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Pre-War Vacuum-tube Transmitter Development (1914-1917)
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AT&T initially developed vacuum-tubes as amplifiers for long-distance telephone lines. However, this was only the beginning of the device's versatility, as various scientists and inventors would develop numerous innovations, including efficient continuous-wave transmitters, which would eventually replace the earlier spark, arc, and alternator varieties. Vacuum-tube transmitters were also used for an increasing number of broadcasting experiments, however these fledgling efforts came to an abrupt end on April 6, 1917, when the United States entered World War One. At that time, all radio stations not needed by the government were closed, and it became illegal, for the duration of the war, for the general population to listen to any radio transmissions, from any source.
Lee DeForest -- American Telephone and Telegraph Company -- Marconi -- Other Experimenters


In 1914, the first vacuum-tube radio transmitters began to appear, a key technical development which would lead to the introduction of widespread broadcasting. Both amateurs and commercial firms started to experiment with the new vacuum-tube transmitters, employing them for a variety of purposes. One of the first persons to adopt the new technology was Lee DeForest. Six years after suspending his efforts to make audio transmissions, when he had unsuccessfully tried to use arc-transmitters, DeForest again took up developing radio to transmit sounds, including broadcasting news and entertainment, this time with much more success. (In retrospect, DeForest recognized the irony that he had overlooked the potential of developing his Audion as a radio transmitter. Reviewing his earlier arc-transmitter efforts, he wrote in his autobiography that he had been "totally unaware of the fact that in the little audion tube, which I was then using only as a radio detector, lay dormant the principle of oscillation which, had I but realized it, would have caused me to unceremoniously dump into the ash can all of the fine arc mechanisms which I had ever constructed, a procedure which a few years later actually took place all over the world!") For The Railroad Men, from the April 26, 1914, Elmira Telegram, and Radiotelephony For Railroads, from the May 30, 1914 Electrical World, reported on tests conducted by the DeForest Radio Telephone & Telegraph Company on a Delaware, Lackawanna & Western Railroad train, designed for internal company communication, while High-Frequency Oscillating Transmitter for Wireless Telephony from the July 18, 1914 Electrical World reviewed a DeForest transmitter with which "it is possible to telephone one to three miles, and the device is well adapted for use on small yachts, tugs, ferryboats, etc."

DeForest later expanded into public broadcasts, from his experimental radio station, 2XG, located in the Highbridge section of New York City. Columbia Used to Demonstrate Wireless, in the November 4, 1916 issue of The Music Trade Review, reported on an October 26th demonstration broadcast, where DeForest transmitted selections from Columbia phonograph records, while noting that regular transmissions would begin shortly. The November 6, 1916 New York Sun reported that the Air Will be Full of Music To-night, as DeForest inaugurated nightly half-hour broadcasts, featuring "the leading news of the day", according to a report appearing in numerous newspapers, including Wireless Newspaper Wafted Out To Sea in the November 7, 1916 New York Tribune. November 7th was an election day, featuring a Presidential contest in which incumbent Woodrow Wilson would prevail over Charles Evans Hughes. The New York American provided election returns to the DeForest station for that night's broadcast, and accounts in that newspaper reported that 2XG had successfully "shot thousands of waves laden with the news of the election", and "For the first time the wireless telephone has been demonstrated as a practical, serviceable carrier of election news and comment." Returns by Wireless from the November 8, 1916 New York Times and Election Returns Flashed by Radio to 7,000 Amateurs, in the January, 1917 issue of The Electrical Experimenter, further documented the success of the special broadcast. Other station reviews included Wireless Transmission of News, which appeared in the December 30, 1916 issue of Telephony, and declared the broadcasts to be "a remarkable step forward in the distribution of the world's news and music", and Dance to Wireless Music 40 Miles Off from the December 31, 1916, New York Times. Beginning in early 1917, QST magazine carried a series of reports about 2XG's nightly broadcasts -- included in these Highbridge station reports was speculation by QST about the possibilities of using radio for advertising. The February 18, 1917 Brooklyn Eagle reported that, thanks to the weekday evening broadcasts, local resident Eben J. Homan Has Concerts at Home By Wireless Telephone, where his guests "have been unanimous in pronouncing the entertainment delightful". However, the April 7th closure of civilian radio stations, caused by the entrance of the United States into World War One, brought these ground breaking broadcasts to an end.


In late 1914, AT&T began negotiations with Lee DeForest, which led to their purchase of the commercial rights to his radio patents. The company soon began a series of test radiotelephone transmissions over increasing distances. In June, 1915 AT&T and its Western Electric subsidiary installed a powerful experimental vacuum-tube transmitter at NAA, the U.S. Navy station located in Arlington, Virginia, across the Potomac River from the U.S. capital, which soon achieved remarkable distances for its audio transmissions, as reported by Wireless Telephony Now From Washington to Honolulu, in the November, 1915 issue of The Electrical Experimenter, and By Wireless 'Phone from Arlington to Paris, which appeared in the next month's issue. The experimentation, involving hundreds of workers led by AT&T chief engineer John J. Carty, was a "triumph of intelligent team work", according to Arthur Benington's Team Work Made Wireless Telephony Possible, from the November 28, 1915 Fort Wayne Journal-Gazette. On November 27th, NAA was employed to make the First Public Wireless Demonstration, as a gathering in New York City heard the Star Spangled Banner and conversation transmitted from Washington, D.C., as reported by the December, 1915 Bell Telephone News. The successful transmissions led to interest by the U.S. Navy for their own communication needs, according to Fleet Tests Radio Phone from the January 31, 1916 New York Times. The tests at NAA marked the beginning of a ten-year period of increasing AT&T prominence within the U.S. radio industry, and also led Paul Calhoun to ask Why Not Have the President Talk Simultaneously to "All the People?" in the September, 1916 issue of The Electrical Experimenter.


The Marconi companies joined those experimenting with the new vacuum-tube transmitters, and in the September 5, 1914 Electrical World, Wireless Telephone Set announced that "A radio-telephone set which is designed for an oversea working range of 50 km (31 miles) between ship aerials 100 ft. high and having 200-ft. spans is being placed on the market by the Marconi Wireless Telegraph Company". In the April, 1915 issue of The Wireless Age, Marconi's Wireless Telephone was a further report on the low-powered vacuum-tube transmitter, while a test transmission, from the American Marconi plant at Aldine, New Jersey to David Sarnoff aboard the Bunker Hill off the coast of New York, was reported in Waft Music Into Air By Wireless from the June 12, 1916 New York Times and Marconi Wireless Telephone from the August, 1916 QST. Although the details are somewhat murky, there is evidence that Sarnoff -- at the time a mid-level American Marconi employee in New York City, but who, thirteen years later, would become the third president of the Radio Corporation of America -- was particularly influenced by DeForest's groundbreaking broadcasts in 1916. Sarnoff's famous "Radio Music Box" memo, circa November, 1916 -- there is some uncertainty about the date -- reviewed the possibilities of his company setting up a radio broadcast service aimed at the general public. Sarnoff's memo didn't mention DeForest, however, one of Sarnoff's biographers, Carl Dreher in An American Success, believed that the 2XG broadcasts were its main inspiration. Assuming the "Radio Music Box" memo actually does date to November, 1916, it is probably fortunate that the Marconi management didn't try to start up a broadcast service at that time, as just five months later the new service would have been shut down, due to the advent of World War One.


Although DeForest's experimental broadcasts are the best known, other experimenters, not as well publicized, were also on the air using vacuum-tube transmitters. One startled operator was heard to exclaim "Holy hookfish!" upon first hearing the ship-to-shore exploits of Irving Vermilya, as recounted in Youthful Inventor of Wireless Telephone Tells of Achievement, from the March 15, 1914, New York Press. In 1915 Harold Power founded the American Radio and Research Corporation (AMRAD) in Medford Hillside, Massachusetts, which also began broadcasting over its experimental station, 1XE. On March 18, 1916, Power transmitted a widely heard musical concert, intended to impress financier J. P. Morgan, Jr. aboard the S.S. Philadelphia, which was reported by Music Sent By The Wireless in the March 27, 1916 Boston Globe. Later reports included Wireless Achievements at Tufts College in Massachusetts, which appeared in the April 16, 1916 Electrical Review and Western Electrician, and Wireless Facts and Purposes from the Spring 1916 edition of Tufts College Graduate, while an extract from Doty Hobart's Came the Dawn of Broadcasting, from the August, 1930 Radio Digest, gives a broader history of this groundbreaking station.

In the June, 1916 issue of The Electrical Experimenter, Albert Marple reported that "there is a new 'fad' in Southern California", as Earl C. Hanson transmitted entertainment to his neighbors in Wireless Music With Your Meals. Music By Wireless from the August, 1917 The Electrical Experimenter reported that a shipboard concert on a vessel traveling from Hawaii to Russia had been heard by listeners in a wide radius of the Pacific Ocean.

A reporter reminisced, in Says George Cannon of New Rochelle First to Broadcast By Radio from the April 6, 1922 The Daily Argus, about witnessing an experimental broadcast in late November, 1916 over Special Amateur station 2ZK. And in a letter printed in Radio Broadcast's November, 1924 What Our Readers Write Us column, Cannon reported that from December, 1916 to February, 1917 he had maintained "a regular schedule from 9:30 p.m. to 10:30 p.m." of broadcasts of news and entertainment.

"Meanwhile, demonstrations had been given to officers of the United States Navy, including Captain (later Rear Admiral) W. H. G. Bullard. It was the generous coõperation of such open-minded officials as Bullard and Colonel Reber, a personal friend of Carty, that later made it possible to attempt the more pretentious program of transmitting speech across the Atlantic. But in the early stages of his contact with these Bell System engineers, Bullard was far from being enthusiastic. Writes R. A. Heising, in his reminiscences: 'Captain Bullard told me late that year that he had no faith in our being able to talk across the Atlantic when the subject was first broached to him. He felt it was the idea of people who knew nothing of radio. He didn't expect telephone people, of all people, to be able to do it. It was only the fact that the engineers who approached him had unquestioned reputations in the engineering world that prevented him from throwing them out and dismissing the proposal from his mind. He therefore listened politely to what they had to say, and witnessed the tests without being convinced. They seemed to be so enthusiastic about the project, however, that he finally thought that as it was their own money they wanted to spend, they should be given whatever opportunity there was, and he would look into the matter further.'"--"Pioneering in Radio Telephony", Bell Telephone Magazine, February, 1941.