radio

First Radio Device

1895

Guglielmo Marconi patents the first radio device, considered the foundation for modern radio.

Tesla granted a U.S. patent

1900

Nikola Tesla is granted a U.S. patent for a "system of transmitting electrical energy" and another patent for "an electrical transmitter"—both the products of his years of development in transmitting and receiving radio signals. These patents would be challenged and upheld (1903), reversed (1904), and finally restored (1943).

First Transatlantic radio signal

1901

Marconi transmits the first transatlantic radio signal, sending a message from Cornwall, England to Newfoundland.

Alternator

1904

Radio alternator designed it produce high-frequency alternating current (AC) used in early radio transmission, particularly for sending Morse code and, in some cases, voice and music

first triode invented

1906

triode invented by Lee De Forest and it made amplified radio technology possible

The Radio Act

1912

The Radio Act of 1912 assigns three- and four-letter codes to radio stations and limits broadcasting to the 360m wavelength, which jams signals.

Pittsburgh the first commercial radio program

1920

November 2: KDKA radio station in Pittsburgh broadcasts the first commercial radio program, covering the presidential election.

live music

1922

Reacting to problems posed by the Radio Act of 1912, the Commerce Department allows powerful stations to use the 400m wavelength as long as they only broadcast live music.

first radio broadcast

1924

The first radio broadcast from a Vermont location originated at the University of Vermont’s station WCAX on October 10, 1924.