F. W. Alexanderson
Ernst Alexanderson invented the
high-frequency alternator, used in radio broadcasts - National Inventors
Hall of Fame.
Ernst Alexanderson was one of America's
great inventors, with important patents in radio, television, power transmission,
Dr. Ernst Alexanderson was the General
Electric engineer who built a high-frequency alternator (a device that
converts direct current into alternating current) that greatly improved
radio communication. Prior to Alexanderson' alternator, radio was broadcast
by what was called spark machines that used dots and dashes of signals
or morse code. Ernst Alexanderson's alternator allowed radio to be broadcast
in a continuous wave. In 1901, Swedish-born Ernst Alexanderson emigrated
to the United States and began working for the General Electric Company
in Schenectady, N.Y., under Charles
Alexanderson designed his alternator
to complement the work of radio pioneer Reginald
A. Fessenden as part of a high-frequency generator. That led to Fessenden's
1906 Christmas Eve broadcast of the world's first radio program with voice
and a violin solo using Ernst Alexanderson's high-frequency alternator
for undamped oscillations.
Ernst Alexanderson was issued U.S
patent #1,008,577 on February 22, 1916 for a selective tuning device for
radios that became an integral part of modern radio systems and led to
his being honored in the Inventors Hall of Fame. He was also General Electric's
most prolific inventor, receiving a total of 322 patents.
Among Ernst Alexanderson's achievements:
with >>> The
History of Radio
He continued to improve the alternator
and in addition made important improvements in radio antennas, electric
railroads, ship propulsion, and electric motors.
On June 5, 1924, he transmitted the
first facsimile (fax) message across the Atlantic.
In 1927, he staged the first home reception
of television at his own home in Schenectady, New York, using high-frequency
neon lamps and a perforated scanning disc.
He gave the first public demonstration
of television on January 13, 1928.
From 1952 onwards, he worked for the
Radio Corporation of America (RCA) as a consultant. His 321st patent granted
in 1955 was for a color television receiver that he developed for RCA.