I spent quite a bit of time with IN9 and IN13 making my one digit 7 segment clock (http://youtu.be/mQ1567EFCY0). Someone was also asking about them over on tubeclockdb.com, and this is how I summarised my experience there: *My recollection is that a batch of neon IN-9 tubes would generally divide into thirds when I was selecting tubes for the clock. One third would be A grade tubes - pretty homogeneous in performance; one third would be Grade B stuff - definitely functional, but with little hiccups, sticky points or perhaps incomplete removal of poisoning - quite usable, but not good for the clock where you want all the segments to track each other reasonably. The final third of tubes had gross issues and I chucked them. Argon IN-9 were worse than neon (fewer grade A), and the IN-13 were almost all grade A with very little cathode poisoning.* The para above refers to selection of tubes after a burning in process at around 2x full scale current to remove cathode poisoning which is universal on these tubes. So you see, even after pretty extensive clean-up, there's still a high attrition rate. Interesting you say that you have argon-filled tubes with a white top - all the argon ones I ever had came with purple tops. To Tim's point about what you feed them, I only ever worked with clean DC from a SMPSU, and that was fine on the good tubes. I'd be more inclined to blame the tubes - IN-9 are quite sensitive to rate of change of current. If you want to optimise your chances of keeping the glow in the 'proper' place, then you need to limit dI/dt, which may prove somewhat difficult for your VU application if the signal is swinging around on some ahem, banging music. IN-13 would likely give you better stability, though they're not as fun (too dim, orange only). Jon.
On Saturday, January 5, 2013 3:15:13 PM UTC, Tim wrote: > > > That is very interesting that you are not using a SMPS and still having > the trouble. I have never tried the tubes with a full bridge only a half, > I wonder if the difference between 50Hz and 100Hz makes any difference, I > cant see why it would. > > You say you have a large reservoir cap, effectively giving you smooth DC. > I dont think these tubes like smooth DC hence the SMPS being trouble. Try > removing the cap and see what happens. > > Hope this helps, > > Tim > > > > On Saturday, 5 January 2013 14:30:38 UTC, Alex wrote: >> >> 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/-/3HHJY0k4htIJ. For more options, visit https://groups.google.com/groups/opt_out.
