This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit equivalents although the indicated types can still be found with some ease.
We found this circuit in a 1971 documentation. The circuit can be assembled with more modern...
The frequency of this oscillator depends on R and C (see math section for electronics). The...
This amplitude modulated (AM) oscillator was found in an Electronic Design from 1965. The circuit...