I have about 12 6844A, all NOS, none of them work - they show the same symptoms that you described.
On Friday, December 11, 2020 at 1:45:30 AM UTC-5 gregebert wrote: > I have not been able to figure that out for years. You would think the > internal leads were coated with an insulator so they dont glow, or perhaps > they use a different metal with a higher workfunction than the actual > cathodes, so they would not glow in normal circumstances. But when the > cathodes are still visible, I dont understand why they have no glow. I > doubt they would be selectively plated with another metal, which completely > sputtered away, leaving them unable to glow. > > I have a bag of dead nixies, mostly 5031/6844, took 2 out, and microwaved > them for 2 seconds. Got a brilliant crimson glow. One of them shows some > cathodes working, so now I have to go back thru the bag to make sure I find > the totally dead ones, or at least the ones that have glowing only on the > bondwires, and nuke them in the microwave oven. I have other boxes for > dying nixies, and so-so nixies, so I'm really surprised anything in the > "body-bag" of dead ones actually glowed. Unless perhaps the zap from the > microwave oven did something to the internal metal. > > I have some more experimenting to do. > > On Thursday, December 10, 2020 at 4:57:40 PM UTC-8 Chuck wrote: > >> Burroughs 6844A is domed not flat. I also have some National >> Electronics NL-6844A tubes. Frankly, I have had much better >> >> luck with the National Electronics brand. This recently purchased batch >> of (8) Burroughs 6844A tubes is a bad batch. >> >> The boxes all are stamped MAR 4 1968. The tubes themselves are >> date-coded 6750 F20. In white letters stenciled on the glass: >> >> "Burroughs 6844A NIXIE". >> >> >> >> The test I did was that the anode got connected to +170 volts DC through >> a 15k resistor. Then the digit cathodes were selectively >> >> grounded to the negative side of that power supply. On all (8) of >> these Burroughs tubes, most of what is seen is an intense glow concentrated >> >> around the tiny internal wires which connect the digit cathodes of the >> stack, to the pins. These tiny wires pass closely to the outside of the >> >> Anode casing which surrounds the digit stack. The glow strikes in the >> wrong place. The glow is around the lead wires instead of being >> >> around the digits. I am very confident from the way these tubes were >> in those boxes, that only one of the batch had even ever been out of the >> box. >> >> >> >> So I am curious what causes the glowing lead wires. >> >> >> >> Chuck >> > -- 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/df3e7d5c-f568-4f9b-bde3-ac107aa0fff3n%40googlegroups.com.
