Crystal oscillator with the 42 tube (T436E)

In the figure we have a crystal oscillator with a 42 tube. The circuit is from a 1935 Radio Handbook. The high voltage source is not provided.

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...