Cheers for the replies guys, I suspect that with a bit of running in most of the tubes I have labeled "Slight poisoning" will come right... It is strange that your purple topped tubes are distinctly different from white topped, maybe I got lucky with my white topped but I defiantly prefer the true neon IN-9 glow...
My test rig could not be better for the tubes: UK Mains -> Isolating TX -> Variac -> Full Bridge -> Large reservoir cap -> 25K W/W Pot -> 1K 10W Fixed R -> mA Meter -> Tube. Defiantly no switching noise! I will leave a few of the worst offenders on burn in for a half day and see if they wake up a bit better.... - Alex On Saturday, 5 January 2013 11:46:34 UTC, Tim wrote: > > > Hi Alex, > > First things first, I love IN-9 tubes and am in the process of making an > audio spectrum analyser with them. I have both the orange and violet > versions. My violet ones having the purple top and do illuminate with a > very purple glow :o) These tubes are trouble and very hard to make them > consistently illuminate from the bottom as they do not have the extra > electrode the IN-13s have. But there is a way! > > I would be very surprised if your problem is being caused by cathode > poisoning, it is more likely to be because of the power supply you are > using. These tubes do not like being run off nice clean DC from a SMPS. > One must consider that when these tube were first being used (decades > before I was alive) SMPS were not used to any extent (if at all?). They > were powering the tubes from good old half wave rectified DC. I personally > power the tubes from a mains isolation transformer (I think it came out of > a bathroom shaver socket) and a single 1N4007 rectifier diode. I don't > think I have ever had one misbehave being powered in this way. Give it a > go and see if this solves your problems. > > Don't forget that the IN-9 are very power hungry compared with that of the > IN-13. > > Hope this helps, > > Tim > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msg/neonixie-l/-/QK727elqXXkJ. For more options, visit https://groups.google.com/groups/opt_out.
