This circuit with germanium transistors is from 1960 and was found in Mullard's transistor application manual from 1960. The circuit can be adapted to use more modern transistors.
This is another of the Star Trek red alert circuit that you can find on this site. We took this...
Found in American documentation from the 1980s, this circuit is a basic signal rejection filter...
This circuit can be used in physics experiments, in ionization and in several other applications. The...