Optical shield (CB20698E)

This circuit was found in American documentation from the 90s. The coupler is the type that uses a photo-Darlington.

Drain dip oscillator (CB22029E)
This drain dip oscillator was found in an old English documentation. The JFET can be of any type...
SCS 5 kHz stages (CB9068E)
This SCS counter circuit was found in a 1964 General Electric documentation. The circuit has a...
MW Commercial Radio EB-180 (CB18352E)
This is the circuit of a commercial radio from the 60s, sold in Japan. The circuit shows the...