This circuit was found on an 80's Ham Radio. The transistor admits equivalent. The circuit can generate 20 to 100 MHz signals operating at the fifth harmonic of the crystal.
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...