We find this circuit in an Electronic Design of the 90s. The used integrated circuit admits equivalents and next to the diagram are given the formulas for the calculation of the components used.
This receiver was found in a 1968 publication, but can be mounted with a BC548 and BC558 in place...
Found in 1965s General Electric documentation, this circuit is intended for the control of servos...
The integrated circuit used in this 90's circuit is not very common today. An equivalent...