Shortwave radio refers to a type of radio transmission that can travel long distances using short wavelengths. It allows people to listen to radio broadcasts from all around the world, even if they are located far away. Full definition
Bell Telephone Laboratories engineer Karl Guthe Jansky was only looking for ways to cut down on shortwave radio static when he found radio waves coming from outer space in 1932. (scientificamerican.com)
They have about the same power at all of the wavelengths down to the microwave wavelengths (shortwave radio wavelengths). (astronomynotes.com)
Though this image may appear innocuous, it depicts radio towers in Germany that some espionage agents believe are used to transmit top - secret information using coded messages over shortwave radio signals. (artspace.com)