If they fail that quickly and the damage is concentrated in the center then it sounds like it could be also be ion damage to the phosphor as opposed to an issue with the phosphor itself. I'm not sure how good the vacuum is on some soviet tubes in general (I suspect it varied from factory to factory if not day to day) and most electrostatic CRT's of this era don't seem to have an an aluminium layer or an ion trap to protect the phosphor.
On Wednesday, June 3, 2015 at 6:46:45 PM UTC+1, petehand wrote: > > I was "shishlakji" on the old group, it's the same clock. Here is the > schematic. The M62354 DAC may need a little explanation. It's a voltage > output serial input DAC. The voltage reference is floating - does not need > to be ground at one end - this is unusual in DACs. Here the reference is > the voltage across diode D7. I jacked it up off ground for proper biasing > of the long tail pairs, but I ended up giving them a negative supply, so > any old DAC would do now. I have no idea where you could get a M62354 today > -I just happened to have some in my junk box. > > The 3LO1 tube life is definitely a phosphor problem. The phosphor layer is > so thin it's practically transparent and the brightness fades from the > center, where the beam traces over it most frequently. Towards the end of > life the center doesn't glow and only the tips of the hands are visible. I > don't know what such a short life tube could have been used for - perhaps > an instrument on a weapon when they expected the next war to be over in 24 > hours. > > -- 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/9cc90220-c884-4090-9fa2-1ca8dd6b9733%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
