Broadcast Technology History: 1945-Present
An online exhibit by David L. Morton, Ph.D.
In 1999, the IEEE Broadcast Technology Society celebrated its 50th anniversary. The second oldest technical society (the group that became today's Signal Processing Society is slightly older) has a history that stretches to the formation of the Institute of Radio Engineers in 1912. This exhibit highlights just a few of the many accomplishments of broadcast engineers. Sponsored by the IEEE Broadcast Technology Society and the IEEE History Center.
- The Society: Radio Engineers and the IRE
The engineers who formed the core of the original Institute of Radio Engineers in the 1920s and 1930s were mostly from the broadcast industry. For about the first 30 years of its existence, "radio" was virtually synonymous with "broadcasting." But the years after World War II brought drastic changes to the field of electrical engineering. Electrical technology was moving rapidly; radar, computers, television, solid-state electronics, and space exploration were burgeoning fields.
Radio broadcasting emerged in the first decade of the 20th century and flowered in the United States and Europe during the 1920s. By the 1930s, virtually every country in the world had a network of radio stations and broadcasting engineers were in demand. The World War II years saw a considerable expansion in the use of broadcasting, as the U.S. and other nations established new networks to serve the entertainment and information needs of the military.
Regular television broadcasts began in 1936 in England and France and 1939 in the United States, but World War II delayed its widespread adoption.
- After World War II
The effect of the war could be seen in the membership of the IRE, which grew from 5,200 in 1940 to more than 18,000 by 1946. Membership continued to climb rapidly during the 1950s, finally surpassing the rival AIEE's membership in 1957, when total IRE membership, including students, reached 64,773. Students represented a fifth of that total, and the accelerating growth of the IRE's student membership was evidence of a society that was successfully riding the wave of a technological revolution.
- Postwar Broadcasting
By the time the BTS held its first meeting in 1949, radio broadcasting was undergoing important changes. Commercial AM network broadcasting reached a peak soon after the end of World War II. The broadcasting field in the late 1940s was clearly ripe for change. IRE (and later IEEE) engineers contributed to the reconstruction of broadcasting, designing new technologies that lowered costs and allowed local stations to produce their own programs. These innovations included station automation and studio equipment that allowed stations to run virtually unattended. Stations became less dependent on live programs, turning instead to recorded programs.
A major innovation of the postwar period was the magnetic tape recorder, which could be used to record and reproduce programs of almost any length, and could be set to run automatically. The Ampex and Magnecord Corporations developed a variety of recorders that became standard equipment in broadcast studios by the early 1950s. Broadcasting engineers also innovated an entirely new radio medium called Frequency Modulation. First proposed in its modern form by IRE member Edwin H. Armstrong, FM promised higher quality sound and virtually no interference. But despite initial enthusiasm for the new technology FM took hold slowly in the United States (it had somewhat more success in Europe). In fact, most FM broadcasters did not show a profit until the 1970s. FM broadcasting was the subject of considerable experimentation, as engineers looked for ways to enhance its appeal.
After a brief lag in 1946 and 1947 due to reconversion to civilian production, television receiver sales took off in 1948 and 35 million U.S. families had a TV by 1955.
- Cable TV
Zenith Corporation offered a simple type of subscription television service in 1951, but the development of coaxial cable distribution opened the door to the adoption of cable distribution in the 1960s and 1970s. Cable saw its greatest success in the U.S., where there were over 26 million subscribers by the early 1980s.
- In Living Color!
One major development affecting television cameras, video recorders, processing equipment, and receivers was the appearance of color. The FCC authorized color broadcasts in the U.S. in 1950, using the "color wheel" system of CBS. Later, the FCC reversed its decision and standardized the all-electronic color system developed by RCA, which was compatible with monochrome receivers. This backwards compatibility was a wise choice, as it turned out, because the number of color receivers in use was quite low until the late 1960s.
- Standards, Standards, Standards
Of the many pressing technical issues facing engineers was the establishment of broadcast standards. Engineers in different countries argued for different standards for such things as the number of lines on the screen. The United States and much of Europe went for a system sponsored by RCA (the European system was slightly modified for 50 Hz power), while France and Great Britain developed their own standards. A considerable amount of engineering effort went into problems related to interference between stations and the limited number of available channels. In 1953 the UHF band was opened for television broadcasting, but it became a "second class" band in part because of the way television receivers were designed. More successful in solving program distribution problems was cable distribution.
- The Merger
By the early 1960s, the IRE and the AIEE were discussing the possibility of merging, and on 1 January 1963 that union was accomplished when the IEEE was officially born. The new organization continued the IRE's structure of Professional Groups representing particular technical interests. This plan had been proposed in 1945 in response to the fear that audio engineers might form their own organization separate from the IRE (which they eventually did despite the formation of an IRE Audio Group in 1948).
- From Elevator Music to Quadraphonic Stereo
Single-sideband, for example, allowed beleaguered station owners to transmit fax messages, "background" music services, or other information on unused sidebands. Stereophonic broadcasting became widespread by the 1960s and eventually proved highly popular, but quadraphonic FM broadcasting won almost no fans. By continually striving for improvement, engineers found ways to make radio broadcasting a profitable medium in the face of competition from TV. Radio broadcasting has actually expanded since 1949; in that year there were about 2600 radio stations in the U.S., while there were almost 10,000 in operation fifty years later.
- From Professional Group to Society
The second of the new Professional Groups, authorized in 1948, was the Broadcast Engineers Group. From the first meeting of the group in 1949 to 1976, the Broadcast Engineers Group was not concerned with broadcast receivers, but in 1975 merged with the Consumer Electronics Group (formerly known as the Group on Broadcast and Television Receivers). There were other name changes before AIEE/IRE merger in 1963. The IEEE Professional Technical Group on Broadcasting, as it was called after 1963 absorbed the Committee on Video Techniques and the Television systems Committee in 1967 but was merged into the IEEE Broadcast, Cable, and Consumer Electronics Society following the re-organization of the Institute into Technical Societies. Then, in 1982, the Society assumed its current form when the Consumer Electronics society was made independent.
Only five countries had television service in 1950, but that number had risen to 138 in 1980, when there were an estimated 400 million sets in use. Broadcast engineers contributed fundamentally to the establishment and upgrading of TV service around the world.
- Satellites and HDTV
From the 1970s to the present, broadcast engineers contributed to the development of satellite distribution. Many different systems were proposed or built, including the early satellite-based, High Definition Television system in Japan, direct satellite broadcasting for remote areas such as Alaska or the African continent, and the more recent DBS consumer satellite broadcast system. High Definition Terrestrial Digital Television is being implemented throughout the world. Digital Television stations are going on the air in the United States and will run concurrent with NTSC stations until the build-out period has been completed.