> My understanding is that the tube cathodes get damaged, when the tube > is in 'cut-off' over an long period of time. Its called cathode > interface resistance, which goes up under these conditions, Also > referred to as sleeping sickness, but not the same as with nixies.
Correct. > The tube makers found a less expensive > way to coat the oxide, with tubes that are susceptible to this > problem. Premium tubes, and 'computer' tubes like the 5963, have a > more secure oxide coating method. Not exactly. The tube makers had found that adding a little silicon to the (nickel) cathode mix made the oxide coating "activate" faster. Unfortunately, it also leads to the cathode being susceptible to the cathode interface problem if operated in cut-off too long (which wasn't common until tubes were used in digital computers). So the manufacturers would make tubes without the extra silicon in the mix for computer use. These tubes took longer to activate (and were thus more expensive to produce) becaus of this. > So it might be okay to use > the non-computer types, for the seconds and minutes. Reserve the 5963s > for the hours. This makes sense, unless you happen to find a stash of cheap 5963s. Since "linearity" was not part of the spec, I imagine that some of the computer tubes sound fairly awful. > Again, getting back to cathode poisoning, all cold cathode gas > discharge tubes, can suffer from it, in addition to nixies. I don't think so - the cold cathode tubes have a different type of cathode and coating, and don't operate at high temperature (hence "cold"). What nixies and the like suffer from is cathode poisoning - a different mechanism entirely. - John -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
