Glowing mercury thyratrons: inside a 1940s Teletype switching power supply
http://www.righto.com/2018/09/glowing-mercury-thyratrons-inside-1940s.html [www.righto.com]
2018-09-07 23:32
We recently started restoring a Teletype Model 19, a Navy communication system introduced in the 1940s. This Teletype was powered by a bulky DC power supply called the “REC-30 rectifier”. The power supply uses special mercury-vapor thyratron tubes, which give off an eerie blue glow in operation, as you can see below.