Ernst Alexanderson
Ernst Frederick Werner Alexanderson (
January 25,
1878–
May 14,
1975) was a
Swedish-American electrical engineer. Born in
Uppsala, Sweden, and educated at the
Royal Institute of Technology in
Stockholm and the
Technische Hochschule (
Technical University) in
Berlin, Germany, he spent his professional life in the US. He emigrated to the
U.S. in 1902 and spent much of his life working for the
General Electric company. He designed the
Alexanderson alternator, a high-frequency generator for longwave transmissions, which made modulated (voice) radio broadcasts practical. The only surviving transmitter in a working state is at the
Grimeton radio station outside
Varberg,
Sweden. It is a prime example of pre-electronic radio technology and was added to
UNESCO's
World heritage list in 2004.
He had been employed at
General Electric for only a short period of time when GE received an order from Canadian-born professor and researcher
Reginald Fessenden for an alternator with 1000 times higher frequency than any in existence at that time. In the summer of 1906 Dr. Alexanderson presented a 50
kHz alternator that was installed in Fessenden's radio station in
Brant Rock, Massachusetts. By fall it's output had been improved to 500 watts and 75 kHz. On Christmas Eve, 1906, Fessenden broadcast the first radio transmission with music and talk, playing the violin and reading the gospel himself. The transmission was heard as far away as the
Caribbean Sea.
Dr. Alexanderson was also instrumental in the development of television. The first
television broadcast in the United States was to his GE Plot home at 1132 Adams Rd in 1927. Over his lifetime, Dr. Alexanderson received 345 patents, the last awarded in 1973 at age 94. The inventor and engineer remained active to an advanced age, working as a consultant to GE and
RCA in the
1950's . He is buried at
Vale Cemetery in
Schenectady,
New York.
In
1983, he was inducted into the
National Inventors Hall of Fame.
* –
High frequency alternator (100
kHz), filed April, 1909; issued, November, 1911
* –
Ignition system, (
RFI suppressor), filed June, 1926; issued August, 1929
* â€"
Radio signaling system (directional antenna), filed November 1927, issued September 1930
Tuned radio frequency receiver*David E. Fisher and Marshall J. Fisher,
Tube, the Invention of Television Counterpoint, Washington D.C. USA, (1996) ISBN 1887178171
*E.F.W. Alexanderson.
General Electric Review, January, 1913
*E.F.W. Alexanderson, "Transatlantic Radio Communication", Trans. AIEE, (1919), pp. 1077-1093
*
Inventor's Hall of Fame citation accessed
April 10,
2006*
Biography at
IEEE History Center accessed
April 10,
2006*
Biography at Oldradio.com accessed
April 10,
2006*
Illustrated biography at prof. Eugenii Katz website accessed
April 10,
2006*
Fessenden and Marconi – their technologies and transatlantic experiments compared. Accessed
April 10,
2006*
Transoceanic Radio Communication in 1920, by E.F.W. Alexanderson accessed
April 10,
2006*"
A Historical Review of Continuous Wave Radio Frequency Power Generators" accessed
April 10,
2006
