Nixies do have a lifetime (stored), but it expresses itself slowly. Mainly, loss of gas pressure, I see this effect most often in panaplex displays (which are actually glued together), and in russian tubes, which seem to have a poorer lead seal at the base. In every box of 50 russian tubes, I generally find one that is totally dead. US made tubes seem to fare better, but older types, like the 6844A are now at about 60 years old, and it is common to see low gas pressure in them. the symptom is increased voltage to strike, and sometimes poor digit coverage on the larger cathodes, or in the extreme case, nothing happens. I have often seen tubes 50 years old work perfectly, but equally, they also can be improved by cycling them through all the digits a few times. Old used tubes are more problematic, any unused digits often are poisoned, and have to be carefully restored. Like any "vacuum" tubes, their success is dependent on the quality of the glass seal, whether to hold in gas or vacuum. rough handling of the leads or shock are the primary failure mechanisms to break the seal.
We have built a test jig to run and cycle all the tubes along with a variable supply and series resistor that runs up to 300V. this allows us to find tubes with low gas, poisoned cathodes, base flash-over and other problems, plus it can be used to re-condition tubes and bring them back to optimal performance. I would suggest something like this if you intend to do a lot of nixie experimenting, as it allows you to really see the tubes work under different voltages and currents, and be sure the tubes are suitable before attempting a build. this is especially useful if the tubes solder in. all the best, walter (sphere research corp) On Wednesday, 20 July 2016 22:58:49 UTC-7, Steve Scorn wrote: > > Hi group, > > Does an unused NOS Nixie have a serviceable lifetime? I'm aware of cathode > poisoning etc when powered on, but if correctly stored, would a NOS Nixie > be just as good in 50 years as today? > > Thanks for the help. > > Steve > -- 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 post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/fec8d65c-bd44-46ac-97ee-9a0e0611786a%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
