Martin, you are right. I've checked the getter flash and it is gone. Only a white shadow left. So, sadly, the tube has sucked air and is cracked somewhere at the pins. Unfortunately, I don't have a plasma ball.
Dekatron42 schrieb am Sonntag, 4. Oktober 2020 um 01:20:23 UTC+2: > Have you got a Plasma ball to hold it to? If air has entered in you might > see a very faint blueish glow if you turn off the surrounding light. > > What does the getter flash look like, like a mirror or is it gone > completely, or has it gone white? > > I have seen a few Nixies where the Anode wire has come lose at a welding > spot, can you see if something similar has happened to your Nimo with any > of the wires or the Anode connection - if so you might smack it gently > against your palm to see if the wire reconnects enough for it to work again? > > /Martin > > On Saturday, 3 October 2020 23:35:35 UTC+2, jörg wrote: >> >> Hi Gregebert, yes, I've checked the tube several times. The cold >> resistance is about 2,1 ohm, which is identical to the other tubes. >> Just swapped the tube with a running one on the same driver board. Sadly, >> no function at all. Under a microscope, no crack is visible. >> >> I've made a short video to show the difference between a neon-nixie and a >> nimo crt-tube and a neodym magnet (very small one.) >> https://www.youtube.com/watch?v=JJytnrvTy3Q >> >> gregebert schrieb am Freitag, 2. Oktober 2020 um 19:25:40 UTC+2: >> >>> Jorg - Regarding the dead tube, have you compared the filament >>> resistance of the bad tube to the others ? >>> >>> NIMO tubes have 2 parallel filaments, so if one is open, the resistance >>> will be TWICE the value of a good tube. >>> I think the cold resistance is around 3 ohms. >>> >>> If 1 filament is out, you can still get 5 numerals to work. >>> >>> I would be surprised if both filaments are burned-out, unless someone >>> put way too much voltage on it, or the tube is cracked around the pins. >>> >>> If the filaments are OK, power-up the tube and make sure you get around >>> 180mA of current. >>> Then try varying the voltage between the filament and the logic driving >>> the grids. If a grid is about 6 V more positive than the filament, you >>> should get a numeral to turn on. >>> >>> On Thursday, October 1, 2020 at 1:44:20 PM UTC-7 jörg wrote: >>> >>>> Short update of my nimo project. >>>> I've got 5 tubes running. The sixt is unfortunately DOA. >>>> The tubes filaments are driven with three power supplies, with soft >>>> start IC (load switch). >>>> So the filament gets started very smooth. >>>> I've made some experiments with multiplexing the tubes. >>>> Which work nice, using the method described in the manual. The bias >>>> voltage is changed for every tube, that should be on/off. >>>> In the actual approch, I'm using direct driving the tubes via 74HC595 >>>> shift registers. Got a plenty of problems at the beginning. >>>> The power and signal lines for the 595 were messed with switching >>>> noise. Some caps did the trick. >>>> Really nice to view the working tubes. >>>> >>>> Video: https://www.youtube.com/watch?v=JbwfZhYhnlo >>>> >>>> jörg schrieb am Mittwoch, 15. Juli 2020 um 18:01:18 UTC+2: >>>> >>>>> I‘m using Eagle to layout. >>>>> It takes time for me to feel comfortable with it. >>>>> And Fusion360. >>>>> >>>>> -- 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 view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/c0b5b22a-bfdf-43b0-8e5a-4ad6e3d8f270n%40googlegroups.com.
