Minutiae - 5870 tube lead diameters

[David Forbes]

I have handled a lot of 5870 tubes, making Nixie watches. About 4,000 so
far.

I have noticed that there are different diameters of lead wires on these
tubes. (The lead wires are cast into the glass header, and the cathodes
are spot-welded to them.) The different wires tend to be mixed together
in a batch of tubes, rather than one batch with heavy wire and another
with thin wire.

The thickest leads are 0.40 mm diameter, while the typical ones are 0.35
or 0.38mm. I just encountered one today with 0.29mm leads.

Do you suppose the factory had different header-making machines fed by
whatever wire they had lying around? I would have expected this
parameter to be controlled a bit better, but I don't run a tube factory.

Thoughts?

--
David Forbes, Tucson AZ

[Jonathan F.]

Do they have date codes on it? Maybe at some times they a specific wire was not available.

Maybe they were made at different factories/machinea
Or it wasnt a parameter that was critical for the manufacturer. Like that little glass stem on some tubes.

[Instrument Resources of America]

Or maybe the wire manufacturer had some pretty sloppy tolerances!!! Ira.

[Charles MacDonald]

On 16-05-04 02:09 PM, David Forbes wrote:
> I have handled a lot of 5870 tubes, making Nixie watches. About 4,000 so
> far.
>
> I have noticed that there are different diameters of lead wires on these
> tubes. (The lead wires are cast into the glass header, and the cathodes
> are spot-welded to them.)

> The thickest leads are 0.40 mm diameter, while the typical ones are 0.35
> or 0.38mm. I just encountered one today with 0.29mm leads.

quick look for a data sheet shows they are specified as 0.014 to 0.017
Typical diameter. that gives .35 to .43 in mm if I did the conversion
right.


--
Charles MacDonald Stittsville Ontario
cm...@zeusprune.ca Just Beyond the Fringe
No Microsoft Products were used in sending this e-mail.