Nixie Tube Age Matter?

[Dman777]

Hi, 

If a Nixie tube is unused, should the age of it matter(the year when it was manufactured) in determining the lifespan of it? For instance, would a Nixie 5660 that is made in 1985 versus a IN 18 made in 1991? 

Thanks,

-Darin

[David Forbes]

It would matter if the manufacturing process changed.


--
David Forbes, Tucson AZ

[greg...@hotmail.com]

You are talking about different manufacturers, and also different ages. Best thing I can recommend is to ask for data from members in this group.

The big clock I made last year used fifteen IN-1 tubes manufactured in the 1980's, and I had tube failures every few days.

I replaced them with Burroughs 6091 tubes manufactured 1963 & 1967, and there have been zero failures or degradation after 1 year.

So, even though the IN-1's were about 20 years younger, they were definitely inferior. One would expect that newer manufacturing processes would produce more reliable tubes, but that's not the case here.

Even with the same manufacturer, different tubes will have different lifespans. I have several Burroughs 5031 tubes that appear to have cathode-poisoning because some numerals are not fully illuminated. I cant read many date-codes, but they appear to be ~1963. I have tried and failed to rejuvenate them with higher current. I also have a several dozen Burroughs 5092 tubes, many of which were made in 1963, yet none of them show any signs of degradation. It appears that Burroughs made a substantial improvement with the 5092, though I have not been able to find out what they did. Perhaps it was the addition of mercury, but that is just a guess.

[Charles MacDonald]

On 14-06-05 11:13 AM, David Forbes wrote:

> It would matter if the manufacturing process changed.
>

Some Nixies and other gas tubes did use a radioactive gas to make for
easier stating of the glow. (or some solid material inside the tube)

if that happened to have a half life relatively shorter than the Age of
the tube, it may make the tube require a higher start voltage to fire.
This is more likely to be a problem in decatrons and the like.



--
Charles MacDonald Stittsville Ontario
cm...@zeusprune.ca Just Beyond the Fringe
http://Charles.MacDonald.org/tubes
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