Salvaged VFDs in Nixie-Like Clock

In between the Nixie tube era of the 50s and 60s and the advent of multi-digit vacuum fluorescent displays (VFDs) common in 80s and 90s consumer technology, there was a brief time in the early 70s where single-digit VFDs were commonplace. Superficially these devices look like Nixie tubes, but have a number of advantages to them including lower voltage, lower power requirements, and lower cost. [maurycyz] recently found a number of these salvaged from old calculators and used them to build a retr