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Reginald Aubrey Fessenden (*6. Oktober 1866 in East Bolton, Quebec, †22. Juli 1932) war ein kanadischer Erfinder. Fessenden ist nach Edison derjenige mit den meisten Patenten.

Fessenden, Reginald Fessenden, Reginald en:Reginald Fessenden

Quelle: en:Reginald Fessenden

Early years

As a child, the family moved to Ontario where, at an early age, Reginald Fessenden showed an interest in mathematics far beyond his years, conducting experiments that often both astounded and horrified his parents, who made certain he received a quality education. A brilliant student at Trinity College School in Port Hope, Ontario, at age fourteen he was granted a mathematics mastership to Bishop's College (now Bishop's University) in Lennoxville, Quebec. At age eighteen, he became headmaster at a school in Bermuda, but he had become fascinated with the idea of wireless telegraphy as a child when he saw Alexander Graham Bell demonstrate his telephone over a several mile distance near Bell's home in Ontario.

Middle years

Trained as an electrician, Fessenden's research subsequently took him to the United States, where he worked with Thomas Edison as a chemist developing insulation for electrical wires. In 1892 he worked with George Westinghouse to light the World Columbian Exposition in Chicago. Fessenden then became professor of electrical engineering at Purdue University, and a year later he was named head of electrical engineering at Western University of Pennsylvania.

Reginald Fessenden had considerable difficulty in attracting capital for research and development of his radical ideas. He lacked the showmanship of Marconi and Edison, and his frustration often showed in his personality, which made it nearly impossible to market himself or his inventions. In 1900 he joined the United States Weather Bureau with the understanding that the bureau could have access to any devices he invented but that he would retain ownership. On December 23, 1900 he transmitted his own voice over the first wireless telephone from a site on Cobb Island in the middle of the Potomac River near Washington, DC.

Finally, two wealthy Pennsylvania businessmen joined with him to form the National Electric Signaling Company (NESCO) to both carry on his own research and to develop Morse code services between Brant Rock, Massachusetts and several American points. In 1903 he sent a voice message to an assistant 50 miles away, and another voice sound was heard at his experimental towers in Scotland. In 1904 he was hired to help engineer the Niagara Falls power plant for the newly formed Ontario Power Commission. In 1906 he opened his own Canadian company in Montreal, and on Christmas Eve, 1906, using his heterodyne principle, Fessenden transmitted the first audio radio broadcast in history from Brant Rock, Massachusetts. Ships at sea heard a broadcast that included Fessenden playing the song O Holy Night on the violin and reading a passage from the Bible.

National Electric Signaling Company

Canadian-born Reginald Fessenden (1866-1932), one of the principal early radio inventors and the first important inventor to experiment with wireless, left the University of Pittsburgh in 1900 to work for the U.S. Weather Bureau. There he invented the liquid barretter, an early radio receiver, and attempted to work out a means for wireless transmission of weather forecasts. After a squabble over patent rights, Fessenden resigned in 1902.

The National Electric Signaling Company (NESCO), primarily intended to support Fessenden's work on wireless, telegraphy, and telephony, was formed by Fessenden and two Pittsburgh capitalists, Hay Walker, Jr. and Thomas H. Given. It began as an inventor's laboratory and never proved successful as a business venture.

Fessenden recognized that a continuous wave transmission was required for speech and he continued the work of Nikola Tesla, John Stone Stone, and Elihu Thomson on this subject. Fessenden felt he could also transmit and receive Morse code better by the continuous wave method than with a spark-apparatus as Marconi was using.

In 1903 Fessenden's first high-frequency alternator needed for continuous wave transmission was built to his specifications by Charles Steinmetz of GE. In 1906 Fessenden obtained a second alternator of greater power from GE and on Christmas Eve broadcast a program of speech and music. The work on this alternator was given to Ernst F. W. Alexanderson. It took years for Alexanderson to develop an alternator capable of transmitting regular voice transmissions over the Atlantic. But by 1916 the Fessenden-Alexanderson alternator was more reliable for transatlantic communication than the spark apparatus.

Fessenden also worked on continuous-wave reception. This work arose out of his desire for a more effective type of receiver than the coherer, a delicate device that was limited by its sensitivity on a rolling ship at sea. In 1903 he developed a new receiving mechanism - the electrolytic detector.

As his work progressed Fessenden evolved the heterodyne system. However, due to faulty construction and the fact that it was ahead of its time, heterodyne reception was not fully appreciated until the oscillating triode was devised, thus allowing a practical means of generating the local frequency.

Between 1905 and 1913 Fessenden developed a completely self-sustaining wireless system. However, constant quarrels between Fessenden, Walker, and Given culminated in Fessenden's forming the Fessenden Wireless Company of Canada. He felt a Canadian company could better compete with British Marconi. As a result, his backers dismissed Fessenden from NESCO in January of 1911. Fessenden brought suit, won, and was awarded damages. To conserve assets pending appeal, NESCO went into receivership in 1912, and Samuel Kintner was appointed general manager of the company.

In 1917 Given and Walker formed International Signal Company (ISC) and transferred NESCO's patent assets to the new company. Westinghouse obtained majority control of ISC through the purchase of $2,500,000 worth of stock. The company was then reincorporated as The International Radio Telegraph Company. The Westinghouse-RCA agreements were signed in 1921 and International's assets were transferred to RCA.

Marconi had sent radio signals from England to Newfoundland in 1901, but these were one-way only and in Morse Code. Fessenden's achievement was significant in that it was a two-way voice transmission by radio between Scotland and Massachusetts. Still, the potential for his invention was not recognized, and even his own backers were not interested in voice or music communication, and their business partnership dissolved. A lengthy lawsuit would follow that, years later, resulted in a large settlement in Fessenden's favour.

Working for a company in Boston, Reginald Fessenden developed a wireless system for submarines to signal each other as well as a device using radio waves designed to locate icebergs miles away, thus avoiding another Titanic disaster. At the outbreak of World War I, Fessenden volunteered his services to the Canadian government and was sent to London, England where he developed a device to detect enemy artillery and another to locate enemy submarines.

Later years

An inveterate tinkerer, Reginald Fessenden eventually become the holder of more than 500 patents, including a version of microfilm. He patented the basic ideas leading to reflection seismology, a technique important for its use in exploring for petroleum. In 1915 he invented the fathometer, a sonar device used to determine the depth of water for a submerged object by means of sound waves, for which he won Scientific American's Gold Medal in 1929. The Institute of Radio Engineers presented him with its Medal of Honor, and Philadelphia awarded him a medal and cash prize for "One whose labors had been of great benefit to."

Death and afterwards

Reginald Fessenden died at his vacation home in Bermuda and was interred there at St. Mark's Church cemetery. His private Boston residence at 45 Waban Hill Road in the Chestnut Hill district of Newton, Massachusetts is on the National Register of Historic Places.

A New York Herald Tribune editorial said:

It sometimes happens, even in science, that one man can be right against the world. Professor Fessenden was that man. He fought bitterly and alone to prove his theories. It was he who insisted, against the stormy protests of every recognized authority, that what we now call radio was worked by continuous waves sent through the ether by the transmitting station as light waves are sent out by a flame. Marconi and others insisted that what was happening was a whiplash effect. The progress of radio was retarded a decade by this error. The whiplash theory passed gradually from the minds of men and was replaced by the continuous wave — one with all too little credit to the man who had been right.

Patents

Vorlage:US patent, "Induction coil for x-ray apparatus
Vorlage:US patent, "X-ray apparatus".
Vorlage:US patent, "Induction-coil"
Vorlage:US patent, "Apparatus for wireless telegraphy". (ed. compressed air spark gap)
Vorlage:US patent, "Apparatus for signalling by electromagnetic waves".
Vorlage:US patent, "Receiver for electromagnetic waves"
Vorlage:US patent, "Receiver for signalling"
Vorlage:US patent, "Signalling by electromagnetic waves"
Vorlage:US patent, "Signalling by electromagnetic waves"
Vorlage:US patent, "Receiver for electromagnetic waves"
Vorlage:US patent, "Signalling for electromagnetic waves"
Vorlage:US patent, "Signalling by sound and other longitudal elastic impulses".
Vorlage:US patent, "Infusor".

Reissued

Vorlage:US patent "Receiver for electromagnetic waves"

External links

Belrose, John S., "Fessenden and Marconi: Their Differing Technologies and Transatlantic Experiments During the First Decade of this Century". International Conference on 100 Years of Radio (5-7 September 1995).
George H. Clark Radioana Collection, ca. 1880 - 1950 - National Museum of American History, Smithsonian Institution.