Hi All, Thanks for the replies, I'll try burning in the tubes as suggested.
As an aside, I read (somewhere on the internet that I can't find) that it is good practise to keep nixie tube anodes at ~90V when the tube is not lit? Is this correct, and is it worth doing for hobby clocks? Cheers, James On Jul 5, 9:25 pm, threeneurons <[email protected]> wrote: > > > I have acquired some Burroughs B6844A tubes, but I'm > > > having trouble getting them to light properly. > > > > Are my tubes dead, or is there a hope for them? > > > I bought a bunch of those tubes ... They exhibited the > > symptoms you described. > > > I'd recommend trying some different tubes. > > > David Forbes, Tucson AZ > > Given that nixie tubes are no longer made, I'd try to resolve the > problem, before turning them into "non-operating museum pieces", or BB- > gun targets. > > Light up a single numeral, with the offending 'glowing lead', and keep > it lit for a couple of days. Do it at the rated or maybe twice the > rated current (2-5mA). See if the 'lead-in' wire stops glowing within > that time frame. If it does, go to the next offending digit, and > repeat until the whole tube is cleared. It still might be a 'sub-set' > of cathode poisoning. If the tube still has problems, buy some BBs. > > Most of the time tubes can be salvaged, but on occasion, some are just > past redemption. I have a dekatron like that. It would not count > properly within the specified operating current range (300uA - 600uA). > Its a Sylvania 6476A. These tubes can usually be 'fixed' by running > them at 2mA for a couple of hours. At 2mA it does count reliably. But > once, its brought back down to a lower current, it stalls. I've run > that thing for a day (@2mA) then bring it down, then a week, a > month ... and so on. It still won't run in the normal range. Its been > running now, 24-7, for the last two years, at 2mA, and it still won't > behave at lower currents. > > Its running in a simple 'pendulum' circuit that's clocked at 10Hz. At > this frequency it'll probably run for several more years. At this > elevated current, it probably won't count at anywhere near the > advertised rate of 4KHz. Fortunately, it won't have to. > > So give it a shot. Either way. -- 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]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
