radio 'case study'
...edia Britannica – www.britanica.com) Radio is based on the studies of James Clerk Maxwell, a Scottish physicist, who developed the mathematical theory of electromagnetic waves and predicted the existence of radio waves, and Heinrich Hertz, a German physicist, who devised an apparatus for generating and detecting them. Hertz demonstrated that rapid variations of electric current could be projected into space in the form of radio waves. (www.howstuffworks.com) Guglielmo Marconi, an Italian inventor, proved the feasibility of radio communication. He sent and received his first radio signal in Italy in 1895. The effective operating distance of this system increased as the equipment was improved, and in 1901, Marconi succeeded in sending the letter S across the Atlantic Ocean using Morse code. Marconi was early to exploit the commercial possibilities of wireless. In 1902 for most, wireless was still a science experiment, but once the details of Marconi’s advances became widely known, a large number of competitors sprang up on both sides of the Atlantic, many of who developed important refinements of their own. These refinements led to the diffusion of the radio (Donald McNicol, 2000). The U.S. Navy was quick to recognized radio's potential. Following successful tests by Italy and Great Britain, the Navy evaluated the radio in order to determine its usefulness under service conditions, and was quickly convinced of the value of radio. The U.S. Navy began to equip its entire fleet with transmitters, and also set up an extensive chain of coastal stations. Radio was also employed as an aid to civilian and military navigation (Donald McNicol, 2000). The Navy's impact on U.S. radio communications would continue to expand. In 1913, numerous shore stations started to handle commercial traffic in areas where there were no private stations, meanwhile, naval leaders lobbied for a government monopoly of radio transmitters. Beginning in 1915, the first vacuum-tube radio transmitters began to appear, a key technical development, which would eventually 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, including news and entertainment broadcasts (Thomas White, 1999). In 1906 Lee DeForest announced the first three-element vacuum-tube detector, which he called the Audion. The original Audion was capable of slightly amplifying received signals, but at this stage could not be used for more advanced applications, such as radio transmitters. The inefficient design of the original Audion meant it was initially of little value to radio, and it was hardly ever used, especially in light of its high cost and short life. Eventually vacuum-tube design was improved enough to make them more than novelties. Beginning in 1912, various researchers discovered that, properly constructed according to scientific and engineering principles, vacuum tubes could be employed in electrical circuits that made radio receivers and amplifiers thousands of times more powerful, and could also be used to make compact and efficient radio transmitters, which for the first time made radio broadcasting practical (Thomas White, 1999). Applications of Radio Radio's most important initial use was at sea, where it revolutionized communication, even though for the first two decades most radio transmitters could only transmit the dots-and-dashes of Morse code. The addition of radio operators aboard ship quickly captured the public imagination. All the major passenger liners were equipped with radio transmitters, radio kept vessels on transatlantic voyages in nearly constant communication with shore stations and each other. Radio greatly reduced the terrible isolation of ships during emergencies, and was quickly responsible for saving thousands of lives. This is one of the major positive outcomes of this invention (Donald McNicol, 2000). During World War I, governments began using radio to be alert of events and to instruct the movement of troops and supplies. Radiotelegraph circuits to other countries enabled persons almost anywhere to communicate with practically any place on earth (Thomas White, 1999). Following the establishment (1920) of station KDKA at Pittsburgh, Pa., the first commercial broadcasting station in the United States, technical improvements in the industry increased, as did radio's popularity. The radio receiver became a standard household fixture. Subsequent research gave rise to countless technical improvements and to such applications as radio facsimile, radar, and television (Thomas White, 1999). By 1908 the Hydrographic Office and the Naval Observatory reported that warnings about sea obstructions, plus daily time signals, were being "sent broadcast" on regular schedules by the Navy's coastal stations (Thomas White, 1999). Since 1923, pictures have been transmitted by wire, when a photograph was sent from Washington to Baltimore in a test. The first transatlantic radiophoto relay came in 1924 when the Radio Corporation of America beamed a picture of Charles Evans Hughes from London to New York (Donald McNicol, 2000). Analysis Many technological developments are applied if they increase industrial productivity, meet market demands and increase profits. The radio met this criterion hence allowing it to be a successful invention. Hughes describes a pattern by which large technological systems develop. Hughes implies that most large technological systems start with radical inventions, which generate a new system, as opposed to conservative inventions, which improve or add to an existing system. Hughes defines radical inventions as being made by independent people who are not part of an existing system (Hughes, 1990). The development of the radio occurred in a similar way to Hughes’ suggestion. Unlike the telephone, which was quickly adopted for business and home use, it took many years before radio was put to use. Technological determinism states, “the type of technology that is developed is independent of the type of society in which it is developed” (Beder, 1998, pp86). However technological determinism does not explain why society did not adopt the radio immediately. One reason why radio was not adopted immediately was due to a reverse salient. The radio was based on the discovery of electromagnetic waves (radio waves) and the invention of the vacuum tube. The combination of these two discoveries allowed the invention of the radio to occur. The numerous constraints in the development of the radio including economic, social and technical factors delayed wide spread broad casting until 1915. The development of the transistor was one of the technical constraints in the development of the radio. Engineers needed to develop a transmitter and a receiver for the radio to be of any use. The vacuum tube set up a reverse salient in the development of the radio (Hughes, 1990). The vacuum tube was seen as a possible solution to this problem. Research led to the development of the first three-element vacuum-tube detector in 1906. However this innovation did not seem to be a practical solution due to the vacuum tubes inefficiency, its short life and its large size. These flaws meant that the vacuum tube was initially of little value to radio. When engineers became aware of this reverse salient the concentrated on a solution for this problem. The effective use of engineering and scientific principals, in construction and design, enabled vacuum tubes to be employed in electrical circuits. The vacuum tubes made radio receivers and amplifiers much more powerful. Vacuum-tube radio transmitters began to appear in 1915. The use of vacuum tubes in radio shows how this technical constraint delayed the development of the radio. Social factors also played a leading role in the development of the radio. Social construction of this technology is clearly seen in the discovery of electromagnetic waves. Education, practical experience and interests enabled James Clerk Maxwell to predict the existence of radio waves, and Heinrich Hertz to devised an apparatus for generating and detecting electromagnetic waves. These scientists did not stop their research after they had made their findin...