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 is the receiver for the previous circuit, also found in 90s Radio Electronics. The circuit...
This circuit from a 1978 American publication is used on vintage vehicles that still have contact...
This circuit was suggested by Popular Elecronics from the 90's. The circuit has high input...