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.
Found in an Electronic Design from the 90s, this circuit does not need sinks for its components. The...
The figure shows a way to apply gain control to the LM3600 OTA. The circuit is from a Radio...
This circuit was found in a 1968’s General Electric documentation. The circuit has a control range of...