First radio program of voice and music broadcast in the U.S. (by R.A. Fessenden)
The cascade-tuning radio receiver and the heterodyne receiver are introduced.
: Edwin Armstrong patents a radio receiver circuit with positive feedback. Part of the amplified high-frequency signal is fed back to the tuning circuit to enhance selectivity and sensitivity.
FM radio is born, but only in mono.
The UM decides it needs an FM station, and expresses a commitment to radio broadcasting.
Television is born. FM is moved from its original home of 42-50 Mhz to 88-108 Mhz to make room for TV.
Advertising is accepted on WCBN-AM.
United States radio stations begin broadcasting in stereophonic sound.
In Paris an experimental digital FM transmitter begins operation.