Shortwave radio broadcasts between 3 and 30 MHz (3,000 kHz to 30,000 kHz), and signals can be heard across long distances. They were frequently used during World War II, usually transmitting coded messages. First introduced in the 1920s, shortwave broadcasts revolutionized the world of radio, making international broadcasting and international communication possible. Shortwave broadcasts work in conjuncture with the ionosphere... the...Continue Reading
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