Reginald Fessenden
Reginald Fessenden | |
---|---|
Radiotelephony, sonar, Amplitude modulation | |
Spouse | Helen May Trott Fessenden |
Reginald Aubrey Fessenden (October 6, 1866 – July 22, 1932) was a Canadian-born inventor who received hundreds of
.Fessenden is best known for his pioneering work developing radio technology, including the foundations of amplitude modulation (AM) radio. His achievements included the first transmission of speech by radio (1900), and the first two-way radiotelegraphic communication across the Atlantic Ocean (1906). In 1932 he reported that, in late 1906, he also made the first radio broadcast of entertainment and music, although a lack of verifiable details has led to some doubts about this claim.
He did a majority of his work in the United States and, in addition to his Canadian citizenship, claimed U.S. citizenship through his American-born father.[1]
Early years
Reginald Fessenden was born October 6, 1866, in
While growing up Fessenden attended a number of educational institutions. At the young age of nine he was enrolled in the DeVeaux Military school for a year. He next attended Trinity College School in Port Hope, Ontario, from 1877 until the summer of 1879. He also spent a year working for the Imperial Bank at Woodstock because he had not yet reached the age of 16 needed to enroll in college.
At the age of fourteen, he returned to his hometown in the Eastern Townships and went to the nearby Bishop's College School, which granted him a mathematics mastership (teaching job)[3] and a scholarship for studying in its college division at University of Bishop's College. Thus, while Fessenden was still a teenager, he taught mathematics to the school's younger students (some older than himself) for four years, while simultaneously studying natural sciences with older students at the college.[4][5]
At the age of eighteen, Fessenden left Bishop's without having been awarded a degree, although he had "done substantially all the work necessary", in order to accept a position at the
Early work
Fessenden's classical education provided him with only a limited amount of scientific and technical training. Interested in increasing his skills in the electrical field, he moved to New York City in 1886, with hopes of gaining employment with the famous inventor, Thomas Edison. However, his initial attempts were rebuffed; in his first application Fessenden wrote, "Do not know anything about electricity, but can learn pretty quick," to which Edison replied, "Have enough men now who do not know about electricity." However, Fessenden persevered, and before the end of the year was hired for a semi-skilled position as an assistant tester for the Edison Machine Works, which was laying underground electrical mains in New York City. He quickly proved his worth, and received a series of promotions, with increasing responsibility for the project. In late 1886, Fessenden began working directly for Edison at the inventor's new laboratory in West Orange, New Jersey, as a junior technician.[7] He participated in a broad range of projects, which included work in solving problems in chemistry, metallurgy, and electricity. However, in 1890, facing financial problems, Edison was forced to lay off most of the laboratory employees, including Fessenden.[10] (Fessenden remained an admirer of Edison his entire life, and in 1925 stated that "there is only one figure in history which stands in the same rank as him as an inventor, i. e. Archimedes".)[11]
Taking advantage of his recent practical experience, Fessenden was able to find positions with a series of manufacturing companies. In 1892, he received an appointment as professor for the newly formed Electrical Engineering department at
Radio work
In the late 1890s, reports began to appear about the success
Weather Bureau contract
In 1900 Fessenden left Pittsburgh to work for the
As his work progressed, Fessenden also developed the
Fessenden's initial Weather Bureau work took place at Cobb Island, Maryland, located in the Potomac River about 80 kilometers (50 mi) downstream from Washington, D.C. As the experimentation expanded, additional stations were built along the Atlantic Coast in North Carolina and Virginia. However, in the midst of promising advances, Fessenden became embroiled in disputes with his sponsor. In particular, he charged that Bureau Chief Willis Moore had attempted to gain a half-share of the patents. Fessenden refused to sign over the rights, and his work for the Weather Bureau ended in August 1902.[18]
National Electric Signaling Company
In November 1902, two wealthy Pittsburgh businessmen, Hay Walker Jr. and Thomas H. Given, financed the formation of the National Electric Signaling Company (NESCO) to support Fessenden's research. Initially the new company was based in Washington, D.C., where a station was constructed for experimental and demonstration purposes. Two additional demonstration stations were constructed at Collingswood, New Jersey (near Philadelphia) and Jersey City, New Jersey (near New York City).[20] In 1904 an attempt was made to link the General Electric plants in Schenectady, New York, and Lynn, Massachusetts, a distance of 185 miles (298 km), however the effort was unsuccessful.[21]
Efforts to sell equipment to the U.S. and other governments, as well as private companies, met with little success. An ongoing area of conflict, especially with the U.S. Navy, were the high prices Fessenden tried to charge. The Navy in particular felt Fessenden's quotes were too far above the device's manufacturing costs to be considered reasonable, and contracted with other companies to build equipment that used Fessenden designs. This led to bad feelings and a series of patent infringement lawsuits. An alternate plan to sell the company as a whole was unsuccessful in finding a buyer. Eventually a radical change in company orientation took place. In 1904 it was decided to compete with the existing ocean cables, by setting up a transatlantic radiotelegraph link. The headquarters for company operations was moved to
Rotary-spark transmitter and the first two-way transatlantic transmission
The plan was to conduct the transatlantic service using Fessenden-designed rotary spark-gap transmitters. A 420-foot (128 meter) guyed antenna was constructed at Brant Rock, with a similar tower erected at Machrihanish in western Scotland. In January 1906, these stations made the first successful two-way transmission across the Atlantic, exchanging Morse code messages. (Marconi had only achieved one-way transmissions at this time.) However, the system was unable to reliably bridge this distance when the sun was up, or during the summer months when interference levels were higher, so work was suspended until later in the year. Then, on December 6, 1906, the Machrihanish radio tower collapsed in a gale,[23] abruptly ending the transatlantic project before it could begin commercial service. (A detailed review in Engineering magazine blamed the collapse on sub-standard construction, due to "the way in which the joints were made by the man employed for the purpose by the sub-contractors to whom the work was entrusted by the Brown Hoisting Machinery Company" and "The only wonder is that the tower did not fall before.")[24]
In a letter published in the January 19, 1907, issue of Scientific American, Fessenden discounted the effect of the tower collapse, stating that "The working up to the date of the accident was, however, so successful that the directors of the National Electric Signaling Company have decided that it is unnecessary to carry on the experimental developments any further, and specifications are being drawn up for the erection of five stations for doing transatlantic and other cable work, and a commercial permit is being applied for in England."[25] However, the tower collapse did in fact mark the end of NESCO's transatlantic efforts.[26]
Audio transmissions
Fessenden had a very early interest in the possibility of making audio radio transmissions, in contrast to the early spark-gap transmissions that could only transmit Morse code messages. As early as 1891, he had investigated sending alternating currents of varying frequencies along telegraph lines, in order to create a multiplex telegraph system.[27] He would later apply the knowledge gained about tuning and resonance from his alternating current electrical work to the higher frequency currents used in radio, in order to develop the concept of continuous-wave radio signals.[28]
Fessenden's basic approach was disclosed in U.S. Patent 706,737, which he applied for on May 29, 1901, and was issued the next year. It called for the use of a high-speed alternator (referred to as "an alternating-current dynamo") that generated "pure sine waves" and produced "a continuous train of radiant waves of substantially uniform strength", or, in modern terminology, a continuous-wave (CW) transmitter.[29] The idea of using continuous-wave radio signals was in direct conflict with the current orthodoxy that the abrupt "whiplash" effect produced by large electrical sparks was needed in order to create adequately strong signals. John Ambrose Fleming, a Marconi associate, was particularly dismissive in his book The Principles of Electric Wave Telegraphy, a detailed review of the state of the art as he saw it that was published in 1906. Reviewing Fessenden's patent, he wrote that "The creation of an electric wave seems to involve a certain suddenness in the beginning of the oscillations, and an alternator giving a simple sine-curve would not be likely to produce the required effect..."[30] (In view of Fessenden's ultimate success, this statement disappeared from the book's 1916 edition.) Fessenden's next step, taken from standard wire-telephone practice, was to insert a simple carbon microphone into the transmission line, which was used to modulate the carrier wave signal for audio transmissions, or, again using modern terms, used to produce amplitude modulated (AM) radio signals.[31]
Fessenden began his research on audio transmissions while still on Cobb Island. Because he did not yet have a continuous-wave transmitter, initially he worked with an experimental "high-frequency spark" transmitter, taking advantage of the fact that the higher the spark rate, the closer a spark-gap transmission comes to producing continuous waves. He later reported that, on December 23, 1900, he successfully transmitted speech over a distance of about 1.6 kilometers (one mile), saying; “One, two, three, four. Is It snowing where you are, Mr. Thiessen? If so, telegraph back and let me know”, which appears to have been the first successful audio transmission using radio signals.[32][33] However, at this time the sound was far too distorted to be commercially practical, although as a test this did show that with further refinements it would become possible to effectively transmit sounds by radio.[34]
For a time Fessenden continued working with more sophisticated high-frequency spark transmitters, including versions that used compressed air, which began to take on some of the characteristics of arc-transmitters patented by Valdemar Poulsen.[35] Fessenden unsuccessfully attempted to sell this form of radiotelephone, later noting: "In 1904, with a 20,000 frequency spark and compressed nitrogen gap, such good results were obtained that a demonstration was given to a number of electrical engineers, who signed affidavits that they considered the articulation as commercially good over twenty-five miles, and the sets were advertised for sale..."[36] (In a 1908 review, he conceded that with this approach "The transmission was, however, still not absolutely perfect.")[37]
Alternator-transmitter
Fessenden's ultimate plan for an audio-capable transmitter was to take a basic electrical alternator, which normally rotated at speeds that produced alternating current of at most a few hundred cycles-per-second (Hz), and greatly increase its rotational speed, in order to create electrical currents of tens-of-thousands of cycles-per-second (kHz), thus producing a steady continuous-wave transmission when connected to an aerial. However, it would take many years of expensive development before even a prototype alternator-transmitter would be ready, and a few years beyond that for high-power versions to become available. One concern was whether at these high speeds the alternator might disintegrate due to the high rotation speed tearing it apart. Because of this, as a precaution, while the alternator was being initially developed it was "placed in a pit surrounded by sandbags".[38]
Fessenden contracted with General Electric (GE) 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, who in August 1906 delivered an improved model which operated at a transmitting frequency of approximately 50 kHz, although with far less power than Fessenden's rotary-spark transmitters.[39]
The alternator-transmitter achieved the goal of transmitting quality audio signals, but the lack of any way to amplify the signals meant they were somewhat weak. On December 21, 1906, Fessenden made an extensive demonstration of the new alternator-transmitter at Brant Rock, showing its utility for point-to-point wireless telephony, including interconnecting his stations to the wire telephone network. As part of the demonstration, speech was transmitted 18 kilometers (11 miles) to a listening site at Plymouth, Massachusetts. A detailed review of this demonstration appeared in The American Telephone Journal[32] and a summary by Fessenden appeared in Scientific American.[40] A portion of a report produced by Greenleaf W. Pickard of the Telephone Company's Boston office, which includes additional information on some still existing defects, appeared in Ernst Ruhmer's Wireless Telephony in Theory and Practice.[41]
Although primarily designed for transmissions spanning a few kilometers, on a couple of occasions the test Brant Rock audio transmissions were apparently overheard by NESCO employee James C. Armor across the Atlantic at the Machrihanish site.[42]
First entertainment radio broadcast
Until the early 1930s, it was generally accepted that Lee de Forest, who conducted a series of test broadcasts beginning in 1907, and who was widely quoted promoting the potential of organized radio broadcasting, was the first person to transmit music and entertainment by radio. De Forest's first entertainment broadcast occurred in February 1907, when he transmitted electronic telharmonium music from his laboratory station in New York City.[43] This was followed by tests that included, in the fall, Eugenia Farrar singing "I Love You Truly".[44] (Beginning in 1904, the U.S. Navy had broadcast daily time signals and weather reports, but these employed spark transmitters, transmitting in Morse code).
In 1928, as part of a lecture reviewing "The Early History of Radio in the United States", H. P. Davis, commenting on entertainment offerings, asserted that "Reginald Fessenden, probably the first to attempt this, broadcast a program Christmas Eve 1906",[45] but did not provide any additional details, and his comment was little noticed at the time.[46]
The first widely publicized information about Fessenden's early broadcasts did not appear until 1932, when an article prepared by former Fessenden associate Samuel M. Kintner, "Pittsburgh's Contributions to Radio", appeared in the December 1932 issue of The Proceedings of the Institute of Radio Engineers.
Anticipation of the 2006 centennial anniversary of Fessenden's reported broadcasts brought renewed interest, as well as additional questions. A key issue was why, despite Fessenden's assertion that the two programs had been widely heard, there did not appear to be any independent corroborating evidence for his account. (Even the Helen Fessenden biography relies exclusively on details contained in the January 29, 1932, letter used by the Kintner article.) There was general consensus in the centennial discussions that Fessenden had the technical means to make broadcasts, given the widespread reports about the success of the December 21 alternator-transmitter demonstrations. However, because of the station's very low power, even if the broadcasts had taken place it was questionable if the range could have matched Fessenden's claim of being heard hundreds of kilometers away.[citation needed]
In the period leading up to the centennial, James E. O'Neal conducted extensive research, but did not find any ships' radio log accounts, or any contemporary literature, to confirm the reported holiday broadcasts.
The American Telephone Journal account of the December 21 alternator-transmitter demonstration included the statement that "It is admirably adapted to the transmission of news, music, etc. as, owing to the fact that no wires are needed, simultaneous transmission to many subscribers can be effected as easily as to a few",[32] echoing the words of a handout distributed to the demonstration witnesses, which stated "[Radio] Telephony is admirably adapted for transmitting news, stock quotations, music, race reports, etc. simultaneously over a city, on account of the fact that no wires are needed and a single apparatus can distribute to ten thousand subscribers as easily as to a few. It is proposed to erect stations for this purpose in the large cities here and abroad."[55] However, other than the two reported holiday transmissions, Fessenden does not appear to have conducted any other radio broadcasts, or to have even given additional thought about the potential of a regular broadcast service. In a 1908 comprehensive review of "Wireless Telephony", he included a section titled "possibilities" that listed promising radio telephone uses. Neither the main article, nor this list, makes any reference to broadcasting, instead only noting conventional applications of point-to-point communication, enumerated as "local exchanges", "long-distance lines", "transmarine transmission", "wireless telephony from ship to ship", and "wireless telephone from ship to local exchange".[56]
Continuing work and dismissal from NESCO
The technical achievements made by Fessenden were not matched by financial success. Walker and Given continued to hope to sell NESCO to a larger company such as the
Later years
After Fessenden left NESCO, Ernst Alexanderson continued to work on alternator-transmitter development at General Electric, mostly for long range radiotelegraph use. He eventually developed the high-powered
Although Fessenden ceased radio research after his dismissal from NESCO in 1911, he continued to work in other fields. As early as 1904 he had helped engineer the
At the outbreak of
An inveterate tinkerer, Fessenden eventually became the holder of more than 500 patents. He could often be found in a river or lake, floating on his back, a cigar sticking out of his mouth and a hat pulled down over his eyes.[64] At home he liked to lie on the carpet, a cat on his chest. In this state of relaxation, Fessenden could imagine, invent and think his way to new ideas. Fessenden also had a reputation for being temperamental, although in his defense his wife later stated that "Fessenden was never a difficult man to W O R K with but he was an intensely difficult man to play politics with."[65] However, one of his former assistants, Charles J. Pannill, recalled that "He was a great character, of splendid physique, but what a temper!", while a second, Roy Weagant, ruefully noted that "He could be very nice at times, but only at times."[64]
In 1925, Radio News, saluting Fessenden as "one of the greatest American radio inventors", began a monthly autobiographical series titled "The Inventions of Reginald A. Fessenden", with the intention of publishing the completed installments as a book. However, instead of reviewing his radio work, Fessenden immediately went on a series of tangents, including discussions of which races he believed were the most capable of producing inventions, and the proper approach that government institutions should be taking in order to support inventors. (At the close of the seventh installment, Radio News included a disclaimer that it was "not responsible for any opinions expressed in Dr. Fessenden's article".)[66] After eleven installments Fessenden had only covered his life up to 1893, having discussed virtually nothing about radio, and the series was quietly terminated at this point.[67]
Awards
In 1921, the
Death and legacy
After settling his lawsuit with RCA, Fessenden purchased a small estate called "Wistowe" (previously the home of Charles Maxwell Allen, the United States Consul, who had hosted
It sometimes happens, even in science, that one man can be right against the world. Professor Fessenden was that man. It is ironic that among the hundreds of thousands of young radio engineers whose commonplaces of theory rest on what Professor Fessenden fought for bitterly and alone only a handful realize that the battle ever happened... It was he who insisted, against the stormy protests of every recognized authority, that what we now call radio was worked by "continuous waves" of the kind discovered by Hertz, sent through the ether by the transmitting station as light waves are sent out by a flame. Marconi and others insisted, instead, that what was happening was the so-called "whiplash effect"... It is probably not too much to say that the progress of radio was retarded a decade by this error... The whiplash theory faded gradually out of men's minds and was replaced by the continuous wave one with all too little credit to the man who had been right...[72]
Beginning in 1961, the Society of Exploration Geophysicists has annually awarded its Reginald Fessenden Award to "a person who has made a specific technical contribution to exploration geophysics".[73] In 1980, a Fessenden-Trott Scholarship was established at Purdue University's School of Electrical and Computer Engineering, in memory of Reginald Fessenden and his wife.[74]
Reginald A. Fessenden House
Fessenden's home at 45 Waban Hill Road in the village of Chestnut Hill in Newton, Massachusetts, is on the National Register of Historic Places and is also a U.S. National Historic Landmark. He bought the house in 1906 or earlier and owned it for the rest of his life.[citation needed]
See also
- Alexanderson alternator: used by Fessenden for his first radio broadcast.
- Fessenden oscillator
- List of Bishop's College School alumni
- Reginald Fessenden patents
- Sonar
References
Citations
- ^ a b " Reginald Fessenden U.S. passport application "Form for Native Citizen", dated August 26, 1914. The signed and notarized application stated that Fessenden was a "native and loyal citizen of the United States" who held U.S. birthright citizenship through his American-born father. In addition, although for his early U.S. patents Fessenden listed his citizenship as Canadian, in a majority of his subsequent applications he described himself as "a citizen of the United States".
- ^ "The Inventions of Reginald Fessenden: Part III", Radio News, March 1925, p. 1631.
- ^ In June 1878 Bishop's College School had an enrollment of 43 boys.
- ^ "The Inventions of Reginald Fessenden: Part V", Radio News, May 1925, pp. 2054–2056.
- ^ Total enrollment at Bishop's College for the school year 1883–84 was twenty-five students.
- ISBN 0921992238
- ^ a b "The Inventions of Reginald A. Fessenden: Part VI", Radio News, June 1925, pp. 2216–2218, 2274, 2276.
- ^ Marriage Certificate Number: 10666. Ancestry.com. New York, Extracted Marriage Index, 1866–1937 [database on-line]. Provo, Utah: Ancestry.com Operations, Inc., 2014. Original data: Index to New York City Marriages, 1866–1937.
- ISBN 0921992238
- ^ "The Inventions of Reginald A. Fessenden: Part VIII", Radio News, August 1925, pp. 156–158, 237.
- ^ "The Inventions of Reginald A. Fessenden: Part IX", Radio News, September 1925, pp. 276–277, 380–384.
- ^ "The Inventions of Reginald A. Fessenden: Part XI", Radio News, November 1925, pp. 590–591, 712–718.
- ^ Western University was renamed to the University of Pittsburgh in 1908.
- ^ The Continuous Wave by Hugh G. J. Aitken, 1985, p. 50.
- ^ Karwatka, D. (2004). "Reginald Fessenden and Radio Transmission". Tech Directions, March 2004, 63(8), 12.
- ^ "Electrolytic Detectors", Wireless Telegraph Construction For Amateurs by Alfred Powell Morgan, 1914, p. 118.
- ^ Aitken (1985) pp. 58–60.
- ^ This incident recalled F. O. J. Smith, a member of the House of Representatives from Maine, who had used his influence to gain a one-quarter interest in Samuel Morse's telegraph.
- ^ National Electric Signalling Company (advertisement), The Electrician, April 22, 1904, p. xxi.
- ^ Aitken (1985), p. 70.
- ^ "Some Interesting Radio History", Radio World, September 8, 1923, p. 21.
- ^ Fessenden, Helen (1940) pp. 124–126.
- ^ "Fall of a Wireless Telegraphy Tower in a Gale" by W. A. S. Douglas, Symons's Meteorological Magazine, December 1906, pp. 201–205.
- ^ "Trans-Atlantic Wireless Telegraphy", Engineering, Part I: January 18, 1907, p. 89; Part II: January 25, 1907, pp. 108–111.
- ^ "The Wireless Telegraph Situation" (correspondence from Reginald Fessenden), Scientific American, January 19, 1907, p. 70.
- ^ Aitken (1985) p. 72.
- ^ "Sine Form Curves of Alternating E. M. F." (letter from Reginald Fessenden), The Electrical World, September 15, 1894, p. 264.
- ^ Fessenden, Helen (1940), pp. 60–61, 76.
- ^ US 706737 patent: "Wireless Telegraphy", submitted May 29, 1901, and issued August 12, 1902, to Reginald Fessenden.
- ^ The Principles of Electric Wave Telegraphy by J. A. Fleming, 1906 edition, p. 511.
- ^ "Figure 9", "Experiments and Results in Wireless Telephony" (part II) by John Grant, The American Telephone Journal, February 2, 1907, p. 70.
- ^ a b c "Experiments and Results in Wireless Telephony" by John Grant, The American Telephone Journal. Part I: January 26, 1907, pp. 49–51; Part II: February 2, 1907, pp. 68–70, 79–80.
- ^ The Canadian Father of Radio Broadcasting – Toronto Star
- ^ Aitken (1985), p. 61.
- ^ Aitken (1985), p. 62.
- ^ Fessenden, Reginald A. "Inventing the Wireless Telephone and the Future". Ewh.ieee.org. Retrieved 2014-02-09.
- ^ "Wireless Telephony" by Reginald A. Fessenden, Transactions of the American Institute of Electrical Engineers, Vol. XXVII (1908), Part 1, pp. 553–629.
- ^ Aitken (1985), p. 69.
- ^ The Brant Rock rotary-spark transmitter was rated at 100,000 watts ("Some Interesting Radio History", Radio World, September 8, 1923, p. 21), while the alternator transmitter had an estimated output of 12 watts (Aitken (1985) p. 74).
- ^ "Recent Progress in Wireless Telephony" by Reginald A. Fessenden, Scientific American, January 19, 1907, pp. 68–69.
- ^ "Wireless Telephone Tests at Brant Rock and Plymouth, Mass." by Greenleaf W. Pickard, included as an appendix in Wireless Telephony in Theory and Practice by Ernst Ruhmer (translated from the German by James Erskine-Murray), 1908, pp. 205–214.
- ^ " The First Transatlantic Telephonic Transmission" (correspondence from Reginald Fessenden), Scientific American, September 7, 1918, p. 189.
- ^ Father of Radio by Lee de Forest, 1950, p. 225.
- ^ I Looked and I Listened by Ben Gross, 1954, p. 48.
- ^ "The Early History of Radio in the United States" by H. P. Davis, in The Radio Industry: The Story of its Development, 1928, p. 190.
- ^ "Fessenden's Christmas Eve Broadcast: Reconsidering An Historic Event", by Donna L. Halper and Christopher H. Sterling, The AWA Review, August 2006, p. 121.
- ^ "Pittsburgh's Contributions to Radio" by S. M. Kintner, Proceedings of the Institute of Radio Engineers, December 1932, pp. 1849–1862.
- ^ Fessenden, Helen (1940), pp. 153–154.
- ^ "Fessenden: World's First Broadcaster?". 25 October 2006. Archived from the original on January 18, 2017. Retrieved 2017-01-17.
{{cite web}}
: CS1 maint: bot: original URL status unknown (link) by James E. O'Neal, Radio World, October 25, 2006. (radioworld.com) - ^ "Fessenden – The Next Chapter". Archived from the original on July 3, 2015. Retrieved 2018-03-13.
{{cite web}}
: CS1 maint: bot: original URL status unknown (link) by James E. O'Neal, Radio World, December 23, 2008. (radioworld.com) - ^ Halper and Sterling (2006), page 129.
- ^ "Fessenden's Christmas Eve Broadcast – Revisited" by John S. (Jack) Belrose, 2007(?). (radiocom.net) Includes the full text of Fessenden's January 29, 1932, letter to Kintner.
- ^ "Milestones: First Wireless Radio Broadcast by Reginald A. Fessenden, 1906". IEEE Global History Network. IEEE. Retrieved 29 July 2011.
- ^ Lee de Forest: King of Radio, Television, and Film by Mike Adams, 2012, p. 101.
- ^ "Dec. 21, 1906: A Very Significant Date in Radio". 22 December 2016. Archived from the original on January 18, 2017. Retrieved 2017-01-17. by James E. O'Neal, December 22, 2016. (radioworld.com)
- ^ Fessenden, Reginald (1908), "Wireless Telephony", pp. 606–608.
- ^ Fessenden, Helen (1940), pp. 327–334.
- ^ "Continuous Wave Radio Communication" by D. G. Little, The Electric Journal, April 1921, p. 125.
- ^ Blake, R.F. (1914). "1914: Submarine Signaling; Submarine Signaling: The Protection of Shipping by a Wall of Sound and other Uses of the Submarine Telegraph Oscillator". National Oceanic and Atmospheric Administration, Transcription. Retrieved 17 March 2020.
- ^ Frost, Gary L. (July 1, 2001). "Inventing Schemes and Strategies: The Making and Selling of the Fessenden Oscillator". Retrieved 16 March 2020.
- . Retrieved 16 March 2020.
- ^ Jörg Schimmler (2013): Alexander Behm – Erfinder des Echolots. BoD (Books on Demand), Norderstedt. P. 31: Am 24. September 1912 reichte Behm sein Echolotkonzept auf der Grundlage der Intensitätsmessung mit seinem Sonometer in Österreich zum Patent ein. Das Echolot – zumindest von der Idee her – war geboren. Das Patent wurde nicht erteilt, da in Österreich eine Idee allein nicht patentfähig war. Patentierbar wäre nur die technische Ausführung gewesen. (rough translation: On September 24, 1912, Behm filed Sonar concept based on the intensity measurement with his sonometer in Austria for a patent. The echo sounder - at least in terms of the idea - was born. The patent was not granted because an idea alone was not patentable in Austria. Only the technical design would have been patentable.) In 1913, Behr successfully filed for a patent in Germany: He got Reichspatent DRP 282009 on 22 July 1913 (Schimmler, p. 47)
- ISBN 087169896X.
- ^ a b Radio's 100 Men of Science by Orrin E. Dunlap, 1944, pp. 139–140.
- ^ Fessenden, Helen (1940), p. 245.
- ^ "The Inventions of Reginald A. Fessenden: Part VII", Radio News, July 1925, p. 119.
- ^ Aitken (1985), p. 29 (footnote #2).
- ^ "IEEE Medal of Honor Recipients". IEEE. Retrieved April 13, 2021.
- . Retrieved March 30, 2011.
- ^ Fessenden, Helen (1940), pp. 302, 325–327.
- ^ "Flatts: The Small Town with a Big History: Wistowe & the Tidal Race", by Elizabeth Jones. The Bermudian magazine. The City of Hamilton, Bermuda. 5 November 2020.
- ^ Fessenden, Helen (1940), pp. 316–317. The editorial being quoted, "Fessenden Against the World", appeared on p. 14 of the July 29, 1932 New York Herald-Tribune.
- ^ Reginald Fessenden Award (formerly Medal Award) (SEG.org)
- ^ ECE Scholarships (engineering.purdue.edu)
General information
- Hugh G. J. Aitken, The Continuous Wave: Technology and American Radio, 1900–1932. Princeton University Press. Princeton, New Jersey. 1985.
- Ira Brodsky, "The History of Wireless: How Creative Minds Produced Technology for the Masses" (Telescope Books, 2008)
- Susan J. Douglas, Inventing American Broadcasting, 1899–1922. The Johns Hopkins University Press. Baltimore, Maryland. 1987.
- Orrin E. Dunlap, Jr., Radio's 100 Men of Science, Reginald Aubrey Fessenden entry, p. 137–141. Harper & Brothers Publishers. New York. 1944.
- Helen M. Fessenden, Fessenden: Builder of Tomorrows. Coward-McCann, Inc. New York. 1940.
- Reginald A. Fessenden, "The Inventions of Reginald A. Fessenden" Radio News, 11 part series beginning with the January 1925 issue.
- Reginald A. Fessenden, "Wireless Telephony," Transactions of the American Institute of Electrical Engineers, XXXVII (1908): 553–629.
- Gary L. Frost, "Inventing Schemes and Strategies: The Making and Selling of the Fessenden Oscillator," Technology and Culture 42, no. 3 (July 2001): 462–488.
- S. M. Kintner, "Pittsburgh's Contributions to Radio," Proceedings of the Institute of Radio Engineers, (December 1932): 1849–1862.
- David W. Kraeuter, "The U. S. Patents of Reginald A. Fessenden". Pittsburgh Antique Radio Society, Inc., Washington Pennsylvania. 1990. OCLC record 20785626.
- William M. McBride, "Strategic Determinism in Technology Selection: The Electric Battleship and U.S. Naval-Industrial Relations," Technology and Culture 33, no. 2 (April 1992): 248–277.
Patents
External links
- Reginald Aubrey Fessenden: Over a Century of Radio at the Wayback Machine (archived 2023-01-27)
- Belrose, John S. (September 5–7, 1995). "Fessenden and Marconi: Their Differing Technologies and Transatlantic Experiments During the First Decade of this Century". International Conference on 100 Years of Radio. Vol. 1995. pp. 32–43. ISBN 0852966490.
- Canadian Communications Foundation's "The Start of Radio Broadcasting" at the Wayback Machine (archived 2021-12-01)
- Belrose, John (April 2002). "Reginald Aubrey Fessenden and the Birth of Wireless Telephony" (PDF). IEEE Antennas and Propagation Magazine. Vol. 44, no. 2. Archived (PDF) from the original on 2010-12-26. Retrieved 29 October 2015.
- Seitz, Frederick (1999). "The Cosmic Inventor". Transactions of the American Philosophical Society.
- Smith, Brian (December 2000). "The Story of Reginald Aubrey Fessenden". On the shortwaves.com. Retrieved 15 February 2013.
- "George H. Clark Radioana Collection". National Museum of American History. Smithsonian Institution. 1880–1950.
- "The National Electric Signaling Co". New England Wireless and Steam Museum.
- "Christmas Eve and the Birth of 'Talk' Radio" – NPR at the Wayback Machine (archived 2022-12-31)
- Encyclopedia Americana. 1920. .