sale or trade- B7971 2.5" 17-segment nixies

  • zzf7a55434
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8 years 11 months ago #2348 by zzf7a55434
Replied by zzf7a55434 on topic Re: little glass bar
Thanks for the confirmation.

IIRC the only pure-neon tube about that size had a return electrode for each segment. as otherwise the strike voltage needed to ionize the neon would be insane- and the current would indeed eat the electrodes for lunch.

Mercury and the other trace gasses added [like Krypton] help the initial ion path form.

Adding the toxic elements after the tube is sealed to avoid worker exposure makes a lot of sense.

Bob McMains,
broken joat

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  • zzf7a55434
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  • ex-J.O.A.T, int. source of B-7971s + Other Odds
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7 years 9 months ago #3171 by zzf7a55434
I think someone answered this- called a 'giver'- it's what the mercury and whatever else was in so they could purge, fill & seal the tubes with pure neon, then use the heating element to melt them free after the touchy part was done. cheaper & safer.

I came up the for-sure last bits from my supplier.

a matched set of 4 'antenna' B7971's with white Burroughs print, hand-assembled [inferred- they wouldn't shift back from the printed circuit-on-mica, right?] nickle ribbon construction. and a used socket.

now I need to price 'em, the last I sold I got $150 for... I need to check the market..

Bob McMains,
broken joat

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4 months 2 days ago #11232 by galen1992
hello, are the last 4 b7971 sold?

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