This circuit was found in a Motorola documentation from 1975. Modern equivalent transistors such as the BF245 can be used. The circuit is powered by 9 V voltage from cells or batteries.
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...