[Test-Equipment] Nixie project

[J. Forster]

> IF the nixies require some ionizing radiation to help them fire, IR or
> visible light will probably not help. Those are a non-ionizing radations
> (not to be confused with radioactive radiations).

At a guess, I'd think that light of wavelength shorter then the Ne
emission line (higher energy) would trigger a Ne discharge, but that's a
guess.

> Ne lamps can be
> sensitive to light, however, and other effects as well but I've not
> researched the reasons. However, Ne gas should be able to fire (ionize)
> with sufficient applied voltage alone.

Likely so, but that will not help w/ the Nixie issue. If you apply enough
voltage, it may break down in other than the desired way.

> I suspect the improved nixie
> performance noted by the original poster is similar to observations about
> very-old-stock filament tubes that improve when put in use.

I'm not vconvinced of thet. Old vacuum tubes can become gassey, and the
gas will be scavanged by the getter with operation with filament and plate
applied, but I'm not aware of a comparable mechanism in Ne tubes.

The only effect I'm aware of is desorbtion of Ne or other filler gases
from the glass and metal surfaces with heating.


> The nixies I
> run in my HB freq counter do get warm over time; maybe that is sufficient
> to cause a getter action?

See above.

> When I was playing with He-Ne gas laser construction long ago no one ever
> hinted that any radioactives had to be inserted in the construction to
> make them work,

Laser supplies usually have a "kick start" provision, like a
Cockroft-Walton multiplier.

> so I wonder sometimes about the origins of the info that
> gas discharge tubes in general must have some form of radioactives to
> make them work.

The radioactive pre-ionization is to improve triggering stability.

> Perhaps some gases do (i.e., hard to ionize), or some
> manufacturing methods used that technique to achieve a particular
> performance effect?
>
> Wayne
> WB4OGM
>

Best,

-John

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