Thanks for the info, it sounds like a slightly different use case, but a valid one. Given the age of the oldest tubes I have (early 70's) I can't imagine that multiplexing was the normal mode of operation, and direct drive was more likely. On the other hand, I find it hard to believe that these tubes would have had a 20+ year prouction run if they had been so terribly unreliable.
One thing that comes to mind is that perhaps the current was too high in direct mode. Do you have a sketch of the circuit? Perhaps a cycling of digits is particularly important for these tubes? Why should a bridge form from one cathode to the other? Was it the same digit pair each time? Is there perhaps a bias voltage that should be applied to undriven cathodes? I'd love to understand the failure mechanism better, and perhaps I'll manage to reproduce it when I have some sacrificial tubes. In the mean time, I'll report back if any of the 20 something IN-1s I have in action play up. Ian On Thursday, 14 May 2015 02:17:19 UTC+2, gregebert wrote: > > Perhaps your tubes were from a different manufacturer, and probably a > different manufacturing process. Since they are from 1984 to 1987, that's > even more likely. > > My IN-1 tubes are from the Anod plant, and have date code of 1992. Each > tube was displaying a single numeral 24/7, with no cycling, dimming, > multiplexing, etc. I had failures every few days. Each failure was a > micro-filament that developed between adjacent cathodes, causing an > electrical short between them. > > After switching to Burroughs tubes, I've had only 1 failure with 15 tubes > after 2 years. That failure appears to be a broken internal spot-weld. > -- 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/7df467a9-db54-40dd-b033-30a23e2d6dfc%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
