On my B7971 clocks, you can hear the tubes “sing” at the mux rate, and the “timbre” would change as the digits changed (the mux’ing also generated at lot of RFI). I mentioned this many years ago when I said that they had been running 24/7 for over 30 years (now 40) with zero tube failures. One other list member suggested that I might have been hearing the magnetostriction from the transformers in the SMPS, but I found this unlikely since I could isolate the sound to the tubes and because I had used linear power supplies.
BTW, is the “clanging” noticeably louder when multiple digits change simultaneously? (On my computer, the clanging in the video is not synchronized with the changing seconds digits). You might be able to reduce the noise by increasing the rise time of the current applied to the tubes. -- 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/78a20988-ba5e-409c-9819-2556c1951dcc%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
