Dear wolvies,
Voice broadcast is almost as old as electric pulse broadcast. While
the technical basics of practical pulse-based broadcast were developed
after 1895 by Alexander Popov (1858-1906), Guglielmo Marconi
(1874-1937), Adolf Slaby (1849-1913), Georg von Arco (1869-1940), and
Karl Ferdinand von Braun (1850-1918), voice broadcast developed by
Canadian scientiest Professor Reginald Fessenden (1866-1932) as early
as 1900.
Fessenden, head of the electrical engineering department at Western
University in Pittsburgh since 1893, was fascinated by the radio
experiments Guglielmo Marconi conducted in England. However, the
Marconi system only allowed the transmission of Morse code.
Fessenden's goal was to transmit sounds like the human voice and
music. To accomplish this he devised the theory of the "continuous
wave", a means to superimpose sound onto a radio wave and transmit
this signal to a receiver where the radio wave would be removed,
leaving the listener with the original sound. The continuous wave is
the electronic basis that make radio and television transmission
possible.
In 1900 he joined the United States Weather Bureau on the
understanding that the bureau could have access to any devices he
invented but that he would retain ownership. On December 23, 1900, he
transmitted his own voice over the first wireless telephone from a
site on Cobb Island in the middle of the Potomac River near
Washington, DC.
He continued working on his voice broadcast system and finally, on
Christmas Eve 1906, Fessenden transmitted the first radio broadcast
from Brant Rock Station, Massachusetts. Ships at sea heard a broadcast
that included Fessenden playing "O Holy Night" on the violin and
reading a passage from the Bible.
At this point, Fesseneden was not the only one anymore to work on
voice broadcast. Under their technical director Georg von Arco, the
German Telefunken company had also developed a such system. On 16
December 1906, Telefunken engineers managed to transmit a human voice
broadcast over a distance of 40 kilometers.
However, the arc transmitters used for early voice broadcast devices
were not very reliable. So in spite of all additional developments on
this area prior to World War I, voice broadcast did not have a real
future before the invention of electronic tubes and their use for more
dependable broadcast devices. The tube was invented simultanously by
Austrian scientist Robert von Lieben (1878-1913) and the American RCA
engineer Lee de Forest (1863-1961). In 1912/1913, both de Forest at
RCA and Alexander Meißner (1883-1958) at Telefunken constructed
tube-based voice broadcast transmitters, which were far more reliable
than arc transmitters. In June, 1913, wireless two-way voice
communication was successfully achieved by Telefunken engineers on the
40-km-distance between Berlin and Nauen (Germany).
At this point, future use of voice broadcast was seen mainly in the
military and nautical areas; but Telefunken director Hans Bredow
already had a vision of one-way broadcast for audiences. To
demonstrate the potential of voice broadcast on this field to the
public, he transmitted music performances from Sayville radio station
(USA). Before he could further develop this idea, war broke out and in
the five years to come, Bredow would press ahead with the development
of voice radio for the German military. But his vision of
entertainment broadcasting was not forgotten in the United States.
During World War I, wireless voice broadcast saw quick progress due to
fast technical development for military purposes. All major nations
involved in the war used wireless voice transmission. When the war was
over in 1918, the technology was much more reliable and advanced than
five years before. The progress of the war years had made voice radio
broadcast fit for going public as one-way entertainment media, and
also as dependable two-way means of communication.
On 8 November 1920, KDKA-AM in Pittsburgh signed on officially and was
the 1st commercially licensed radio station in the world.
Sources:
Telekommunikation, by Michael Reuter. Published by Decker, 1990. ISBN
3-7685-0990-7.
Wikipedia: Reginald Fessenden
http://www.wikipedia.org/wiki/Reginald_Fessenden
National Museum of Broadcasting: Reginald Fessenden
http://trfn.clpgh.org/nmb/nmbfess.htm
About.com: Inventors - Reginald Fessenden
http://inventors.about.com/library/inventors/blfessenden.htm
National Inventors Hall of Fame: Reginald Fessenden
http://www.invent.org/hall_of_fame/59.html
Ohio Valley Radio & TV: Pittsburgh AM Radio
http://www.geocities.com/ovrtv/pittsburgh/am.html
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Hope this answers your question!
Best regards,
Scriptor |
