Nixie Tubes!April 12, 2009 4:11 pm Cleverness
Recently I purchased a number of nixie tubes from the local electronics flea market:
A few of them caught my eye. This Burroughs B-5448 one was most likely used in a calculator or possibly a meter to indicate plus and minus as well as the overload condition.
And this National NL-989 was used for indicating the unit or mode of a multimeter. There are two “partitions” in this nixie tube: one contains the symbols “A”, “M”, and “K”, while the other contains “C”, “V”, and “Ω”. The multimeter would have used this to indicate “AC”, “MV”, “KV”, “MΩ”, “KΩ”, and so on.
Notice how the glow is a different color in each tube? My camera did an excellent job of reproducing the correct color, so what you see is very close to what the ionized gas actually looks like. The National tube appears to contain mostly neon, while the Burroughs shows light blue “fringing”, indicating the presence of mercury, which was used to increase the lifespan of the tube.