This circuit with germanium transistors was found in a publication by Gernsback from 1960. The circuit is low power, a few tens of milliwatts.
This high-performance circuit was found in the 1982 SGS Linear Integrated Circuits Manual. The...
Found in a 90s Electronics Engineering, this circuit makes use of components of the time. The...
Found in a magazine 73 for radio amateurs, this circuit has two settings, one for the interval and the...