We found this circuit in a 70s RCA manual. The circuit uses an LDR by directly driving a sensitive relay. Resistor R1 is 5.6 ohms and R2 is 25k. The pot is 10k of wire.
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...