This transmitter uses a small loudespeaker (FTE) as microphone and can send the signals to distances up to 300 feet. The antenna is a piece of wire 50 to 120 cm long and T1 is a small output transformer such as the one found in small old transistor radios. The circuit can be powered from 6 to 9 V supplies andL1 is formed by 40 turns of 28 AWG wire on a ferrite core. All capacitors are ceramic types and CV is a small variable capacitor such as the ones found in AM transistor radios.
