||a radio with a built-in clock that can be set to turn the radio on at a given time.
|quasi-stellar radio source
||the study of the universe by observation and analysis of extraterrestrial radio waves.
||a stationary source of radio waves that emits a distinctive signal as a navigational aid for ships and aircraft.
||a navigational aid consisting of a radio receiver that determines the transmission direction of incoming radio waves.
||a galaxy that emits a large amount of radio energy.
||the portion of the electromagnetic spectrum consisting of radio waves, esp. those most frequently used in radio and television broadcasting, from ten kilohertz to 300 gigahertz.
||an organization equipped for broadcasting radio. [2 definitions]
||a concave reflector or array of reflectors designed to collect and focus extraterrestrial radio waves for analysis.
||an electromagnetic wave with a wavelength of between one millimeter and thirty thousand meters, or a frequency of between ten kilohertz and three hundred thousand megahertz.