The Development of Radio
Think about radio, and what often comes to mind is the crystal clear music and
spoken words broadcast by FM stations across America. But radio wasn't always
so advanced -- or so popular. Like many technologies, it evolved gradually and
gained acceptance slowly. Today, radio continues to evolve as it competes with
other technologies to attract and hold an audience.
The first steps toward inventing radio involved discovering electromagnetic
waves and their potential. Hans Christian Oersted was the first to proclaim, in
1820, that a magnetic field is created around a wire that has a current running
through it. In 1830, English physicist Michael Faraday confirmed Oersted's
theory, and established the principle of electromagnetic induction.
In 1864, James Clerk Maxwell, an experimental physics professor at Cambridge
University, published a theoretical paper stating that electromagnetic currents
could be perceived at a distance. Maxwell also boldly postulated that such
waves travelled at the speed of light. In the late 1880s, German physicist
Heinrich Hertz tested Maxwell's theory. He succeeded in producing
electromagnetic waves, and confirmed Maxwell's prediction about their speed.
Not long after, Guglielmo Marconi, an Italian inventor, brought electromagnetic
waves out of the laboratory and into the world.
He began with short-distance broadcasts in his own back yard. In September,
1899, he astounded the world by telegraphing the results of the America's Cup
yacht races from a ship at sea to a land-based station in New York. By the end
of 1901, Marconi had founded his own commercial wireless company and broadcast
the first transatlantic signal.
For a time, wireless broadcasts were limited to coded dots and dashes. But on
December 24, 1906, Canadian-born physicist Reginald Fessenden changed that by
sending the first long-distance transmission of human voice and music from his
station at Brant Rock, Massachusetts. His signal was received as far away as
Norfolk, Virginia. The stage for commercial voice and music broadcasts was
A steady stream of inventions pushed radio forward. In 1907, American inventor
Lee De Forest introduced his patented Audion signal detector--which allowed
radio frequency signals to be amplified dramatically. Another American
inventor, Edwin Armstrong, developed the superheterodyne circuit in 1918, and
in 1933 discovered how FM broadcasts could be produced. FM provided a clearer
broadcast signal than AM, but RCA's top executive, David Sarnoff, was pushing
for the development of television. Sarnoff withheld FM from the public for more
than a decade.
Still, the public demand for radio grew exponentially. Entertainment
broadcasting began in about 1910, and included De Forest's own program, which
he aired from the Metropolitan Opera House in New York City. An entertainment
broadcasting venture based in Wilkinsburg, Pennsylvania, became the first
commercial radio station, KDKA, in 1920. The station WWJ, in Detroit, Michigan,
also one of the firsts, began commercial broadcasting in the same year. Among
the early proponents of entertainment broadcasting was Sarnoff, who used radio
to create corporate empires at RCA and NBC.
The period between the late 1920s and the early 1950s is considered the Golden
Age of Radio, in which comedies, dramas, variety shows, game shows, and popular
music shows drew millions of listeners across America. But in the 1950s, with
the introduction of television, the Golden Age faded. Still, radio remained a
pop-culture force. Developments like stereophonic broadcasting, which began in
the 1960s, helped radio maintain its popularity.
Among contemporary developments in radio is Digital Audio Broadcasting, or DAB.
In the works since the late 1980s, it had not received FCC approval as of early
1999. According to proponents, DAB provides compact disc-quality sound without
interference at any distance. DAB listeners can also become watchers:
information such as programming schedules, and traffic and weather information,
can be digitally displayed--on stereo "monitors" or LCD screens.
Already more than 100 years old, radio is still a powerful force in American
life. According to a 1998 Arbitron report, over 95 percent of Americans listen
to radio at least once a week. And with new technologies like DAB, the humble
radio wave will likely retain its power for some time to come.