The circuit is from the 1977 National Semiconductor Audio Handbook. The bass and treble control is Baxandall type. The integrated circuit used is not common today.
This antenna for the frequencies 146 or 440 MHz was found in a magazine 73 for Amateur Radio of...
This circuit produces 1 kHz square signals using the CMOS IC 4070. The frequency is given by the...
Found in a 90s PE Hobbyst Handbook, this circuit mimics the sound of a space gun. The components...