Ernst Frederick Werner Alexanderson (January 25, 1878 – May 14, 1975) was a
Swedish-American
Swedish Americans ( sv, svenskamerikaner) are Americans of Swedish ancestry. They include the 1.2 million Swedish immigrants during 1865–1915, who formed tight-knit communities, as well as their descendants and more recent immigrants.
Today, ...
electrical engineer
Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...
, who was a pioneer in
radio
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmit ...
and
television
Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertisin ...
development. He invented the
Alexanderson alternator
An Alexanderson alternator is a rotating machine invented by Ernst Alexanderson in 1904 for the generation of high-frequency alternating current for use as a radio transmitter. It was one of the first devices capable of generating the continuou ...
, an early
radio transmitter
In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the ...
used between 1906 and the 1930s for
longwave
In radio, longwave, long wave or long-wave, and commonly abbreviated LW, refers to parts of the radio spectrum with wavelengths longer than what was originally called the medium-wave broadcasting band. The term is historic, dating from the e ...
long distance radio transmission. Alexanderson also created the
amplidyne
An amplidyne is an obsolete electromechanical amplifier invented prior to World War II by Ernst Alexanderson. It consists of an electric motor driving a DC generator. The signal to be amplified is applied to the generator's field winding, and ...
, a direct current amplifier used during the
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
for controlling anti-aircraft guns.
Background
Alexanderson was born in
Uppsala, Sweden
Uppsala (, or all ending in , ; archaically spelled ''Upsala'') is the county seat of Uppsala County and the List of urban areas in Sweden by population, fourth-largest city in Sweden, after Stockholm, Gothenburg, and Malmö. It had 177,074 inha ...
. He studied at the
University of Lund
, motto = Ad utrumque
, mottoeng = Prepared for both
, established =
, type = Public research university
, budget = SEK 9 billion [Royal Institute of Technology
The KTH Royal Institute of Technology ( sv, Kungliga Tekniska högskolan, lit=Royal Institute of Technology), abbreviated KTH, is a public research university in Stockholm, Sweden. KTH conducts research and education in engineering and technolo ...]
in
Stockholm
Stockholm () is the Capital city, capital and List of urban areas in Sweden by population, largest city of Sweden as well as the List of urban areas in the Nordic countries, largest urban area in Scandinavia. Approximately 980,000 people liv ...
and the
Technische Hochschule
A ''Technische Hochschule'' (, plural: ''Technische Hochschulen'', abbreviated ''TH'') is a type of university focusing on engineering sciences in Germany. Previously, it also existed in Austria, Switzerland, the Netherlands (), and Finland (, ). ...
in
Berlin
Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...
,
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
. He emigrated to the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
in 1902 and spent much of his life working for the
General Electric
General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable energ ...
and
Radio Corporation of America
The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Comp ...
.
Engineering work
Alexanderson designed the
Alexanderson alternator
An Alexanderson alternator is a rotating machine invented by Ernst Alexanderson in 1904 for the generation of high-frequency alternating current for use as a radio transmitter. It was one of the first devices capable of generating the continuou ...
, an early
longwave
In radio, longwave, long wave or long-wave, and commonly abbreviated LW, refers to parts of the radio spectrum with wavelengths longer than what was originally called the medium-wave broadcasting band. The term is historic, dating from the e ...
radio transmitter
In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the ...
, one of the first devices which could transmit modulated audio (sound) over radio waves. He had been employed at
General Electric
General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable energ ...
for only a short time when GE received an order from Canadian-born professor and researcher
Reginald Fessenden
Reginald Aubrey Fessenden (October 6, 1866 – July 22, 1932) was a Canadian-born inventor, who did a majority of his work in the United States and also claimed U.S. citizenship through his American-born father. During his life he received hundre ...
, 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
Radio waves are a type of electromagnetic radiation with the longest wavelengths in the electromagnetic spectrum, typically with frequencies of 300 gigahertz (GHz) and below. At 300 GHz, the corresponding wavelength is 1 mm (short ...
, and had concluded that a new type of radio transmitter was needed, a
continuous wave
A continuous wave or continuous waveform (CW) is an electromagnetic wave of constant amplitude and frequency, typically a sine wave, that for mathematical analysis is considered to be of infinite duration. It may refer to e.g. a laser or particle ...
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
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that on ...
alternator, was installed in Fessenden's radio station in
Brant Rock, Massachusetts
Ocean Bluff-Brant Rock is a census-designated place (CDP) in Plymouth County, Massachusetts, United States, composed of the neighborhoods of Ocean Bluff, Brant Rock, Fieldston, and Rexhame in the town of Marshfield. The population of the CDP ...
. 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.
Alexanderson continued improving his machine, and the Alexanderson alternator became widely used in high power
very low frequency
Very low frequency or VLF is the ITU designation for radio frequencies (RF) in the range of 3–30 kHz, corresponding to wavelengths from 100 to 10 km, respectively. The band is also known as the myriameter band or myriameter wave a ...
commercial and Naval wireless stations to transmit radiotelegraphy traffic at intercontinental distances, until by the 1930s it was replaced by
vacuum tube
A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied.
The type kn ...
transmitters. The only surviving transmitter in a working state is at the
Grimeton radio station outside
Varberg
Varberg () is a locality and the seat of Varberg Municipality, Halland County, Sweden, with 35,782 inhabitants in 2019.
Varberg and all of Halland are well known for their "typical west coast" sandy beaches. In Varberg the coast changes from wi ...
,
Sweden
Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...
. It is a prime example of pre-electronic radio technology and was added as a
UNESCO
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...
's
World Heritage Site
A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for h ...
list in 2004.
Alexanderson was also instrumental in the development of
television
Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertisin ...
. The first television broadcast in the United States was received in 1927 at his
GE Plot home at 1132 Adams Rd,
Schenectady, N.Y.
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
Vale Cemetery is a historic rural cemetery and the largest cemetery in Schenectady, New York. It opened on 21 October 1857 when the Rev. Julius Seely dedicated what was then termed "the Vale". It has tripled its size since opening and today it ...
in
Schenectady
Schenectady () is a city in Schenectady County, New York, United States, of which it is the county seat. As of the 2020 census, the city's population of 67,047 made it the state's ninth-largest city by population. The city is in eastern New Y ...
,
New York
New York most commonly refers to:
* New York City, the most populous city in the United States, located in the state of New York
* New York (state), a state in the northeastern United States
New York may also refer to:
Film and television
* '' ...
.
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:
Kidnapping incident
In 1923, Alexanderson's son, Verner, was kidnapped. He was located after three days and returned to his family.
Honors
*
IEEE Medal of Honor
The IEEE Medal of Honor is the highest recognition of the Institute of Electrical and Electronics Engineers (IEEE). It has been awarded since 1917, when its first recipient was Major Edwin H. Armstrong. It is given for an exceptional contribution ...
from the Institute of Radio Engineers, now
IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation ...
, (1919)
*
IEEE Edison Medal
The IEEE Edison Medal is presented by the Institute of Electrical and Electronics Engineers (IEEE) "for a career of meritorious achievement in electrical science, electrical engineering, or the electrical arts." It is the oldest medal in this fi ...
from the American Institute of Electrical Engineers, now
IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation ...
, (1944)
*
Valdemar Poulsen Gold Medal from the (1947)
*
National Inventors Hall of Fame
The National Inventors Hall of Fame (NIHF) is an American not-for-profit organization, founded in 1973, which recognizes individual engineers and inventors who hold a U.S. patent of significant technology. Besides the Hall of Fame, it also opera ...
induction (1983)
*
Consumer Electronics Hall of Fame
The Consumer Electronics Hall of Fame, founded by the Consumer Electronics Association (CEA), honors leaders whose creativity, persistence, determination and personal charisma helped to shape the industry and made the consumer electronics marketpla ...
induction (2002)
Biography
at IEEE History Center accessed February 18, 2015
Patents
Ernst was very active and got a total of 345 patents
A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A p ...
granted.[''Ernst Fredrik Werner Alexanderson – en personcentrerad skildring av elektroteknikens utveckling under 1900-talets första hälft.'' Farsta : Televerket. Bengt V Nilsson. 1987. ][''America by Design.'' Oxford: Oxford University Press. David Noble. 1977.]
* – ''High frequency alternator'' (100 kHz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that on ...
), filed April 1909; issued, November 1911
* – ''Selective Tuning System'' ( Tuned RF Circuit, filed October 1913; issued February 1916
* – ''Ignition system'', ( RFI suppressor), filed June 1926; issued August 1929
* – ''Radio signaling system'' (directional antenna), filed November 1927, issued September 1930
See also
* Amplidyne
An amplidyne is an obsolete electromechanical amplifier invented prior to World War II by Ernst Alexanderson. It consists of an electric motor driving a DC generator. The signal to be amplified is applied to the generator's field winding, and ...
* Tuned radio frequency receiver
A tuned radio frequency receiver (or TRF receiver) is a type of radio receiver that is composed of one or more tuned radio frequency (RF) amplifier stages followed by a detector (demodulator) circuit to extract the audio signal and usually an ...
References
Other sources
*Blackwelder, Julia Kirk (2014) ''Electric City: General Electric in Schenectady'' (Texas A&M University Press)
*Brittain, James E. (1992) ''Alexanderson: Pioneer in American Electrical Engineering'' (Johns Hopkins University Press)
*Fisher, David E. and Marshall J. Fisher (1996) ''Tube, the Invention of Television'' (Counterpoint, Washington D.C)
Related reading
*Alexanderson, E.F.W. (August 1920
''Trans-oceanic Radio Communication''
(Proceedings of the I.R.E., pp. 263–285)
External links
*
at prof. Eugenii Katz website accessed April 10, 2006
Bibliography related to Alexanderson's contribution to history of television
a
Histoire de la télévision"
site
– their technologies and transatlantic experiments compared. Accessed April 10, 2006
*
{{DEFAULTSORT:Alexanderson, Ernst
1878 births
1975 deaths
Electronics engineers
Swedish electrical engineers
Radio pioneers
Television pioneers
People from Schenectady, New York
KTH Royal Institute of Technology alumni
IEEE Medal of Honor recipients
IEEE Edison Medal recipients
Valdemar Poulsen Gold Medal recipients
Swedish emigrants to the United States
American electrical engineers
Swedish engineers
20th-century American engineers
20th-century American inventors
RCA people
Engineers from New York (state)
Knights of the Order of the Polar Star
American telecommunications engineers