Terrestrial television is a type of television broadcasting in which the television signal is transmitted by radio waves from the terrestrial transmitter of a television station to a TV receiver having an antenna. The term terrestrial is more common in Europe and Latin America, while in the United States it is called broadcast or over-the-air television; the term "terrestrial" is used to distinguish this type from the newer technologies of satellite television, in which the television signal is transmitted to the receiver from an overhead satellite, cable television, in which the signal is carried to the receiver through a cable, Internet Protocol television, in which the signal is received over an Internet stream or on a network utilizing the Internet Protocol. Terrestrial television stations broadcast on television channels with frequencies between about 52 and 600 MHz in the VHF and UHF bands. Since radio waves in these bands travel by line of sight, reception is limited by the visual horizon to distances of 40–60 miles.
Terrestrial television was the first technology used for television broadcasting. The BBC began broadcasting in 1929 and by 1930 many radio stations had a regular schedule of experimental television programmes. However, these early experimental systems had insufficient picture quality to attract the public, due to their mechanical scan technology, television did not become widespread until after World War II with the advent of electronic scan television technology; the television broadcasting business followed the model of radio networks, with local television stations in cities and towns affiliated with television networks, either commercial or government-controlled, which provided content. Television broadcasts were in black and white until the transition to color television in the 1950s and 60s. There was no other method of television delivery until the 1950s with the beginnings of cable television and community antenna television. CATV was only a re-broadcast of over-the-air signals. With the widespread adoption of cable across the United States in the 1970s and 1980s, viewing of terrestrial television broadcasts has been in decline.
A slight increase in use began after the 2009 final conversion to digital terrestrial television broadcasts, which offer HDTV image quality as an alternative to CATV for cord cutters. Following the ST61 conference, UHF frequencies were first used in the UK in 1964 with the introduction of BBC2. In UK, VHF channels were kept on the old 405-line system, while UHF was used for 625-line broadcasts. Television broadcasting in the 405-line system continued after the introduction of four analogue programmes in the UHF bands until the last 405-line transmitters were switched off on January 6, 1985. VHF Band III was used in other countries around Europe for PAL broadcasts until planned phase out and switchover to digital television; the success of analogue terrestrial television across Europe varied from country to country. Although each country had rights to a certain number of frequencies by virtue of the ST61 plan, not all of them were brought into service. In 1941, the first NTSC standard was introduced by the National Television System Committee.
This standard defined a transmission scheme for a black and white picture with 525 lines of vertical resolution at 60 fields per second. In the early 1950s, this standard was superseded by a backwards-compatible standard for color television; the NTSC standard was being used in the Americas as well as Japan until the introduction of digital terrestrial television. While Mexico have ended all its analogue television broadcasts and the US and Canada have shut down nearly all of their analogue TV stations, the NTSC standard continues to be used in the rest of Latin American countries while testing their DTT platform. In the late 1990s and early 2000s, the Advanced Television Systems Committee developed the ATSC standard for digital high definition terrestrial transmission; this standard was adopted by many American countries, including the United States, Dominican Republic, Mexico, El Salvador and Honduras. The Pan-American terrestrial television operates on analog channels 2 through 6, 7 through 13, 14 through 51.
Unlike with analog transmission, ATSC channel numbers do not correspond to radio frequencies. Instead, a virtual channel is defined as part of the ATSC stream metadata so that a station can transmit on any frequency but still show the same channel number. Additionally, free-to-air television repeaters and signal boosters can be used to rebroadcast a terrestrial television signal using an otherwise unused channel to cover areas with marginal reception. Analog television channels 2 through 6, 7 through 13, 14 through 51 are only used for LPTV translator stations in the U. S. Channels 52 through 69 are still used by some existing stations, but these channels must be vacated if telecommunications companies notify the stations to vacate that signal spectrum. By convention, broadcast television signals are transmitted with horizontal polarization. Terrestrial television broadcast in Asia started as early as 1939 in Japan through a series of experiments done by NHK Broadcasting Institute of Technology.
However, these experiments were interrupted by the beginning of the World War
Things Viral is the second album by American drone metal band Khanate, released in 2003 on the Southern Lord label. The CD was released in two versions: a European digipack version and a U. S. jewelcase version. There was a LP version on LOAD Records with 1000 gatefold plus 12" copies released. A video was made for the song "Dead". All Songs Arranged By Khanate. "Commuted" – 19:13 "Fields" – 19:50 "Dead" – 9:27 "Too Close Enough To Touch" – 11:11 "Commuted" "Fields" "Too Close Enough To Touch" "Commuted" Alan Dubin: Vocal Stephen O'Malley: Guitars James Plotkin: Bass, Synthesizers Tim Wyskida: Drums, Percussion Produced, Engineered & Mixed By James Plotkin "Things Viral" at discogs
The ELBE to HAYN series of early, steam locomotives were equipped with tenders and operated by the Leipzig–Dresden Railway Company. The five locomotives were delivered to the LDE in 1849 by Borsig of Berlin, they were given the names ELBE, BERLIN, MULDE, MEISSEN and HAYN. The engines were retired in 1868/69; the boiler was rivetted from several sections. The outer firebox was equipped with a semi-circular dome that extended forward over the boiler barrel and acted as a steam collection space. In addition there was a steam dome on the front section of the boiler; the two spring balance safety valves were located on the steam dome of the outer firebox. The steam cylinders were located externally, unlike those on English locomotives, which avoided the need for a cranked axle that would have been expensive and difficult to manufacture; the steam engine was equipped with inside Borsig double valve gear driven via two eccentric cams. The locomotives did not have their own braking equipment. Braking could only be achieved using the hand-operated screw brake on the tender.
The locomotives had Kirchweger condensers to pre-heat the feedwater. An external feature of, the second chimney on the tender. Exhaust steam was led from the steam chest to the tender through a low-down, 100 mm, connecting pipe. Royal Saxon State Railways List of Saxon locomotives and railbuses Leipzig–Dresden Railway Company Näbrich, Fritz. Lokomotivarchiv Sachsen 1. Berlin: transpress VEB Verlag für Verkehrswesen. Preuß, Erich. Sächsische Staatseisenbahnen. Berlin: transpress Verlagsgesellschaft mbH. ISBN 3-344-70700-0