Radio's 'Global Reach"

A website enables a person in Dubuque to listen to a radiostation broadcasting from a home in Sydney, Australia.

It's an everyday example of radio's progression from GuglielmoMarconi's conception of the wireless telegraph.

"It used to be the few transmitting to the masses," said AbdulSinno, chairman of the Clarke University Communication Department."Now, the masses are transmitting to the few and the masses. It isthe age of global reach of broadcasting for anybody,"

Technology has transformed the lives of broadcasters, too.

"The biggest change has been from being people intensive tocomputer and software intensive," said Tom Parsley, general managerof Radio Dubuque.

"It used to be, you would have your announcer in the studiospinning records with the engineer sitting alongside operating thedials. Now, you can basically run everything unattended. Everythingelse is an offshoot of that."

Here is a look at how radio has developed during the past 110years.

1901

A year after patenting a wireless telegraph, Guglielmo Marconiproves wireless waves were not impacted by the curvature of theearth by transmitting signals across the Atlantic Ocean.

1906

Iowa-born inventor Lee de Forest patents the Audion, a vacuumtube that receives and amplifies wireless signals.

1912

Charles Herrold is the first person to broadcast radioentertainment and information for an audience on a regularlyscheduled, pre-announced basis.

1920

Pittsburgh radio station KDKA launches as the first commercialradio broadcaster.

Listeners at home originally use crystal sets with headphones. By1930, radios were built like furniture pieces, with large speakersand single-dial tuning. Transistors replaced tubes by the 1960s.

1934

Edwin Armstrong begins filing a series of patents related to FM,an alternative radio signal to AM.

Amplitude modulation varies the amplitude, or strength, of aradio signal in accordance to the sound being transmitted. Radiosthat receive AM signals can be sensitive to static from sources suchas thunderstorms. Armstrong believed that broadcasters could varythe frequency of the signal (frequency modulation, or FM) instead ofthe amplitude and specially designed receivers would then becomeimmune to static disturbances.

Originally broadcasting on 42 to 50 megahertz, FM shifted to 88to 108 Mhz to accommodate the development of television in the mid-1940s. FM radio increased in popularity, overtaking AM stations, inthe 1970s.

1950s

Radio pioneer Gordon McLendon develops the concept of radioformats after noticing that restaurant patrons would choose to playsimilar sets of jukebox songs.

McLendon duplicated the habit by developing short play lists ofsimilar, popular songs.

1962

The launch of the Telstar communications satellite. Satelliteswould help create networks of shared programming.

1992

The FCC establishes certain segments of radio frequency forsatellite broadcasts on radio. Satellite broadcasters launched theirservices within the next decade.

2000s

The advent of digital technology means an entire day'sprogramming could be stored on a computer's hard drive.

2002

The FCC authorizes the commencement of HD (hybrid digital)broadcasts.

HD radio, also known as in-band on-channel digital radio, bundlesdigital and analog signals and provides higher-quality audio.

The system is called "hybrid" because it is neither fully analognor fully digital.

Today

Internet sites such as shoutcast.com enable users to createstreaming media Internet "radio stations."

Sources: The FCC, the California Historical Radio Society, theRadio Hall of Fame, the Nobel organizations, Columbia University