Shortwave radio is radio transmission using radio frequencies in the shortwave bands (SW). There is no official definition of the band range, but it always includes all of the high frequency band (HF), which extends from 3 to 30 MHz ; above the medium frequency band (MF), to the bottom of the VHF band.
Grundig Satellit 400 solid-state, digital shortwave receiver, c. 1986
Radio amateurs carried out the first shortwave transmissions over a long distance before those of Guglielmo Marconi.
National Panasonic R3000 analog shortwave radio receiver, c. 1965.
Portable shortwave receiver's digital display tuned to the 75–meter band
Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves. They are received by another antenna connected to a radio receiver. In addition to communication, radio is used for radar, radio navigation, remote control, remote sensing, and other applications.
An antenna farm hosting various radio antennas on Sandia Peak near Albuquerque, New Mexico, US
1100 W AM broadcasting transmitter
Mast radiator antenna of AM radio station
Panasonic AM radio from 1964
