Madness wrote:
Thanks for the replies, everyone. I forgot to mention that my lot (about
30) is of vintage GE NE-51's, not the modern "NE-2 w/ plastic lens" variety.

Note that many neon bulbs had some sort of radioactive doping to get
them to fire at a lower votage.

I don't have any hard data, but I believe it was thorium up until the late
1940's when the US government decided that radioactive material needed
supervision.

It was found to be simpler to just add a small amount of radioactive
krypton gas to the neon. However the half life of the krypton gas is
about 10 years. So neon bulbs made in 1970 would have about 1/20th of
the krypton still radioactive, which is probably no longer able to
make a difference.

Speaking of radioactivity, if you are looking for an unusual project to
make from them, they can be used to make geiger counters.

I don't think they are very sensitive, but if you live in the US, the
red Fesita Ware department of any thrift shop would make it "go nuts".
:-)

Geoff.
--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379