This circuit was found in a 1970 US publication. Transistors are still common and the circuit can be used as a PWM shield or pulse transmission modulator.
We present a commercial circuit for a small amplifier (CF-401) sold in Japan in the 1960s. The...
In the figure we have the circuit of a bistable using two relays. We found this circuit in an...
Found in American documentation from the 90's, this circuit oscillates up to 150 MHz. The...