This 555 IC circuit was found in June 1984 Radio Electronics magazine. This circuit detects a change in the signal and can power a relay or other warning system.
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...