This tone-modulated transmitter produces a tone with frequency depending on C4 and C5. Free transmission frequency is given by CV, a 2-20 pF trimmer. For the 20 to 40 MHz band L1 is formed by 8 turns of 22 or 24 AWG wire in a air core form with a diameter of 1 cm. The antenna is a telescopic type and range can be up to 100 m in open places. The circuit also operates in the FM range. In this case change L1 to 4 turns.