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UNITED STATES EARLY RADIO HISTORY
THOMAS H. WHITE | |
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Arc-Transmitter Development (1904-1921)
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A more compact -- although not quite as refined -- method for generating continuous-wave radio signals was the arc-transmitter, initially developed by Danish inventor Valdemar Poulsen. Because arc-transmitters were less complicated than alternator-transmitters, a majority of the early experimental audio transmissions would use this device. VALDEMAR POULSEN Due to their size, complexity and cost, alternator-transmitters were mostly employed for longrange radiotelegraphy, and rarely used for audio transmissions. But another developing continuous-wave technology also showed promise -- the arc-transmitter, which had been perfected beginning in 1902 by Valdemar Poulsen of Denmark. At the 1904 Saint Louis International Electrical Congress, Poulsen submitted a paper reviewing his discoveries, System for Producing Continuous Electric Oscillations, and expressed the hope that this new transmitting system would soon be used for "syntonic wireless telegraphy and telephony". Another Selective Wireless, which appeared in the July, 1906 Electrician and Mechanic, reported on Poulsen's on-going progress, followed by a more detailed review, The Poulsen Wireless Station at Lyngby, from the June, 1908 issue of Modern Electrics. (In addition to his radio inventions, Poulsen was also well known for developing a wire "Telegraphone" sound recording device, reviewed by E. F. Hearns in A Spool of Wire Speaks from the December, 1906 Technical World Magazine). Meanwhile, Wireless Telephony, in the December 8, 1906 Electrical World, reprinted a report from the November 15, 1906 Elektrotechnische Zeitschrift that German experimenter Ernst Ruhmer had successfully employed Poulsen's invention to transmit speech across a laboratory room, which "makes wireless telephony at once possible". LEE DEFOREST One person attending the Saint Louis conference, Lee DeForest, was particularly impressed by Poulsen's invention, and would spend many years trying to develop arc-transmitters for audio transmissions, both for point-to-point communication and for broadcasting entertainment and news. Forced out of United Wireless in late 1906, DeForest formed the Radio Telephone Company, to promote "sparkless" arc-based transmission systems. But although DeForest made a number of well publicized experimental and publicity transmissions, he was ultimately unsuccessful in developing a reliable arc system. (A major problem likely was the fact that he never got around to purchasing the rights to use Poulsen's patents, which seems to have led to some hit-or-miss engineering work. In his autobiography, DeForest claimed, not very convincingly, that he had read that another inventor had anticipated Poulsen's development of the hydrogen arc, which meant it was all right for him to use it). According to his autobiography, on December 31, 1906 DeForest was able for the first time to transmit his voice across a room. He then moved rapidly, and prematurely, to develop commercial sales. Reporting Yacht Races by Wireless Telephony from the August 10, 1907 Electrical World boasted that "The first actual application of radio-telephony to practical work anywhere in the world was made at Put-in-Bay, in Lake Erie, during the week of July 15 to 20, in reporting the regatta of the Interlake Association." DeForest next promoted his system to the U.S. Navy, and in the October 12, 1907 issue of The Outlook, Wireless Telephones at Sea reported initial tests being conducted on the Connecticut and Virginia using his equipment, which included the broadcasts of phongraph records from the Connecticut for the amusement of the other vessels. These tests were impressive enough for the Navy to have DeForest supply its "Great White Fleet" with 26 arc radiotelephones for an around-the-world voyage, and this innovation merited articles in two 1908 issues of Telephony magazine: Wireless Telephony in the Navy, by N. J. Quirk, appearing in January, and Wireless Telephony for the Navy, by Herbert T. Wade, which ran in May. Franklin Matthews' 1908 book, "With the Battle Fleet", included his first-hand impressions of the Fleet's Wireless Telephones, noting that although the innovation was "largely in the experimental and almost the infantile stage", naval electricians "were confident that as soon as certain difficulties were overcome, difficulties no more serious, they said, than the ordinary telephone encountered in the beginning, the apparatus would be workable as readily as a telephone on land." However, at this early stage the transmitters proved impracticable, and were scraped at the end of the voyage, evidenced by reports such as Wireless Telephone On Battle Fleet a Total Failure from the August, 1909 Popular Mechanics. In The Radiotelephone Failure section of Linwood S. Howeth's 1963 History of Communications-Electronics in the United States Navy, the author wrote: "One of the first mistakes of the [USN Radio Division head Lt. Comdr. Cleland] Davis regime was that of becoming too quickly convinced of the capabilities and promises of the radiotelephone equipment by De Forest in the summer of 1907. Under ordinary circumstances De Forest equipment was noted for its lack of engineering design and perfection and under such hurried procurement the equipment delivered was far below this normal low quality." DeForest was one of the first persons to suggest using radio signals to broadcast entertainment to a wide audience, and in the June, 1907 issue of The American Monthly Review of Reviews, Herbert T. Wade's Wireless Telephony by the De Forest System noted the possibilities for "the distribution of music from a central station", and also reported that "the inventor believes that by using four different forms of wave as many classes of music can be sent out as desired by the different subscribers". However, DeForest was also known for being excessively optimistic, as this review also reported, very prematurely, that "Dr. De Forest has reached the conclusion that wireless telephony on a practical and commercial scale has been realized." Wireless Telephony at Last from the June 15, 1907 The Literary Digest further reviewed radio-telephone systems developed by DeForest, and by Adolphus Slaby in Germany. Barnard Girls Test Wireless 'Phones, from the February 26, 1909 New York Times, reported on a test where Mrs. Stanton Blatch, DeForest's mother-in-law, used the new technology to promote the then-controversial idea that women should be allowed to vote. DeForest's later entertainment broadcasting efforts included an opera, direct from the Metropolitan Opera House in New York City, reviewed in Grand Opera by Wireless, in the March 5, 1910 issue of Telephony, plus a concert by Mme. Mariette Mazarin, reported by Radio Telephone Experiments in the May, 1910 issue of Modern Electrics. However, the Mazarin concert was the final effort for many years for his broadcasting experiments -- the technology for quality audio transmissions just did not exist yet. It wouldn't be until 1916, following the development of vacuum-tube transmitters, that DeForest would return to exploring radio for news and entertainment broadcasts. In addition, the company's attempt to set up a point-to-point radiotelephone service along the Great Lakes also collapsed at this time, as reported in a short note appearing in the August 6, 1910 issue of Telephony: Great Lakes Wireless Telephone Out of Business. These financial and technical problems, plus legal troubles, caused DeForest to suspend his development of arc-transmitters for audio transmissions. ADDITIONAL EARLY EXPERIMENTERS Numerous companies on both sides of the Atlantic and in Japan tried developing arc-transmitters for audio transmissions, and over the years, Poulsen licenced the rights to his arc-transmitter patents to a variety of firms, some more successfully than others. The November 22, 1906 New York Times carried a short announcement, Backs Wireless Invention, that a Lord Armstrong in Great Britain had purchased the U.S. rights for $500,000. Over the next two years, the Times carried a series of announcements proclaiming important European advances, including Wireless Over Atlantic on July 28, 1907, which foresaw the imminent establishment of a trans-Atlantic radiotelegraph service, followed by December 20, 1907's Poulson Confident of Oversea 'Phone, and Pictures By Wireless from January 1, 1908, which added radiotelephone and facsimile services to the projected trans-Atlantic service -- which would never actually be established -- while Voice Will Carry Across the Sea from January 12, 1908, suggested that Poulsen's success in holding a two-way voice conversation over 250 miles (400 kilometers) would soon be translated into a commercial service. A. Frederick Collins also developed an arc-transmitter system, which was reviewed in The Collins System of Long-Distance Wireless Telephony in the September 19, 1908 Scientific American, and in greater detail by William Dubilier's Wireless Telephony chapter in the 1909 book Wireless Telegraphy and High Frequency Electricity. However, none of these promotions actually had the financial stability or technical refinement needed to succeed. For eighteen months in 1908-1909, equipment designed by a German company, Telefunken, was evaluated by the U.S. Army Signal Corps in New York Harbor -- in Experiences in Wireless Telephoning, from the April, 1912 Electrician and Mechanic, Austin C. Lescarboura reported that "the practicability of the wireless telephone was found to be uncertain". FEDERAL TELEGRAPH COMPANY Finally, in 1909 the U.S. rights to Poulsen's arc-transmitter were purchased by a syndicate backing Australian-born Cyril F. Elwell, who became Chief Engineer of a company set up in San Francisco, California, which soon became the Federal Telegraph Company. The company quietly prospered, and went on to produce progressively more powerful and sophisticated arc-transmitters for radiotelegraph use. (While Federal Telegraph successfully used arc-transmitters for longrange point-to-point radiotelegraph transmissions, it apparently never tried to develop audio transmissions.) An article by Elwell in the April 2, 1910 issue of the Journal of Electricity, Power and Gas, The Poulsen System of Wireless Telephony and Telegraphy, appeared shortly after the new company was founded. (Although the arc-transmitter worked well, the automated high-speed telegraphing equipment reviewed in Elwell's article still needed some work, according to Charles V. Logwood's High Speed Radio Telegraphy, from the June, 1916 issue of The Electrical Experimenter.) Wireless Across the U.S. by E. A. Mayne, from the May, 1911 Modern Electrics, reported the successful introduction of an overland radiotelegraph service, crossing the desert and Rocky Mountains between San Francisco, California and El Paso, Texas. Some Recent Developments of the Poulsen System of Wireless Telegraphy, by "W. C. R." from the July, 1912 Electrician and Mechanic, contrasted the less successful attempts to develop the Poulsen system in Europe and Canada with the recent advances of the Federal Telegraph Company. During World War One, the U.S. Navy purchased all of the Federal Telegraph stations, only to have the U.S. Congress instruct the Navy to return the stations to their original owners after the war ended. So, to its surprise Federal Telegraph found itself back in the radiotelegraph business, and the company's reorganization and expansion plans were explained by Acting Chief Engineer Haraden Pratt in New Stations of the Federal Tel. Co., from the February, 1921 Pacific Radio News. UNITED STATES NAVY In 1912, the U.S. Navy constructed a new station, NAA in Arlington, Virginia, as the first in a chain of high-power international links. This station initially used a 100 kilowatt NESCO rotary-spark transmitter designed by Reginald Fessenden. However, as recounted in The Federal Telegraph Co. of California and the Poulsen Arc Transmitter and The Radio (Arlington), Virginia, Station sections of Linwood S. Howeth's 1963 History of Communications-Electronics in the United States Navy, Elwell convinced the Navy to grudgingly let Federal Telegraph install a 35 kilowatt arc transmitter for comparison trials. The Navy was amazed to find that the compact arc transmitter outperformed the rotary-spark set, even though it was using just 1/3rd the power. At this point the Navy made an abrupt shift in its policies, and made increasingly powerful Federal Telegraph arcs the predominant transmitters in its new installations, as described in the Development of the High-Powered Chain chapter of Howeth's book. (Ironically, in a comprehensive paper on continuous-wave transmitters presented before the American Institute of Electrical Engineers in 1908, Fessenden had dismissed Poulsen's approach as an inefficient step backward from earlier researchers, worth mentioning in passing only "on account of the interest it appears to have excited in Europe"). In 1913, Cyril Elwell left Federal Telegraph, and Leonard Fuller became the company's new Chief Engineer. But Elwell continued to work as an Poulsen arc-transmitter designer on both sides of the Atlantic, and an article which appeared in the September 6, 1919 Electrical Review, Developments of Poulsen Wireless System Shown reviewed Elwell's radiotelegraph station engineering work for the period from 1909 through 1919. OTHER DEVELOPERS: HERROLD AND MARCONI On the west coast, Charles D. Herrold in San Jose, California did extensive experimental work with high-frequency spark and arc systems, and even broadcast entertainment programs on a regular schedule. A short review of his work by Milton E. Hymes, Correspondence, appeared in the November, 1913 The Electrical Experimenter, reported that the transmission of the song "The Trail of the Lonesome Pine" had been heard 900 miles (1,450 kilometers) away. In the April, 1914 issue of the same magazine, University of California Doing Good Radio Work reviewed additional radio-telegraph and radio-telephone activities. Marconi Wireless also did some limited development of arc transmitters in the United States, as the June 1914 issue of The Wireless Age reported on a test transmission from the Wanamaker's store station in New York to Philadelphia by Wireless Telephone. The next year the company, somewhat belatedly, purchased the English rights to use the Poulsen patents, announced in Marconi Absorbs Rival from the September 15, 1915 New York Times. However, although arc-transmitters were a significant advance over spark transmitters, they still were somewhat complicated, generally limited to radiotelegraphy, and would soon be supplanted by the development of vacuum-tube transmitters, which were even more efficient and reliable. (In his 1922 book Amateur Radio, Maurice J. Grainger, writing about the superiority of vacuum-tube transmitters for broadcasting purposes, wrote "Certainly an arc transmitter could be used, but the sounds that would be projected though the air by this means would be so inextricably mixed up with 'clicks, hisses, gurgles and howls' that nobody would have the patience to listen to it.") |
| "In 1903, Poulsen raised the arc to the status of a practically operative generator of radio frequency energy in considerable quantity by the following changes: placing the entire arc in an atmosphere of hydrogen or a hydrocarbon vapor (e.g., alcohol or gasoline), using a carbon electrode for the negative side and a copper anode water-cooled for the positive side, rotating the carbon electrode slowly by motor drive, and placing an intense deflecting magnetic field transverse to the arc. Except for certain constructional and electrical details, this is the Poulsen arc of to-day."--Alfred N. Goldsmith, Radio Telephony, 1918. |