This circuit is from 1980s documentation. The maximum operating frequency is 3.5 MHz. The current of the LED can be from 0 to 100 mA. The integrated circuits used are from that time.
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...