Nice pictures Mike! I'd agree with what you're representing here (esp the non-linearity at the top end), with one additional comment - this won't necessarily apply to tubes that have been sat unused in storage for a few decades. Some IN-9 seem to suffer from a sleeping sickness / cathode poisoning / whatever that can mean that even at 12mA you initially only get about 50% glow coverage as the OP describes. Reconditioning these so they operate smoothly over the full length under the intended operating conditions is possible, but it's a bit hit and miss. Back when I made this <https://www.youtube.com/watch?v=mQ1567EFCY0> I was having to chuck away a reasonable proportion of tubes that never made the grade even after extensive work.
As a starting point Mateusz, I suggest you tweak your circuit to allow you to put up to 25mA through the tubes. Even on heavily poisoned IN-9, that should clear out the crud and allow the glow to reach the top of the tube. But don't leave them unsupervised or keep them for long in this state - the tubes get hot and prolonged over-current is not going to help a long operating life! Interestingly, IN-13 don't seem to suffer the problem anywhere near so much. Jon. -- 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 post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/a6550c65-f310-4f4f-8e5b-424bd546d540%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
