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Ernst Alexanderson

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Ernst Alexanderson
Alexanderson in 1920[1]
Born
Ernst Frederick Werner Alexanderson

(1878-01-25)January 25, 1878
Uppsala, Sweden
DiedMay 14, 1975(1975-05-14) (aged 97)
Schenectady, New York, U.S.
Alma mater
OccupationEngineer
Notable workAlexanderson alternator
Amplidyne
Tuned radio frequency receiver
Awards
Engineering career
DisciplineElectrical engineering
Employer(s)General Electric
Radio Corporation of America
Significant advanceRadio transmitter

Ernst Frederick Werner Alexanderson (January 25, 1878 – May 14, 1975) was a Swedish-American electrical engineer who was a pioneer in radio and television development. He invented the Alexanderson alternator, an early radio transmitter used between 1906 and the 1930s for longwave long distance radio transmission. Alexanderson also created the amplidyne, a direct current amplifier used during the Second World War for controlling anti-aircraft guns.[2]

Background

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Alexanderson was born in Uppsala, Sweden.[3] He studied at the University of Lund (1896–97) and was educated at the Royal Institute of Technology in Stockholm and the Technische Hochschule in Berlin, Germany. He emigrated to the United States in 1902 and spent much of his life working for the General Electric and Radio Corporation of America.[4]

Engineering work

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Alexanderson designed the Alexanderson alternator, an early longwave radio transmitter, one of the first devices which could transmit modulated audio (sound) over radio waves. He had been employed at General Electric for only a short time when GE received an order from Canadian-born professor and researcher Reginald Fessenden, then working for the US Weather Bureau, for a specialized alternator with much higher frequency than others in existence at that time, for use as a radio transmitter. Fessenden had been working on the problem of transmitting sound by radio waves, and had concluded that a new type of radio transmitter was needed, a continuous wave transmitter. Designing a machine that would rotate fast enough to produce radio waves proved a formidable challenge. Alexanderson's family were convinced the huge spinning rotors would fly apart and kill him, and he set up a sandbagged bunker from which to test them. In the summer of 1906 Mr. Alexanderson's first effort, a 50 kHz alternator, was installed in Fessenden's radio station in Brant Rock, Massachusetts. By fall its output had been improved to 500 watts and 75 kHz. On Christmas Eve, 1906, Fessenden made an experimental broadcast of Christmas music, including him playing the violin, that was heard by Navy ships and shore stations down the East Coast as far as Arlington. This is considered the first AM radio entertainment broadcast.[5][6]

Alexanderson continued improving his machine, and the Alexanderson alternator became widely used in high power very low frequency commercial and Naval wireless stations to transmit radiotelegraphy traffic at intercontinental distances, until by the 1930s it was replaced by vacuum tube transmitters. 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 as a UNESCO's World Heritage Site list in 2004.[7]

Alexanderson was also instrumental in the development of television. The first television broadcast in the United States was received in 1927 at his GE Plot home at 1132 Adams Rd, Schenectady, N.Y.[8] The following year he developed the coordination of sound and movement on the first television drama, The Queen's Messenger. In 1930, he conducted an early public demonstration of his large screen television system on a closed-circuit channel at Proctors in Schenectady.[9][10][11][12][13]

Alexanderson retired from General Electric in 1948. The inventor and engineer remained active to an advanced age. He continued television research as a consultant for the Radio Corporation of America filing his 321st patent application in 1955. Over his lifetime, Alexanderson received 345 US patents, the last filed in 1968 at age 89. He died in 1975 and was buried at Vale Cemetery in Schenectady, New York.[14][15]

Alexanderson is also mentioned in connection with the emergence of the patent system, that he was partially critical to. As the technology historian David Noble writes:[16]

The change in the focus of the patent system, from the protection of the inventor to the protection of the corporation which either employed the inventor or purchased his patents, was succinctly phrased by E.F.W. Alexanderson, a Swedish immigrant who became one of GE's early leading research engineers. "The patent system was established, I believe", he said, "to protect the lone inventor. In this it has not succeeded ... the patent system protects the institutions which favor invention".

Kidnapping incident

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In 1923, Alexanderson's son, Verner, was kidnapped. Alexanderson broadcast an appeal for help on the radio. The child was located after three days and returned to his family.[17] The kidnappers were later caught.

Honors

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Patents

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Ernst was very active and got a total of 345 patents granted.[22][23]

See also

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References

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  1. ^ "The March of Science", The New York Times Current History, May 1920, page 266.
  2. ^ "Ernst F. W. Alexanderson". Soylent Communications. Retrieved December 1, 2015.
  3. ^ Westerberg, H. E. (1918). "Ernst F W Alexanderson". Svenskt biografiskt lexikon (in Swedish). Vol. 1. Stockholm: National Archives of Sweden. p. 381.
  4. ^ Cafe, Kirt Blattenberger RF (September 1930). "Men Who Have Made Radio – E. F. W. Alexanderson". Radio-Craft. Retrieved December 1, 2015.
  5. ^ "Ernest Frederick Werner Alexanderson (1878–1975)". Famous Scientist Blog. January 31, 2010. Retrieved December 1, 2015.
  6. ^ John S. Belrose (September 1994). "Fessenden and the Early History of Radio Science". The Radioscientist – volume 5 number 3. Retrieved December 1, 2015.
  7. ^ "Dr. Ernst Alexanderson, Pioneer Inventor" Barry Mishkind (Oldradio.com) accessed April 10, 2006
  8. ^ "Dr Ernst Frederick Werner Alexanderson". Cherished Television UK. Archived from the original on December 8, 2015. Retrieved December 1, 2015.
  9. ^ Stashower, Daniel (2002). The Boy Genius and the Mogul The Untold Story of Television. Crown. p. 128. ISBN 9780767913218. Retrieved December 11, 2023.
  10. ^ "Initial Public Exhibit Gives New Impetus to Television". The Daily Gazette. May 23, 1930. Retrieved December 11, 2023.
  11. ^ "Alexanderson wins royal Danish medal". The Daily Gazette. November 23, 1946. Retrieved December 11, 2023.
  12. ^ Richards, Rashna Wadia (2021). Cinematic TV. Oxford University Press. p. 5. ISBN 978-0-19-007128-8. Retrieved December 11, 2023.
  13. ^ Edgerton, Gary (2007). The Columbia History of American Television. Columbia University Press. p. 36. ISBN 9780231512183. Retrieved December 11, 2023.
  14. ^ Krebs, Albin (May 15, 1975). "Dr. Ernst Alexanderson, Radio Pioneer, Dies at 97". The New York Times.
  15. ^ "Ernst F. W. Alexanderson, Biography". Engineering and Technology History. January 31, 2010. Retrieved December 1, 2015.
  16. ^ Noble 1977, pp. 87–88.
  17. ^ Carl Johnson (June 12, 2013). "The Return of Verner".
  18. ^ List of recipients of the IEEE Edison Medal
  19. ^ Brittain, J. E. (July 2004). "Electrical Engineering Hall of Fame: Ernst F. W. Alexanderson". Proceedings of the IEEE. 92 (7). IEEE: 1216–1219. doi:10.1109/JPROC.2004.828999. S2CID 29242098.
  20. ^ National Inventor's Hall of Fame Archived March 4, 2016, at the Wayback Machine citation accessed April 10, 2006
  21. ^ Biography at IEEE History Center accessed February 18, 2015
  22. ^ Ernst Fredrik Werner Alexanderson – en personcentrerad skildring av elektroteknikens utveckling under 1900-talets första hälft. Farsta : Televerket. Bengt V Nilsson. 1987. ISBN 91-972360-6-3
  23. ^ Noble, David F. (1977). America by Design: Science, Technology, and the Rise of Corporate Capitalism. Oxford University Press. ISBN 978-0-19-502618-4.

Other sources

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  • Blackwelder, Julia Kirk (2014) Electric City: General Electric in Schenectady (Texas A&M University Press) ISBN 978-1623491864
  • Brittain, James E. (1992) Alexanderson: Pioneer in American Electrical Engineering (Johns Hopkins University Press) ISBN 978-0801842283
  • Fisher, David E. and Marshall J. Fisher (1996) Tube, the Invention of Television (Counterpoint, Washington D.C) ISBN 1-887178-17-1
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