Voltage amplifier with the 37 tube (T392E)

Found in a modern design book with tubes, this stage with the triode 37 has a plate current of 3.7 mA.

High Gain Amplifier (CB4250E)
This high gain small signal amplifier circuit was found in an old publication on transistors....
Third Brake Light (CB4783E)
This circuit was found in a Popular Electronics of the 90s. It operates a third brake light that...
APR345 Rectification Synchro Controller (COM114E)
September 2016 - It can be purchased from Mouser Electronics the new rectification controllers...