Technological Innovations in Television

The first national live television broadcast in the U.S. took place on September 4, 1951 when President Harry Truman's speech at the Japanese Peace Treaty Conference in San Francisco, California was transmitted over AT&T's transcontinental cable and microwave radio relay system to broadcast stations in local markets.

The first live coast-to-coast commercial television broadcast in the U.S. took place on November 18, 1951 during the premiere of CBS's See It Now, which showed a split-screen view of the Brooklyn Bridge in New York City and the Golden Gate Bridge in San Francisco. In 1958, the CBC completed the longest television network in the world, from Sydney, Nova Scotia to Victoria, British Columbia. Reportedly, the first continuous live broadcast of a "breaking" news story in the world was conducted by the CBC during the Springhill Mining Disaster, which began on October 23 of that year.

The development of cable and satellite television in the 1970s allowed for more channels and encouraged businessmen to target programming toward specific audiences. It also enabled the rise of subscription television channels, such as Home Box Office (HBO) and Showtime in the U.S., and Sky Television in the U.K.

Television sets

In television's electromechanical era, commercially made television sets were sold from 1928 to 1934 in the United Kingdom, United States, and the Soviet Union. The earliest commercially made sets sold by Baird in the UK in 1928 were radios with the addition of a television device consisting of a neon tube behind a mechanically spinning disk (the Nipkow disk) with a spiral of apertures that produced a red postage-stamp size image, enlarged to twice that size by a magnifying glass. The Baird "Televisor" was also available without the radio. The Televisor sold in 1930–1933 is considered the first mass-produced set, selling about a thousand units.

Typical 1950s United States television set

The first commercially made electronic television sets with cathode ray tubes were manufactured by Telefunken in Germany in 1934, followed by other makers in France (1936),Britain (1936), and America (1938). The cheapest of the pre-World War II factory-made American sets, a 1938 image-only model with a 3-inch (8 cm) screen, cost US$125, the equivalent of US$1,863 in 2007. The most expensive model with a 12-inch (30 cm) screen was $445 ($6,633).

An estimated 19,000 electronic television sets were manufactured in Britain, and about 1,600 in Germany, before World War II. About 7,000–8,000 electronic sets were made in the U.S. before the War Production Board halted manufacture in April 1942, production resuming in August 1945.

Television usage in the United States skyrocketed after World War II with the lifting of the manufacturing freeze, war-related technological advances, the gradual expansion of the television networks westward, the drop in set prices caused by mass production, increased leisure time, and additional disposable income. In 1947, Motorola introduced the VT-71 television for $189.95, the first television set to be sold for under $200, finally making television affordable for millions of Americans. While only 0.5% of U.S. households had a television set in 1946, 55.7% had one in 1954, and 90% by 1962. In Britain, there were 15,000 television households in 1947, 1.4 million in 1952, and 15.1 million by 1968.

For many years different countries used different technical standards. France initially adopted the German 441-line standard but later upgraded to 819 lines, which gave the highest picture definition of any analogue TV system, approximately double the resolution of the British 405-line system. However this is not without a cost, in that the cameras need to produce four times the pixel rate (thus quadrupling the bandwidth), from pixels one-quarter the size, reducing the sensitivity by an equal amount. In practice the 819-line cameras never achieved anything like the resolution that could theoretically be transmitted by the 819 line system, and for color, France reverted to the 625-line CCIR system used by most European countries.

With advent of color television most Western European countries adopted PAL standard. France, Soviet Union and most Eastern European countries adopted SECAM. In North America the original NTSC 525-line standard was augmented to include color transmission with slight slowing down of frame rate.

Throughout the 1960s, television sets used exclusively vacuum tube electronics. This resulted in relatively heavy and unreliable TVs. In addition, vacuum tubes were poorly-suited to color television, as it required a large amount of tubes which caused further reliability problems. Because vacuum tubes only allowed for very simple NTSC/PAL filtering, the picture quality of early color sets was rather poor. The tint control that is still found on NTSC televisions originally was meant to correct the color burst phase's drifting when channels were changed. In addition, the large number of vacuum tubes required for color prevented the use of it in portable TVs.

By the early 1970s, solid-state electronics appeared and quickly displaced vacuum tubes in color TVs (black and white sets generally continued to be tube-based). This allowed for significantly more reliable TVs and better picture quality. 1971 was the first year that sales of color TVs in the US exceeded B&W ones. In other countries, color was slower to arrive and did not become common in Western Europe until the '80s.

By 1965, the FCC began requiring UHF tuners in all TVs sold in the United States. In 1971, there were 170 UHF stations in the country, mostly low-power ones that carried local programming. Previously, UHF support from TV manufacturers was sporadic. Most sets did not come factory-equipped with them, and often merely included an empty slot in the cabinet where an optional UHF tuner could be installed.

During the 1970s, electronic tuners began appearing in high-end TVs in place of traditional dials, and they would gradually become standard along with remote controls. Remotes had first appeared in the 1950s with Zenith's Space Command Control, but these were mechanical devices that emitted a high-pitched audio frequency that the TV detected. The first electronic remote controls did not appear until the 1980s.

1980s TV developments mainly centered around the above-mentioned features. Electronic television tuners also went hand-in-hand with the rise of cable television. Analog comb filters, first introduced in the '70s on high-end sets, gradually became more common. Black-and-white TVs virtually disappeared from the American market except for 5-inch, battery-powered models.

The first LCD TVs were introduced in 1988, small, handheld devices with a B&W screen that could not display the full NTSC resolution of 480 lines.

In the 1990s, three-line digital comb filters appeared on high-end TVs. In addition, composite video and S-video inputs began appearing to support devices like video games and VCRs.

Analog broadcast television in the United States ended on June 12, 2009 in favor of Digital terrestrial television (DTV) or digital-only broadcasting. [Top] [Back]

Source: Wikipedia