Radio Broadcast Service

Radio is an abbreviated form of radiotelegraph and radiotelephone. The word radio means radiation for wireless transmission. At first, communication was by radiotelegraph, using short dots and longer dashes in the Morse code. Now radiotelephone is used more for voice and music programs for entertainment. This application can be considered as communications electronics, which includes television. Practically all radio and television receivers are now solid-state, with transistors and integrated circuits instead of vacuum-tube amplifiers. See figure for a comparison of the old and the new in radio.

The transmission distance for wireless communication can be less than a mile or as much as 5000 miles, depending on the type of service, there are many different uses, such as radio broadcasting of voice and music, television broadcasting, amateur radio, and citizen's band (CB) radio. In addition, radio communication is used for specific services, such as police radio. Finally, radio navigation for ships and planes is another important application.

All radio services in the United States are regulated by the Federal Communication Commission (FCC). The FCC assigns the RF carrier frequencies for transmission and monitors use of the airwaves.