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.
This circuit uses components that are no longer easily found. The circuit is from a 1988...
Suitable for battery powered microcontrolled applications this Texas Instruments circuit from its...
June 2016 - It can be purchased from Mouser Electronics the new triacs Z04 for 4 A from...