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.
I found this circuit in a 1976 magazine, but it can still be easily assembled, as all components are...
This circuit was found in a 1964 Electronic Design. The circuit can be implemented with equivalent...
This circuit from an 80's publication also features low input capacitance. FET can be a modern...