by Tim J. Sturgeon
Originally written as a Masters Thesis, this is the fifth of a sequence of pages adapted from the full thesis. For the bibliographic references in the text go here.
Sonora Radiola Model 242, c. 1920.
In 1910 the two Danes who had come to America to help Elwell commercialize the Poulsen arc, Jensen and Albertus, along with Federal Telegraph employee E.S. Pridham, who had received a degree in electrical engineering from Stanford, left Federal Telegraph to start a research and development firm in Napa. Peter Jensen had been responsible for developing speech capacity for the Poulsen system in Denmark. By 1913, they had patented the "moving coil" loudspeaker, which was a vast improvement over existing speakers. By 1917 they had perfected a design that most loudspeakers of today are still based on. At the request of Commander George Sweet, Pridham and Jensen took their loudspeaker to Frank Steers of the Sonora Phonograph Company in Oakland. Sweet was based at the nearby Mare Island Navy Yard where he was negotiating contracts with Federal Telegraph for the Navy. He became interested in Pridham and Jensen's loudspeaker when he heard very loud voices coming from their laboratory as he was driving by. Steers was very enthusiastic about the performance of the speakers which had a wider tonal range and were capable of much higher volumes than anything he had heard. The group decided to merge their concerns under the name Magnavox, Latin for "big voice" (Morgan, 1967). The best on the market at the time were conical speakers from Westinghouse. Magnavox speakers were such an improvement that they soon got name recognition for their product (Heintz, 1974).
Original Magnavox logo, c. 1920s.
During World War I Magnavox developed an anti-noise microphone for the Navy that was installed on all of their four-motored NC seaplanes. This device allowed the crew to communicate with one another over the loud drone of the engines. One of these seaplanes, equipped with the Magnavox microphones, made the first flight across the Atlantic in May, 1919. Magnavox also built public address systems for destroyers and battleships that allowed the captain to address all personnel on board. The company received a national medal for its work during the war. After the war Magnavox built public address systems for factories, hospitals, and sports stadiums nationwide. Magnavox built the first public address system used in a presidential speech; in September, 1919 a Magnavox system was used by President Woodrow Wilson to speak to 50,000 people in San Diego.
Because Magnavox produced complete systems, they required powerful amplifiers to drive their loudspeakers. Because RCA had its own line of loudspeakers, they refused to supply Magnavox with vacuum tubes for their amplifiers. The company was forced to produce tubes in house, and turned to Ralph Heintz for designs that would not infringe on RCA tube patents. Heintz was a highly inventive Bay Area mechanical designer and electronics engineer who was highly skilled at "bootlegging" vacuum tubes. The chief engineer for Magnavox was Don Lippincott, who went on to become an important San Francisco patent attorney who worked closely with Ralph Heintz (who had been in ROTC with Lippincott at U.C. Berkeley) and Philo Farnsworth (who invented Television in San Francisco) on their patent difficulties with RCA. Eventually, Jensen split off from Magnavox to form a very successful company that produced loudspeakers only (Heintz, 1974).
Lee de Forest and the Invention of the Telephone Repeater, 1912
In 1910 Lee de Forest, who had earned a Ph.D in electrical engineering from Yale in 1899, came to San Francisco to supervise the installation of wireless telegraph sets on two Army transport ships anchored there. He was then co-owner of the New York-based North American Wireless Corporation which was using a vacuum tube receiver that he had invented in 1906. This early vacuum tube, the "audion," was a much more sensitive detector of radio signals than the spark sets of the time that relied on crystals for signal detection. As the sets were being installed, de Forest continued his experiments with voice transmission in a makeshift laboratory in San Francisco. He was convinced that the vacuum tube technology he was developing could overcome reliance on morse code by transmitting voice messages over the air. The wireless sets he had installed for the Army were tested, and messages sent from Hawaii were received clearly in San Francisco (Morgan, 1967).
Lee de Forest and his audion.
Photo: Wikimedia Commons
While this was going on, de Forest's New York partners, who had floated $1,507,505 worth of stock while investing only $345,649 in the company, were arrested for mail and stock fraud, leaving de Forest destitute in San Francisco and without a company (Morgan, 1967; Lewis, 1991). During his time in the Bay Area, de Forest had met some of the participants of the local radio industry, including Elwell. When de Forest told Elwell of his plight, Elwell immediately went to Beach Thompson, and asked him to hire de Forest. In 1911, de Forest was hired and given a laboratory, two assistants, and free rein to develop his ideas. De Forest was taken aback at first by the lack of formal training of his assistants, Herbert Van Etten and Charles Logwood, but with time grew to respect their inventiveness and willingness to try out new ideas.(20) When federal agents came to Palo Alto in 1912 to arrest de Forest for stock fraud associated with North American Wireless Corporation, Thompson bailed him out of jail for $10,000, allowing de Forest to continue his work.
De Forest Wireless System Responder, c.1903.
At Federal Telegraph, Fuller was in charge of building the ever larger and more powerful arc transmitters that were continuing to break daytime distance records. Arc transmitters were installed on the fleet of the San Francisco-based Pacific Mail Steamship Company, which offered San Francisco to Los Angeles service and transpacific service to Australia. De Forest was charged with the problem of amplifying the strength of incoming telegraph signals to the level at which they could be better received by Federal's "rotary ticker", which sent audible signals to the operator's headset. This device, developed by Logwood from Poulsen's telegraphone, was much more sensitive than crystal detection and became the worldwide industry standard until it was replaced by heterodyne reception (Fuller, 1975).
De Forest went back to San Francisco to collect the vacuum tube equipment left at his abandoned laboratory. He then set to work on the development of a vacuum tube amplifier. Within a few months, de Forest and his assistants had invented a tube that greatly exceeded expectations in its ability to amplify radio signals. A few months after discovery of the amplifying properties of de Forest's three element vacuum tube, the de Forest team found that the tube could also function as an oscillator, a device to generate radio signals. So, by 1912, de Forest had applied vacuum tube technology to all three stages of wireless radio communication: signal generation, signal reception (the audion), and signal amplification. Because the amplifier could boost weak signals as much as a million-fold, high power transmission eventually became less crucial and the cost of long distance wireless communication was radically lowered. Beyond transforming the wireless industry by signaling the demise of both spark and arc transmitter, the amplifier also allowed the proliferation of electronics into an ever widening a range of applications.(21)
De Forest was aware that his tube amplifier was an important development, and he immediately went to AT&T's Bell laboratories to demonstrate it. The telephone system was rapidly expanding at the time, but the technology was plagued by signals that weakened over long distances. Due to attenuation, telephone transmission over land wires was limited to about 1,000 miles, and over submarine cables to 100 miles. De Forest's amplifier made it possible to amplify signals at various "repeater stations" along transmission wire routes, allowing telephone messages to be sent over indefinite distances. In the spring of 1910 AT&T had embarked on a crash program to develop an amplifier that would enable long distance telephone connection to San Francisco in time for the opening of the Panama-Pacific Exposition in 1915. Four researchers, including H.D. Arnold, were brought in from Robert Millikan's physics research laboratory at the University of Chicago, where Millikan had been supervising research on the behavior of electron streams for ten years (Millikan, 1931).
Two years into the AT&T development effort, de Forest walked into Bell laboratories from California and handed them their solution. The team must have been stunned. AT&T did not invite de Forest to join their effort, but instead asked to keep de Forest's apparatus while they arranged to buy the patent rights for $100,000. Since he felt his new invention was covered by his 1907 patent for the "audion" receiving tube, de Forest agreed. After a year of waiting back in Palo Alto, de Forest was approached by a lawyer representing an anonymous party, who offered him $50,000 for the rights to the audion. De Forest, characteristically impatient, agreed to the deal only to find out later that the purchasing party had been AT&T. With his $50,000, de Forest left Federal Telegraph in 1913 to begin yet another company that was to fail: the Radio Telegraph and Telephone Company, located in the High Bridge section of the Bronx (Lewis, 1991).
The atmosphere of open-ended experimentation, intense work, and comraderie at Federal Telegraph created a situation that was rare for de Forest. He spent long hours with Van Etten and Logwood, not only in the laboratory, but also hiking in the hills nearby. Instead of constant embroilment with unscrupulous partners, failing businesses, and failing marriages, de Forest was able to immerse himself thoroughly in hard work and hard play. The pattern that emerges again and again in the early electronics industry in the San Francisco Bay Area is one where talented researchers were turned loose to solve a diffuse set of problems with little interference, seeking technological advance largely for its own sake. This was the environment that de Forest craved, but rarely experienced. While at Yale de Forest wrote in his diary: "...it seems the sweetest joy of life to closet myself with hard work in science. May this be my lot in life, to live in a little artificial world, away from the crowd and its friction, surrounded by companions and tasks of my own choosing, thus to gain insight in the great world and the universe of science; to battle always, yes, but with inanimate forces" (quoted in Morgan, 1967). The de Forest team was very productive during its short tenure at Federal Telegraph. Besides discovering the amplifying and oscillating properties of the three electrode vacuum tube, they established an innovative wire telegraph link between San Francisco and Los Angeles that used a duplex system of telegraphy allowing two operators to transmit simultaneously over a single set of wires. Telephone repeaters were used to boost the strength of the signal along the way (Lewis, 1991).
The development of the amplifier at Federal Telegraph did little for the company in the short term, but it became significant during the 1920s, when vacuum tube technology was improved to the point that it became the basis for all radio reception and transmission. Because de Forest had made his most important discoveries while an employee at Federal Telegraph, the company retained "shop rights" to produce tubes for internal use even though RCA had a monopoly on tube production through a pooling of AT&T tube patents with those of GE and Westinghouse after World War I.(22)
Radio Manufacturing in the San Francisco Bay Area During the 1920s
When Federal Telegraph return to the business of operating its commercial radiotelegraph service after World War I, Leonard Fuller left the company to help found the Colin B. Kennedy Radio Company in San Francisco (Fuller, 1976). In 1920 the radio "craze" was on. RCA had not anticipated the market for home sets, and small producers sprang up in every large city in the country. Most did not have licenses from RCA, but the market increased so quickly that RCA could do nothing about it at first. Ralph Heintz (1982) remembers, "...the radio industry broke loose, because there were a few stations with programs of sorts on, mostly phonograph records, or some studio work [Heintz built most of the early stations in the area]. That was in 1920 that all this started. In 1922, the industry went crazy. In San Francisco alone there must have been 25 or 30 manufacturers. The same in Oakland, and all over the United States they appeared. They didn't care anything about patents, There were just too many of them. Then the industry collapsed." Most of these companies were short lived, but a few such as Remler and Kennedy survived because they were well run companies able sell enough sets to justify the cost of an RCA licence, which RCA set in 1927 at a minimum of $100,000 per year at a fixed rate of 7.5% of net selling price (MacLaurin, 1949). Due to Fuller's design expertise, Kennedy radios were of extremely high quality, making them valuable collector's items today (Heintz, 1982).
Harold Elliot and the Single-Dial Radio Tuner
Victor RCA radio set, 1920s.
In 1925, a Federal Telegraph research engineer named Harold Elliot began experimenting with designs for a single-dial radio tuner for broadcast receivers. Home receivers of the day required users to manipulate four or five different knobs. One knob, controlling the local oscillator, had to be moved at a constant difference to the others, creating a process that was too complicated for the average user (MacLaurin, 1949). Elliot had a prominent role at Federal Telegraph working on various features of the arc transmitters. By 1927, Elliot had worked out detailed engineering and manufacturing specifications for a single-dial tuner. After careful research on various radio manufacturers, he brought the device to the attention of the Victor Phonograph Company. Victor, a company well known for its phonographs, was on the brink of entering the market for home radio sets. The company bought the rights to Elliot's device, which they dubbed the "microsynchronous tuner." Just as the company completed the design for the new receiver and was ready to go into production, Victor was merged with RCA. The set went into production as the "Victor Microsynchronous Receiver". This was the first single-dial receiver on the market. In 1978 Frederick Terman said, "I believe probably more sets of that microsynchronous model were sold than any other single chassis built up to that point." Terman met with Elliot in 1938, shortly after the completion of the San Francisco-Oakland Bay Bridge and the Golden Gate Bridge. Elliot told Terman that, in terms of retail price, the dollar value of all the Victor Microsynchronous Receivers sold was more than enough to build both bridges (Terman, 1978).
Fisher Research Laboratories
Gerhard Fisher came to Federal Telegraph in 1926 from New Jersey, where he had worked for de Forest. At Federal Fisher worked as an assistant to Frederick Kloster. During World War I Kloster had developed an electronic direction finder for the Navy. After the war, he came to Federal Telegraph to develop this technology for commercial shipping applications (Howeth, 1963). In 1928 Fisher invented the first metal detector in his Palo Alto garage. He called the device the "Metaloscope" or "M-scope". The M-scope found wide acceptance, becoming standard equipment for water and gas companies across the country that used it to locate buried pipes. Miners and treasure hunters soon began using the device. In 1929, Fisher developed airborne navigation aids that improved on designs from Kloster's radio direction finder. In 1936, Fisher opened Fisher Research Laboratories in Palo Alto to manufacture a variety of electronics products, including radio telephones and marine radios (Morgan, 1967).
Litton Engineering Laboratories
When Federal Telegraph was moved to New Jersey in 1932, Charles Litton continued to develop vacuum tube manufacturing equipment at his own company, Litton Engineering Laboratories. Litton's glass blowing lathe was able to mass produce glass tube blanks at uniform quality (Morgan, 1967). These machines were unique and gained wide acceptance. They were used for mass production by virtually all major vacuum tube makers, including General Electric, Westinghouse, and RCA (Fuller, 1976). According to Fuller (1976), a reserved individual not given to exaggeration (Everson; 1949; Morgan, 1967), Litton was a unusual combination of well trained inventor, electrical engineer, mechanical designer, and business manager. "He was a gifted designer that could do the seemingly impossible with metal and glass. Charlie Litton is without a doubt one of the cleverest men in his field in the world" (quoted in Morgan, 1967).
In 1940 Litton began manufacturing large high-powered "magnatron" vacuum tubes for ground based radar systems. During World War II tube production expanded and, as Litton said, "I woke up one day, and out of the clear blue sky I suddenly found myself the sole owner of a million-and-a-half-dollar concern" (quoted in Morgan, 1967). In 1946, Litton separated the tube business from his research laboratory and machinery business, forming Litton Industries. In 1953 Litton sold the tube business to "Tex" Thornton and moved his Laboratory to Grass Valley, east of the Sierra Nevada Mountains. Thornton had been in charge of the "whiz kid" team that reorganized Ford Motor Company for the peacetime production. According to a company history Thornton saw "the opportunity for a new type of company: one that was technologically oriented and could develop and apply these high technologies, primarily electronics, to different types of products and industries" (O'Green, 1989). The new company, dubbed the Electro Dynamics Corporation, was to grow into a diversified giant through the acquisition of small innovative companies. Its first acquisition was Litton Industries. In its first year the company reached three million dollars in sales from Litton's state-of-the-art magnatron tubes. Frederick O'Green, CEO of Litton Industries in 1988, tells the following story: "Shortly after we acquired Litton's company, Charlie was invited back to Washington to visit with the United States Navy. Some of the management team went along with him and found that the name of Charlie Litton opened doors in the Navy Department solely on the basis of the quality of the products he delivered. They came home and made their first opportunistic decision—to change the name of the company to Litton Industries" (O'Green, 1989). In 1980 Litton Industries had $4.2 billions dollars in sales.
20. On his return to the east coast in 1913, de Forest was to bring Logwood with him as an assistant. (Rosa, 1960)
21. It would be difficult to overstate the importance of de Forest's amplifier to the development of the electronics industry. In 1931, Robert Millikan, then director of the Norman Bridge Laboratory of Physics and chairman of the executive council of the California Institute of Technology, gave a nationally broadcast speech, introduced by President Hoover, in which he noted the importance of the de Forest three electrode amplifier. "The essential device, not only for the whole broadcasting art, and not only for most of modern long distance wire telephony, but also for all forms of speech reproduction and amplification, and this includes the greater part of the whole modern motion picture industry—not to mention picture reproduction at a distance in all its forms [television]—the essential underlying device for all this is simply one new instrument, the electron tube, telephone repeater or amplifier. The multiplicity of the new and wholly unforeseen practical uses which one new device or principle introduced into physics seems invariably to find always astonishes even the physicist who alone realizes how small and often simple is the fundamental scientific advance that has been made. Knock out that single instrument, the telephone repeater, and much of the whole structure of modern long-distance telephony, and practically all of radio and talking pictures, comes crashing to the ground."
22. The two instances in the literature on Silicon Valley that mentions the invention of the amplifier at Federal Telegraph, tie it to the Frederick Terman story by stating that de Forest's work was partly funded by Stanford University faculty and officials. (Rodgers and Larson, 1984; Basset, 1984). While this is true in a sense, because of the early investments of Jorden and Marx in Poulsen Wireless, de Forest's work had nothing at all to do with technical developments on the Stanford campus. The research group headed by Fuller, on the other hand, was closely associated with the Ryan Electric Laboratory, as we have seen.