Engineering Hall of Fame

Ernst F. W. Alexanderson
The accomplishments and life of E. F. Alexanderson, 1878-1975

E. F. W. Alexanderson

Ernst Alexanderson: "Father of Radio and Television" - Guillermo Marconi.

Ernst Fredrik Werner Alexanderson was born January 25, 1878 in Uppsala, Sweden. His father, Professor A.M. Alexanderson was a teacher at the University of Uppsala. Because of an aptitude for mechanics, he entered the Royal Technical University in Stockholm and was graduated as an electrical and mechanical engineer. For a year of post graduate study in electrical engineering, he attended the Technical University in Berlin, Germany.

As the son of a professor of languages, Alexanderson as a boy learned English, German, French and Latin in addition to his native Swedish. When an English copy of Alternating Current Phenomena by Charles P. Steinmetz fell into Alexanderson's hands in Berlin he was able to read the volume. It made such an impression on him that he decided to move to America and seek work with Steinmetz.

In 1901 Alexanderson arrived in the United States and visited Dr. Steinmetz in Schenectady. After five months which he spent as a draftsman for the C and C Electrical Company in New Jersey, General Electric in Schenectady in February 1902 gave Alexanderson a drafting job on the recommendation of Steinmetz. The next year he took the General Electric Test Engineering Course and in 1904 he became a member of the engineering staff designing generators under the direction of Steinmetz.

Reginald Fesseden


First Long Distance Voice Transmission:

Ernst Alexanderson made the power breakthrough that allowed Reginald Fessenden to transmit the human voice across a long distance in 1906.

Fessenden needed a continuous wave transmitter, a pure sine wave on a single frequency to make voice, he turned to GE:

An assignment to build a high-frequency alternator for Professor Reginald A. Fessenden, one of the pioneer radio experimenters, gave Alexanderson his opportunity. Fessenden contracted with General Electric to help design and produce a series of high-frequency alternator-transmitters. In 1903, Charles Proteus Steinmetz of GE delivered a 10 kHz version which proved of limited use and could not be directly used as a radio transmitter. Fessenden's request for a faster, more powerful unit was assigned to Ernst F. W. Alexanderson

After two years of work, during which several models were constructed, Alexanderson delivered a practical alternator and it was installed in the Fessenden station at Brant Rock, Massachusetts. On Christmas Eve of 1906, it enabled this station to transmit the first broadcast in history. Alexanderson improved this machine by substituting iron for wood in the armature. With more improvements in 1908 and 1911 this became the famous Alexanderson alternator. It assured reliable trans-Atlantic radio communication.


The end of World War I found the British-controlled Marconi Company renewing negotiations, first instituted in 1915, for exclusive use of the Alexanderson Alternator. To prevent its falling into foreign hands government officials encouraged formation of the Radio Corporation of America to use it. General Electric refused the Marconi offer and backed the new corporation of which Dr. Alexanderson became chief engineer in 1919.

Meanwhile, he had developed a host of other radio improvements, some of which became increasingly important as vacuum tubes replaced the alternators. One of these, a tuned radio-frequency receiver system providing selective tuning, patented in 1916, was found to dominate the radio industry. Other notable Alexanderson radio developments include the magnetic amplifier, the electronic amplifier, the multiple tuned antenna, the antistatic receiving antenna and the directional transmitting antenna. He has also devised radio altimeters. His studies in the polarization of radio waves made possible effective radio direction finders.

The two Alexanderson alternators at Grimeton, Sweden

From 1919 to 1924 Dr. Alexanderson divided his time between General Electric and the Radio Corporation, maintaining his residence and laboratory in Schenectady but personally superintending construction of powerful radio stations in Sweden, Poland, England, Hawaii, California and on Long Island. At the opening of a trans-Atlantic station at Grimeton, in his native Sweden, Dr. Alexanderson received the Order of the North Star from the hands of King Gustav V.

Grimeton, Sweden

Learn more about Grimeton, Sweden:

Grimeton - The Link to America (site of the historic 1925 trans-atlantic voice transmission) Click above to visit the Swedish website in english to learn more abou the site, or to help you arrange a visit!

Tel: +46 0340-67 41 90
email: lars.g.johansson at

Dr. Alexanderson and his TV projector which was used a Proctors Theater for the first public demonstration of television

In the next few years, Dr. Alexanderson did notable pioneer work in television and the transmission of pictures by radio. Using a perforated scanning disk and high-frequency neon lamps, he staged in Schenectady the first home and theater television demonstrations. The first home reception of television took place in 1927 at Dr. Alexanderson's home (see photo below).

The first home television reception in the world 1927

With the separation of the General Electric Company and the Radio Corporation of America in 1932, Dr. Alexanderson devoted himself to power application of the electronic science such as power transmission with direct current. However he continued his interest in short-wave phenomena and in television.

In addition to his radio achievements, Dr. Alexanderson has produced an ever lengthening list of inventions in the power and control fields. These account for many of his patents obtained over a period of thirty-five years on an average of roughly a new patent every seven weeks.

In 1934 Dr. Alexanderson was elected to the Royal Academy of Science of Sweden, the body which bestows the Nobel prizes in science. Besides the Swedish Order of the North Star, Dr. Alexanderson has received the Medal of Honor of the Institute of Radio Engineers (1919), knighthood of the Polish Order of Polonia Restituta (1924), and the John Ericsson medal for outstanding contributions to the field of radio engineering (1928). He is a member and past president of the Institute of Radio Engineers and a fellow of the American Institute of Electrical Engineers. He has honorary degrees of Doctor of Science from Union College, Schenectady (1926), and Doctor of Philosophy from the Royal University of Uppsala, Sweden (1938). In 1940 his name was listed on a "Wall of Fame" honoring foreign born citizens who have made notable contributions to American democracy. This was unveiled at the New York World's Fair.

Alexanderson: still experimenting into his 90's

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. Dr. Alexanderson died May 14, 1975 and is buried in Vale Cemetery in Schenectady, NY.

See also the FCC radio history project for more on the contributions of Ernst Alexanderson.

Hear the voice of Dr. Alexanderson in this video (he is featured in the middle) (YouTube Video)


Books on Alexanderson:

"Ernst Fredrik Werner Alexanderson" by Bengt V. Nilsson get it at

Visit the Edison Tech Center in Schenectady to see our collection of historic books on Alexanderson

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Photos from the Schenectady Historical Society, The Schenectady Museum, also from
General Electric company photographers,and the Edison Tech Center archives

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