Interesting INS-1 behavior...

[Ben W]

So the INS-1 indicator neons are very fickle, anyone who has used them knows they tend to flicker. Usually you have to switch them out until you find a stable pair. I installed new INS-1's inside my clock recently, and one of them showed very odd behavior, the neon glow seems to be precessing in a circular pattern inside the unit like a decatron.

obviously I'm very interested to know what is promoting this behavior! Anyone have any ideas? the clock is multiplexed, maybe that has something to do with it, but the colons are as I understand driven directly from the HV power.

[Dekatron42]

Here's a site that explains the phenomena: http://www.g3ynh.info/disch_tube/lamp/flame_neon.html

/Martin

[Luka C]

the clock that I have built uses four INS-1 tubes, first few times when the clock was running for half a day (testing purposes) the INS-1 did not flicker. But after the clock was left to run for a few days, pretty much all of them started to flicker at some point. But..what is important is that now, half a year later, the clock is still running and all the flickering on INS-1 tubes has stopped, almost though if it was some sort of a burn-in period for them. I drive them with direct DC and within the datasheet specs, all the tubes are NOS.