Next-step is to bench-test one of your tubes that has failed to see if it can be depoisoned, or determine if it's truly dead. Do you have a supply that goes up to around 200V ?
What is the multiplexing frequency ? Years ago, my neighbor who was an EE told me about an ultrasonic cleaner he was developing back in the 1960's. It worked great, but after a few months it would fail. They found out that the bondwires on the transistor reached mechanical resonance at the same frequency as the ultrasonic cleaner and failed from mechanical fatigue. They literally had to have the transistor manufacturer create a new transistor with different mechanical properties. End of problem. Could the multiplexing frequency be causing micro-vibrations inside the tube, leading to glass-seal leaks ? Who knows. One thing I've learned is never to rule out ridiculous-sounding causes of failure, because they do happen. -- 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/0b8abdc0-75e1-478b-88d2-973b1a78a6bf%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
