NE-68 and NE-81 Neon bulbs?

[Dekatron42]

Hi All,

I have been trying to buy a bunch of NE-68 and NE-81 Neon bulbs to repair some Burroughs counting modules that I have where the bulbs have cracked and the gas has escaped, the cracks have happened since the modules had been stored poorly so the pins corroded. I haven't found any place yet that actually has them in stock, when I have tried to buy the ones supposedly in stock there were none to be had.

I've also been thinking about if it would be possible to use either a zener diode or TVS, one-way or two-way, to emulate the Neon bulb, does anyone have any experience with this?

The NE-68/NE-81s are used as voltage dropping elements in the tube circuit, have a look here: http://www.radiomuseum.org/forumdata/users/6435/articles/trochotron/100K_cntr.png where the NE-81 is used.

/Martin

[John Rehwinkel]

I have been trying to buy a bunch of NE-68 and NE-81 Neon bulbs to repair some Burroughs counting modules that I have where the bulbs have cracked and the gas has escaped, the cracks have happened since the modules had been stored poorly so the pins corroded. I haven't found any place yet that actually has them in stock, when I have tried to buy the ones supposedly in stock there were none to be had.

Don's Bulbs has 'em (I've worked with Don before, he's a decent guy).

http://www.donsbulbs.com/cgi-bin/r/b.pl/ne81~usa.html

I've also been thinking about if it would be possible to use either a zener diode or TVS, one-way or two-way, to emulate the Neon bulb, does anyone have any experience with this?

I'd think zeners would work.  It looks unidirectional, so I doubt you'd need two zeners.

- John