Are those Nixie clocks I spy there?
Absolutely. Nixies are my gateway drug into embedded design. The main stash is well hidden however
These are gorgeous panaplex tubes!
What size of the segments are they? 50mm?
The tubes in the foreground are Burroughs B7971s. They are some of the larger nixies out there. 15 segment (14 + bottom arrow). Digit height is 63.5mm.
The tubes in the backround are the middle child of the Burroughs alphanumeric nixie family, the 8971s. They are much rarer than the larger 7971 tube. Smaller overall, with a digit height of 36.5mm.
Its an addiction!
If anyone is seriously interested in nixie tubes, related driving circuits/clock designs, there is a big google group that I would recommend checking out: neonixie-l
https://groups.google.com/g/neonixie-l?pli=1. Tons of nixie tube knowledge, trading/selling, and generally a great place to indulge with others in the hobby. I've been on there for a few years, and there are some old timers that go way back to the original yahoo group also by the same name.