This physical line servo control uses components that are not currently common. The circuit is from an 80's documentation and is powered by a voltage according to the servo.
For the 7 to 10 MHz band L1 is formed by 3 turns of 22 to 28 AWG wire in a ferrite core 15 to 20...
This circuit show the performance of a GraetzBridge or Diode Bridge usedin full-wave rectifers....
This adjustable source was found in a 1979 documentation, but all components are still common...