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 circuit was found in the January 1995 Electronics Now magazine. Its configuration is valid for...
This circuit with transistors in parallel was found in a Radio Electronics of August 1952....
We find this simple circuit in an English publication called Electronic Circuit Design no. 3 of...