This circuit was obtained from Dutch documentation from 1964. The components are of the time, but current equivalents such as BC548 to BC108 can be used.
Suggested by Siliconix in documentation from the 90's, this circuit supports current equivalent...
This circuit decodes a 1800 Hz tone used in communications. The circuit is from an American...
This circuit was obtained in 1981 documentation. It is an FM transmitter that can serve to emit...