: > Did you need to use a diffusion pump to get below 10 microns ? Years ago I > researched doing neon tubes, but got discouraged by the high-cost of the > vacuum equipment and the dangers of bombarding. > > On Sunday, October 24, 2021 at 11:32:33 AM UTC-7 Chuck wrote: > >> I distinctly remember some of Dalibor's first tubes from mnay years ago >> when he first started experimenting. >> >> He made one that looked a lot like this one. Nice Work! >> >> Chuck >> >> >> >> >> ---- Original Message ---- >> From: "joshua dejaen" <[email protected]> >> Sent: 10/24/2021 2:36:14 AM >> To: "neonixie-l" <[email protected]> >> Subject: Re: [neonixie-l] Re: Homemade Purple Nixie Tube >> >> Thanks for all the comments, sorry I could not reply sooner. >> >> I have added mercury to glow tubes in the past but I have not wanted to >> contaminate my new pump. >> >> I could do it on my old pump but it is not able to pump below 1 torr and >> the tube would be left with impurities. >> >> My electrodes consist of copper welded to tungsten with a nickel buffer >> and then the tungsten welded to nickel wire that forms the digits inside >> the tube. >> >> The tungsten forms the actual seal to the pyrex glass and the copper >> provides a nice external lead. >> >> I heat up the tube with the torch while pumping for about a minute and >> let it pump under high(ish) vacuum (5-10 microns) for 30 min. >> >> I then open the bleed valve and adjust the pressure until the glow looks >> good and seal it off. >> >> I also have made Triodes in the past and those require about 15 min >> heating with the torch on the pump along with an hour of pumping. >> >> >> >> >> >> >> >> >> >> >> On Wednesday, October 20, 2021 at 12:49:28 PM UTC-7 [email protected] >> wrote: >> >>> I don't recall for certain if it was NeonJohn or another guy, or even >>> what group it was in. Could've been the old geigercounterenthusiasts group >>> on yahoo. This was some time ago, when we were laughing about the insane >>> overreaction to breakage of CFLs in school classrooms. I've never tried >>> opening a tube in a controlled fashion myself, but have seen tiny droplets >>> in broken ones, usually near the ends of the tube. >>> >>> Been playing with glass laser tubes a little the last week. Found that >>> Gammex patient positioners used both red and green HeNe before diodes took >>> over. Got one that won't lase though the plasma tube is a nice bright >>> pink. It hisses or buzzes continuously but no beam output. The PS is good >>> as it lit up a couple of similar size d tubes last night when I tried. I >>> need to completely remove it and try sighting through the bore. It's >>> possible it's leaking and coming up in pressure slowly and is now dead. I >>> was looking at the metal evac/fill tube where it's crimped off and >>> wondering about the possibilities of re-gassing... I have a couple of >>> those metal tube ends with some defunct old tubes I got from Laser Sam a >>> couple years back for experimenting. More interests, less time... >>> >>> >>> On Wed, Oct 20, 2021 at 2:37 PM Mac Doktor <[email protected]> wrote: >>> >>>> >>>> On Oct 20, 2021, at 2:59 PM, Nick Andrews <[email protected]> wrote: >>>> >>>> A guy built a device to try and capture the mercury, thinking he could >>>> recover and build up a small supply. He found that he never could get any >>>> significant quantity from the tubes. >>>> >>>> Did he condense the vapor first? >>>> >>>> >>>> Terry Bowman, KA4HJH >>>> "The Mac Doctor" >>>> >>>> https://www.astarcloseup.com >>>> >>>> “...the book said something astonishing, a very big thought. The stars, >>>> it said, were suns but very far away. The Sun was a star but close >>>> up.”—Carl Sagan, "The Backbone Of Night", *Cosmos*, 1980 >>>> >>>> >>>> >>>> >>> -- >>> >>> >>>> 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 [email protected]. >>> >>> To view this discussion on the web, visit >>>> https://groups.google.com/d/msgid/neonixie-l/4D0670A0-1C14-4185-8491-4629E387CD7C%40gmail.com >>>> >>>> <https://groups.google.com/d/msgid/neonixie-l/4D0670A0-1C14-4185-8491-4629E387CD7C%40gmail.com?utm_medium=email&utm_source=footer> >>>> . >>> >>> -- >> 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 [email protected]. >> >> To view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/17081a57-50be-4398-85ba-fc7572f0e209n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/neonixie-l/17081a57-50be-4398-85ba-fc7572f0e209n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- 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 [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/15ae8936-7bdb-40e9-95d3-12833dabb3a5n%40googlegroups.com.
