|
| |
Radio Technology: From Amateurs to Inventors
From: Columbia University
| By:
|
EDITOR'S INTRODUCTION |
Even in today's Internet age, radio remains a part of everyday life. While its technology predates the current electronic era, its  inception and dissemination follow a pattern starkly similar to today's amateur and professional practices in computing.
In the early years of the twentieth century, amateur radio operators, better known as "hams," began dabbling in radio technology, experimenting with Morse code and recreational communication. They have been likened to pre-computer-age hackers. Some hams went on to successful careers in radio and radiotelephony, as inventors, engineers and editors.
In the following excerpts from interviews conducted by Columbia University's Oral History Research Office for its "Radio Pioneers" project, two amateurs-turned-professionals, Lloyd Espenschied and Ernst Alexanderson, tell Frank Ernest Hill and C. D. Wagoner their respective stories about their early experiences with radio. |
Lloyd Espenschied<br> Introduction to broadcasting
Broadcasting arose not at any one time, from any one person, but gradually over the years as an integral part of the development of radiotelephony. As it became possible to transmit speech and music by wireless, broadcasting naturally followed by virtue of the natural spreading of radio waves in all directions. It has been my good fortune to have lived through the entire period, in close association with the appearance of radiotelephony, as distinct from radiotelegraphy, and in turn, broadcasting. |
Amateur days
By 1904, I had become interested in wireless telegraphy while in Boys High School in Brooklyn. It was the intriguing apparatus in the Physics Lecture Hall, the several types of vacuum tubes, the so-called Geissler tubes, the Crooks tubes (actually originated by Hittorf, I find) and the X-ray tubes, plus the big fat Ruhmkorff coil for driving these tubes. All this plus an after-hour boyish activity in the Electrical Club of the high school, in which boys brought in their own apparatus and operated it, including wireless telegraph instruments. |
By 1905, I was head over heels an amateur constructor and experimenter in this newly budding field of wireless. There were half a dozen boys in the vicinity who shared my interest, and we constituted a local amateur group, making our own apparatus, learning the telegraph code and operating wireless telegraphy. We connected ourselves together by a wire telegraph line, to be more sure of reaching each other, which extended about a mile in the neighborhood and connected with the Children's Museum. One of my pals, Austin M. Curtis, and I were written up and pictured in the New York Herald, Sunday edition, of January 7, 1906, under the caption "School Boys Aim at Rivaling Marconi." |
My interest in wireless, as an amateur constructor and operator, became so great that I sacrificed my high-school studies in my final year before graduation, and before I really realized what I was doing I was on a seagoing ship as a wireless telegraph operator, employed by the United Wireless Telegraph Co. This was in May 1907. By the fall of 1907, some of the romance had rubbed off, and I realized I needed more education. I went back to school, now to Pratt Institute in Brooklyn, taking there the course in applied electricity. The following summer, 1908, I again went to sea as a wireless operator. My second year at Pratt, I was permitted to follow my interest by making and testing wireless apparatus as part of the curriculum. |
Upon graduating from Pratt in 1909 (it was only a two-year course), I joined Jack Hogan at Westhaven, Connecticut, where he was living with his mother, studying and experimenting with radio, preparatory to attending the Yale Scheffield Scientific School that fall. As we parted that fall, I on my part took a job offered to me by the American License Co., of the Germans, namely the Telefunken Wireless Telegraph Co., of 111 Broadway, New York City. It did a business of importing wireless telegraph apparatus from Germany, largely for the army and the navy, the best known to the art; and at that time it was a new type of wireless telegraph system, that of the quenched, or singing-spark, type. I started with that company as assistant engineer, did some minor design work, but mainly testing, installing, delivering and demonstrating the equipment to the military. I was not content with this kind of work, which involved no real originating or development work, nor with the atmosphere of the company, so I left Telefunken in the fall of 1910. |
First years with the Telephone Company
In October 1910, I called on the chief engineer of the AT&T Co., J. J. Carty, thanks to a note of introduction from the New York editor of the Chicago electrical periodical, namely the Electrical Review, a Mr. Price. Carty received me most democratically, said that they in the telephone company had no wireless work, but that they might be able to use me, and offered me a job, which forthwith I took. Afterwards I realized that Carty was looking forward to the time when the company might be interested in developing radiotelephony. |
My first job was in the design of loading coils and small transformers for long-distance lines, a good experience. I was encouraged to follow radio developments "on the side." There was one other young fellow similarly following radio developments and actually maintaining a card catalog and reporting upon developments from time to time, namely, Robert Gowan. Soon thereafter he left the company, and it fell to me to be this technical reporter and catalyst, as it were, on wireless. So I came into a good position to keep informed and to make my optimism felt up the line. |
The Telephone Company's entry into radio
Claims and the evidence of progress manifested and posed a challenge to chief engineer Carty. He arose to it. He realized that no one yet knew how to accomplish telephony across the Atlantic but figured that if and when it was done it should be from the American side and especially by the AT&T Company. |
There was a scramble at AT&T and at W.E. Co. [Western Electric] headquarters for information on wireless, and naturally I was in my element. The principal unsolved problem of radiotelephony was that of how to control or modulate the high-frequency power required for long distances, by means of the weak voice currents. This project of wireless telephony continued under active study during 1914, at first on the assumption that an alternator or powerful arc would be required for transmitting, such as were being used for transoceanic wireless telegraphy. |
There was investigated the matter of duplex transmission for attaining two-way telephony, and schemes were devised for linking up with telephone lines, where by through speech may be had between telephone lines and radio links. Little did we then realize the luck into which we were to play, the birth of an entirely new and revolutionary technology that was to solve the problem of radiotelephony, of high-frequency multiplex telephony on wires, and of long-distance telephony in general, namely electronics. |
Attainment of the high-vacuum tube
It was that year, 1913, that there was attained in useful form the first high-vacuum tube in the Telephone Company's laboratories of the Western Electric Co. Almost simultaneously, the same sort of thing was being done in the General Electric laboratories at Schenectady, General Electric Co. having learned of DeForest's audion [vacuum tube] likewise late in 1912 through Alexanderson. There ensued a long contest in the Patent Office, after AT&T Co. found that the General Electric Co. had regarded Langmuir's contribution as an invention and filed a patent application. The position of the AT&T Co. was that this was not an invention but the application of scientific knowledge. But to combat Langmuir's patent application, [AT&T] had to file a patent application of its own, with fingers crossed, as it were. |
After long interference proceedings in the Patent Office, [AT&T] lost out and the Langmuir patent was issued. It was only later, when the G.E. Co. brought suit against the DeForest Radio Telephone Co., that the case of [AT&T] was more fully presented, went eventually to the Supreme Court, resulting in the overthrow of the Langmuir claim. This contest was of first-rate importance, for the high-vacuum tube made all the difference in the world between a fickle and really unserviceable vacuum tube and one which was reproducible, reliable and could eventually be made to carry relatively high power. It was upon the high-vacuum tube that radiotelephony evolved to success and in turn into broadcasting. |
Transoceanic radiotelephony realized, 1915
Through intense research and development in the laboratory, it became possible to demonstrate the new form of radiotelephony, first on a moderate power basis from a station erected for the purpose on Montauk Point, Long Island, transmitting to Wilmington, Delaware, and then St. Simons Island, Georgia--in both cases linking up with wire lines. I represented the company at Montauk Point and also at St. Simons Island in the course of these tests. Carty then "took the bit in his mouth" and undertook what we first thought could not be accomplished. He arranged with the navy for the use of the Arlington great antenna, at Arlington, just outside of Washington. It was to be used for transmitting by means of a new powerful radiotelephone transmitter to be installed at the base in a temporary building. He arranged again with the navy to enable his engineers to go to distant naval establishments and do the receiving in a grand experiment for extending speech for the first time across the continent and across the seas. |
He arranged with the French government to enable our engineers to go there, even though the European war was on, and attempt to receive the speech from Arlington. It was only by dint of hard work and good luck that the necessary number of power tubes were produced and operated for the transmitter. And fortunately, also, a new improvement in the receiving homodyne came just in time to enable this great experiment to succeed by the fall of 1915. I myself did the receiving at Pearl Harbor, Hawaii. My associates Bill Wilson and Hartley did the receiving at Mare Island, California. Harry Wilson did the receiving at Darien, Canal Zone, and Shreeve, and my old pal Curtis succeeded at the Eiffel Tower, despite all the noises surrounding the war, finally, in discerning the speech from Arlington. Carty thought of this as a great experiment in point-to-point telephony. Actually, it was also a great experiment in broadcasting. |
Whither radiotelephony?
The 1915 transoceanic experiments, coming on top of the opening of the transcontinental wire telephone service, reflected great credit upon the Bell system, to be sure. But perhaps too much? Would the public get the impression that radio was about to replace wires, leading the stockholders to sell their AT&T stock? This specter caused the telephone officials concern and led them to be ultra-cautious in predicting the future of the new art, a future which could only be determined by actual trial. |
One obvious field was communicating with ships at sea, and out-of-the-way places, where wires could not be used, and this was obviously a safe objective for the Telephone Company to pursue. This was done at first in connection with the navy, as a preparedness measure, World War I having already started in Europe, and in 1916, multiplex telephony at relatively short distances was demonstrated between two battleships. There was also a small program pursued in developing radiotelephone sets for miscellaneous use, but this got nowhere before the entry of the United States into the war in 1917. |
AT&T undertakes toll broadcasting, 1922
To explain how the Telephone Company became convinced that it should undertake broadcasting (after it had originated in a rather spontaneous way in experimenting with amateurs, as we have seen), I shall have to give some more personal testimony. Radiotelephony having been closely associated with the wire network in the Telephone Company's mind, and also in my own mind as an employee, as broadcasting hove in sight, I said to myself, "How can this sort of thing develop into a continuing service, how can it be supported financially?" I naturally resorted to wires, in my own mind, since the control they afford would enable a subscription type of service to be given, whereas in radio there was no control of the receiving end. Thus it was that I started rather bombarding my superiors with suggestions, starting with a form of wire broadcasting, and here I list the records of these suggestions: |
1919, December 18, a memorandum proposing broadcasting by carrier transmission over the lines of a power-distributing network: "By using channels of different frequencies, different classes of aural amusement would be simultaneously transmitted, permitting the subscriber to select at will his own type of amusement merely by pressing the proper button, which controls the selective circuit employed ... The amusement might come from stored sources as from phonograph devices, or it might be given directly by speaker or a concert." |
1920, May 7, a memorandum on the same subject, but now emphasizing carrier on telephone circuits for a network distribution system, with illustrated sketches. A demand for such service was seen in the "recent phenomenal expansion of the musical and phonograph industries." New and "powerful instrumentalities put an entirely new and promising complexion on the general distribution problem." |
1920, July 24, a memorandum on "a portable loud speaking radiotelephone receiver," calling attention to the rapid growth of broadcast by news and amusement, and wondering "whether radio may not be in this respect another phonograph or movie development." |
1921, January 17, a memorandum by one of my associates, Ralph Brown, on the "Radio Transmission Engineering of the Broadcasting Program," pointing out that in any broadcasting enterprise of this company, the transmission performance and standards must be the best attainable, and the need for doing some developmental work (showing continued interest on the part of us engineers in broadcasting). |
1921, March 21, a letter by my immediate superior, Blackwell, transmitting the two above-noted broadcast proposals to patent attorney Mr. Folk. My original draft of this letter of transmittal was too enthusiastic for Blackwell, so he quieted it down by saying, "It would seem that the American people could get along fairly well without attempting to force news and amusement upon them in an even more direct manner." This reflects the lack of appreciation on the part of the bosses of the remarkable prospects ahead. These wire-broadcast proposals became the subject of my US Patent 1666382, filed 1922, January 25, issued in 1927, which covered broadly network broadcasting. |
1921, July 14, a memo by me pointing out that radiotelephone broadcasting bids fair to be such an important matter "as to warrant a careful consideration of its possibilities from a business standpoint," and bringing out the importance of wire-line connections. |
1921, September 19, the above memo was transmitted by my superior, Blackwell, to Mr. Griswold, who had been brought in to handle the commercial and public relations end of the burgeoning new art of electronics, and transmitted also to the patent attorney, Folk. By this time, the telephone executives were really getting interested in the broadcasting craze and wondering what it might amount to, and how the Telephone Company and its wire-line network should relate to it. My own advocacy of participation by the Telephone Company by actually broadcasting and thereby ascertaining the future by experimentation was taking effect. We were to prepare estimates of what a Telephone Company broadcasting system might look like. |
1921, December 2, is the date of a memorandum prepared by myself and Dr. A.W. Nichols, of the Western Electric Co., on radio telephone broadcasting, constituting an estimate of a network broadcast system, with map, comprehending a national network of 38 stations tied together by wire lines, to be operated by the Telephone Company as a toll public-service broadcast system. Details of the layout were drawn up by an assistant, D.K. Martin. |
Ernst Alexanderson<br> The 1920s: radio as a vehicle for a facsimile system
[Owen D.] Young [of General Electric] had a great imagination. I remember once in New York he made a speech at some luncheon and said, "I'm getting tired of dots and dashes. Why don't you make a system so that you can put in a written letter and 'zip'--it will come out just as it is written at the other end." Some of the engineers chuckled, because he didn't know all the difficulties of doing that. But we proceeded to do the best that we could. We had to develop transmitters of 1,000 times higher frequency than those used in transatlantic telegraphy. We used 1,000 times higher radio frequency and a modulation frequency much higher, and so we could develop a facsimile system. |
We set up a transmitting antenna of that sort in San Francisco, receiving in Schenectady. Vice versa, we built a receiving station a few miles from the laboratory with antennas directed at San Francisco. The reception was very good, and we could talk with each other just as easily as we can talk across a table here. Then they put into the machine at San Francisco various kinds of pictures--we have some of the records of the pictures we sent. We transmitted facsimiles of whole newspapers and pictures and drawings and sketches, anything you wanted. That proved the possibility of something that is now commonplace. You are getting in the newspapers nowadays all the time pictures, printed, that are transmitted by that method. |
Young made his first suggestion in 1923, and it was about 1926 that we had successful transmission. You see, there was a lot of development work to be done--new tubes, new frequencies, the directive antennas and all that. In the problem of transmitting facsimile pictures, we had several separate problems. One was how to reproduce the picture itself, and the other was how to transmit the electrical information by radio. It was quite clear to us at the time when Young made his first suggestion that the radio waves, which we used at that time, were inadequate for transmitting information as rapidly as would be necessary for facsimile pictures or television. So therefore we went to the shorter wavelengths and had to develop transmitters for 1,000 times higher frequency. That led us to the frequencies that are now used in international communication. In facsimile we tried out a number of methods, which were all successful. We had photographic methods of recording, methods of recording by ink and by electrolytic process, and by carbon paper--like a typewriter. As a matter of fact, the most successful machine we had was developed by Charlie Young, son of Owen D. Young, who worked then in Schenectady and produced a very successful carbon machine for facsimile recording. |
I worked in the drafting department until the summer of 1903, and then I went into the testing department. In the spring of 1904 I started engineering. The first invention, which I had patented, was made when I was in the switchboard department. I was then a draftsman. It was a method of controlling the switch belonging to the line where the fault occurred, and other switches in parallel lines would not open at the same time. This is done by an inverse time relay. Those relays have been used extensively. That was my first patent. |
The Alexanderson alternator
The alternator is one of the inventions that I had to make in order to hold my job. The request came in from Reginald Aubrey Fessenden for a high-frequency alternator. That was passed along to the regular designers. They thought it was a rather fantastic thing, and I was crazy enough to undertake it. So that's the way it started. I first started to work out something that looked promising, and that was reported back to Fessenden through the regular channels. Then Fessenden wanted to see me. So I went to Boston and met him there and discussed further details with him. I went to see him several times during the progress of this work. Fessenden was a great personality and very impressive both in his physical stature and his mental makeup. He was so domineering that the people who worked with him said every week or so he fired them all when they didn't do what he expected them to do, and then he rehired them the next day. I got along with him very well, but a good many have a recollection of Fessenden's being so domineering that you couldn't get along with him. This is not my recollection. |
 | |
| |
I worked out something and delivered it to him--a high-frequency alternator--and he used it in his first test of radiotelephony in 1906. He had a high antenna tower at Brant Rock, and he used the alternator to generate the desired radio frequency. For telephone modulation, he used a water-cooled carbon microphone. This has gone into history--there was some music and some talk picked up on the ocean. Fessenden wanted an alternator for 100,000 cycles, and that was considered impossible. The highest frequency so far had been 10,000 cycles, and that wouldn't do at all--he wanted 100,000 cycles. I proceeded to design one for 100,000 cycles, but the one first designed couldn't be operated at more than 50,000 cycles because of certain difficulties that came in with the wooden armature. But it was operated at 50,000 cycles for those tests. When I came to see him, I showed him what I proposed, but he said he didn't think iron would work. He suggested it be worked out in another way, but in the end we came back to my first idea of using iron. It was the growth of an idea. He was a man with great imagination, and discussing it with him naturally led me on gradually. He has expressed himself at various times very appreciatively of what I did, but how much of it was his idea and how much of it was my idea is very difficult to disentangle. It was a productive partnership. He asked me to do something--I delivered it. The patent on the specific way of doing this is in my name because that was my idea, but of course in the general idea--setting the aim of where we wanted to go--Fessenden was naturally the leader. |
Marconi and Alexanderson's experimentation
We were testing then the magnetic amplifier with the idea of using it for telephony across the ocean. [Marconi] came down in the factory where we had the whole setup. It was a mess of instruments and wires and coils and everything, and he made the remark, "I can see you are doing good experimental work." He could see that we were experimenting. He was convinced by what he saw, and he decided that he would like to have our equipment installed in his station in New Brunswick. He would take out his own equipment and put in ours. Marconi wanted our equipment for telegraphy because that was the business at the time. Telephony of course was nonexistent. We were preparing to telegraph with it and then eventually to telephone with it. |
Later on, after the war, the Marconi Company wanted more alternators. We first installed the 50-kilowatt alternator, and it was put in immediate service. Our antenna radiation proved so much better than the old system that we got 10 times as much radiated power per kilowatt input by our system of multiple tuning. There were great doubts among the scientists whether that would work. The navy was interested in that at the time. Comparative tests were made, and it was found against quite a little opposition that it was so, and that our signals were the best. Our signals reached Europe very reliably, and our system was used during the war period from early 1917. |
Shortwave radio
The alternator was the key to radio, but radio is a much broader subject than the alternator, so I immediately switched to other ideas. I saw immediately that the alternator would do only for the long waves that are used in telegraphy, but for the shorter waves we needed a complete tube transmitter. So I worked on that. We first had an experimental station right out on the island in the river in front of here. We used a little shack as a radio station, and we established the basic principles of directive radiation. Then the station was built in South Schenectady. The ideas of the directive reception seemed logical to apply to directive transmission. So we built directive transmitting antennas. They are in use now and are known as beam antennas. The shortwave broadcast from Schenectady is received all over the world. |
|
| |
