Hi Nick and Ira, and guus, and gregebert and Paul and anyone else I have missed,
Thanks for the replies. The light affecting the ionization was what puzzled me, but a couple of you explained that, and it makes sense. I have a way to test the tube on the bench, so maybe I can bring it back that way. I used the word "gassy" because that was the term we used working with big ion lasers (40+ years ago). I don't mean a leak, because any leak should be fatal. The laser tubes used getters that we heated with RF induction heaters to evaporate barium. The barium would trap any leftover impurities, and this was the last step in tube manufacturing. As the tube ran, material would sputter off of the cathode, and maybe other parts (there was ionized Ar and/or Kr inside of the tube, it was hot!). This would trap small amounts of gas. The getter material also continued to find impurities to remove. All of this would slightly lower the tube's pressure. The laser had an automatic gas filling system to keep the tube's pressure within a very narrow range, because a small deviation in the tube's pressure would greatly affect the laser's power output. If a tube that had been running long enough to have had some gas added was then left unused for a long time, some of the trapped gas could escape as it sat. This increased the tube's pressure very slightly - getting "gassy" - and that would affect the laser's output power. Running it for a while could cause it to again trap some gas, usually lowering the pressure enough to recover its original power output. That was how it was explained to me buy much smarter people, and it made sense. Over the years, some NIXIE tubes that I've had in storage have shown weak ionization. Running them for a while has cleaned some of them up, so when I have had a weak, but working NIXIE, I assumed that it is the same issue that I saw with the lasers many years ago. Maybe I'm wrong. Thanks again for the help. Jim -- 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/3f718cad-3f6c-02e5-6a23-af7f77463f14%40earthlink.net.
