This alarm oscillator was found in the December 1974 issue of Radio Electronics magazine. The power transistor must be equipped with a good heat sink. The Frequency basically is given by C1.
This fuzz distortion circuit was found in old RCA documentation. Equivalent transistors may be...
This circuit for the two-meter band of radio amateurs was found in 1980s documentation....
This circuit was obtained from an American publication of the 80's. The integrated circuit is of the...