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/5236ede3-ce15-428e-8b3b-4649a83ffbc0n%40googlegroups.com.
