I think that it's a mechanical issue. Any electrical issue that over-drove the cathodes would be visually apparent during operation -- especially at levels that could destroy cathodes in a matter of days or weeks.
Terry On Wednesday, August 17, 2016 at 9:56:44 AM UTC-5, Nick wrote: > > I'm with the others - there is something about this slot which > differentiates it from the others. > > Either it's a mechanical issue with the socket stressing the pins to the > extent the tube eventually becomes leaky.... > > ...or it's to do with the anode driver (the cathodes share the same drive > across all tubes) - either the anode resistor has failed in some way (or > isn't the correct value) or the opto-coupler is leaky/faulty (but I'm not > sure how that would cause premature tube failure), Vceo for a PC817 is 80V, > which should be OK, but this one may have failed - they are really cheap, > so maybe change it anyway :) > > Check the values of R11-R16. > > Have you tried the "faulty" tube in a known-good position in the clock? > Are you certain the tube has failed, not the surrounding circuitry cooking > slowly over time, then failing, then you turn the clock off to replace the > tube so it all cools down and the cycle repeats? > > Cheers > > Nick > > . > -- 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/3084282c-d4c3-483f-97f5-eb3d3e961f31%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
