None of my 7971's has aged enough for the segments to get flaky; my clock went into operation in 2017. Knocking on wood.....
I've seen 2 types of incomplete segment/numeral illumination. On my IN-18's, it's cathode poisoning for the months-digit and that clears-up within a few days of the new month. Obviously my depoisoning algorithm isn't perfect, yet oddly enough the years digits dont show any poisoning so there is some factor here with the tube. BTW, it's a 14-tube clock using MM-DD-YYYY HH:MM:SS format. The other incomplete illumination appears to be end-of-life for the tube, because no amount of voltage or current has been able to fix the tube. You get what you pay for when you buy used nixies online; many are OK, some are not. On Monday, October 9, 2023 at 8:22:05 AM UTC-7 Rob B wrote: > When I was a kid [~50 yrs ago], I had several power strips with NE-2 > indicators, where the indicator starting flicker and then eventually > failed. I noticed that when sunlight hit the NE-2s, they lit more solidly: > flickering converted to solid, and off converted to flickering. I always > assumed it was the energy from the sun's photons that was adding just > enough joules to the equation to push failing bulbs back over their > ionization threshold. Same effect, probably? > > ...R > > On Saturday, October 7, 2023 at 12:26:27 PM UTC-5 Jim KO5V wrote: > >> I have a B7971 that doesn't want to light up - the ends of some segments >> will glow, but none will illuminate along their entire length. I have had >> tubes in the past that were probably a bit gassy, and they cleaned up after >> running for a few minutes to a few hours. >> >> So, I put it into the "10 second" position of my Mod 6 clock, and ran it >> over night with no improvement. However after I had been up an hour or so, >> I noticed that the tube's segments were lighting up along about 3/4 of >> their lengths, and also that the low morning sun was shining on the clock. >> This state lasted for as long as the sunlight was on the tube - sometime >> after light moved off of the clock, the tube went back to it's wounded >> state. >> >> This morning I watched as the sunlight moved toward the clock, and as >> soon as the light hit the clock, the tube immediately recovered, and >> performed like it did yesterday. However, that state lasted for about 3-1/2 >> hours after the sunlight moved away. I then shined a flashlight on the >> tube, and it recovered as long as the light was there. >> >> I guess this is some kind of photo-voltaic effect. I have a bit of >> education in basic physics (for engineering), and this baffles me - but >> it's cool! >> >> I have a reading lamp that puts out a full spectrum, so I will put that >> on the clock today and see what happens. I may also set up a test to run >> the tube at a bit higher voltage (180-ish V). It may never recover >> completely, but I think this is a fun exercise. >> >> Anyway, and ideas are welcome. I may not be able to save the tube, but I >> might actually learn something. Thanks. 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/8b034b25-3a01-4793-bc84-52956882b050n%40googlegroups.com.
