2" Quadruplex (also called 2" Quad for short) was the first practical and commercially successful videotape format. It was developed and released for the broadcast television industry in 1956 by Ampex, an American company situated in Redwood City, California. This format revolutionized television broadcast operations and production, since the only medium available to the TV industry before then was motion picture film used for kinescopes, which was much more costly to utilize, had lower image quality than videotape, and took time to develop as well. 1956 was a leap year starting on Sunday of the Gregorian calendar. ... Ampex is based in Redwood City, California. ... Redwood City is the county seat of San Mateo County, California. ... Film refers to the celluloid media on which movies are printed Film is a term that encompasses motion pictures as individual projects, as well as the field in general. ... The term kinescope originally referred to a type of early television picture tube. ...

Since most West Coast network delays done by the TV networks at the time were done with film kinescopes that needed time for developing, the networks wanted a more practical, cost-effective, and much quicker way to time-shift programming for later airing in the West Coast (as well as a general production medium that wasn't as costly or time-consuming to edit & develop as film). These reasons were partly the motivation for a video recording technology using magnetic tape to be designed, in this case, 2" Quad.

The format gets its official name of Quadruplex from the fact that it uses 4 heads mounted on a headwheel spinning tranversely (width-wise) across the tape at a rate of 14,400 RPM for NTSC-standard Quad decks, and 15,000 RPM for those using the European PAL video standard. This method was called quadrature scanning (as opposed to the helical scan transport used by later videotape formats). The tape ran at a speed of either 7.5 or 15 inches per second, and the audio, control, and cue tracks were recorded in a standard linear fashion on the edges of the tape. The cue track was used either as a second audio track, or for recording cue tones or time code for editing. This article needs to be cleaned up to conform to a higher standard of quality. ... For other meanings of PAL see PAL (disambiguation). ... Helical Scan, or striping is a method of recording higher bandwidth signals onto magnetic tape than would otherwise be possible at the same tape speed with fixed heads. ... Timecode is also the title of a 2000 film directed by Mike Figgis which was shot in one continuous take. ...

A typical 4800 foot reel of 2" quad tape holds approximately 1 hour of recorded material at 15 inches per second.

A reel of 2" quad videotape compared with a modern-day miniDV videocassette

Each transversely-recorded track of video on a 2" Quad videotape holds one-sixteenth of a field of video, in other words, the format used segmented recording. This meant that 2" Quad was not capable of "trick-play" functions, such as still, shuttle, and reverse/variable-speed playback. But the format had quite sufficient image quality for broadcast (it produced about 400 lines of video resolution), and remained the de-facto format and industry standard for television broadcasting from its inception in 1956 to the mid-1980s, when newer, smaller, and less maintenance-prone videotape formats supplanted the role of 2" quad. Image File history File links Download high resolution version (1024x768, 585 KB)A reel of 2 Quadruplex (aka 2 Quad) videotape dating from the mid-1970s, compared with a modern-day miniDV digital videocassette for size comparison. ... Image File history File links Download high resolution version (1024x768, 585 KB)A reel of 2 Quadruplex (aka 2 Quad) videotape dating from the mid-1970s, compared with a modern-day miniDV digital videocassette for size comparison. ... A MiniDV tape Digital Video (DV) is a video format launched in 1996, which encodes video onto tape in digital format with intraframe compression, making it straightforward to transfer the video onto computer for editing. ...

There were 3 different variations of 2" Quad:

• Low-band, which was the first variety of Quad introduced by Ampex in 1956,
• High-band, which used a wider bandwidth for recording video to the tape, resulting in higher-resolution video from the VTR, and
• Super High-band, which used a pilot tone for better timebase stability, and higher coercivity tape.

Most later Quad machines made later in the 60s and 70s by Ampex could playback both low and high-band 2" Quad tape. In material science, the Coercivity of a ferromagnetic material is the intensity of the magnetic field required to reduce the magnetization of that material to zero after the magnetization of the sample has reached saturation. ...

The beginning of Quad

At the beginning of the 1950's, several companies along with Ampex, such as Bing Crosby Enterprises (BCE), and RCA were all competing to release a videotape format. RCA and BCE did release working prototypes of their recorders, but their downfall was that they all used a longitudinal (stationary-head) method of recording, much like audio tape recorders. This meant that the tape had to be recorded at a ludicrosly high speed (around 120 ips) in order to record a sufficient amount of bandwidth to reproduce a adequate video image (at least 2-3 MHz for a watchable image), in turn requiring large amounts of tape on large reels used by these early machines from RCA and BCE. In Britain at that time, the BBC developed a similar stationary-head VTR system that saw some on-air use, called VERA (Vision Electronic Recording Apparatus). RCA, formerly an initialism for the Radio Corporation of America, is now a trademark used by two companies for products descended from that common ancestor: Thomson SA, which manufactures consumer electronics like RCA-branded televisions, DVD players, video cassette recorders, direct broadcast satellite decoders, camcorders, audio equipment, telephones, and related... This article is an overview article about the Crown chartered British Broadcasting Corporation formed in 1927. ... Vera can refer to: Vera, Oklahoma Vera (Spain), a town in Almeria Vera, a novel by Elizabeth von Arnim Vera; or, the Nihilists, a play by Oscar Wilde [1] Bitstream Vera, a family of typefaces Vera (song) on Pink Floyds The Wall 245 Vera, an asteroid This is a...

Plus, time-shifting of television programming for the West Coast by the networks at the time (in order to broadcast their programming at the same local time in the East and West Coasts) using film kinescopes was quite a rushed and perilous ordeal. This was due to there being only 3 hours for the West Coast branches of the TV networks to receive video for the programming from the East Coast live via leased microwave relay or coaxial cable circuits provided from the phone company (AT&T) at the time, and then to record such to film kinescopes, and lastly to develop the film to be aired 3 hours later on the West Coast. This usually meant the kinescope film was aired almost immediately after it came straight out of the developing equipment, still warm from the film dryer used to dry the film prints coming out of the developing chemicals. These were referred to by the networks as "hot kines". According to the History of Tape Recording website, the networks used more raw film stock for kinescope delays for the West Coast than all of the Hollywood film studios combined. They were desperate to obtain a quicker, less expensive, and more practical solution. AT&T (formerly an abbreviation for American Telephone and Telegraph) Corporation (NYSE: T) is an American telecommunications company. ...

Ampex, seeing the impracticality of the prototype BCE and RCA VTRs, started to develop a more practical videotape format with tape economy in mind, as well as providing a solution to the networks' West Coast delay woes. Starting in 1952, Ampex built the Mark I prototype VTR, using 2"-wide tape. Ampex decided that instead of having the tape move fast across the head to record enough bandwidth for video, that the head move fast across the tape instead. This resulted in the Mark I using arcuate scanning, which consisted of a spinning disk, where its face (where the heads were mounted) was in contact with the tape (as opposed to the edge of the headwheel with transverse quadrature scanning). This resulted in an arc-shaped track being recorded across the width of the tape. Arcuate scanning resulted in a head-to-tape speed of about 2500 ips, but problems with timebase stability of the reproduced video signal from the tape led Ampex to abandon arcuate scanning in favor of the more reliable transverse scanning system. 1952 - Wikipedia, the free encyclopedia /**/ @import /skins-1. ...

Ampex soldiered on throughout the mid-50s with the Mark II and Mark III prototype recorders, which now used transverse scanning. The Mark II used FM modulation for recording video to tape, resulting in a much-improved, but still noisy video image (the Mark I used AM modulation), and the Mark III had improved signal-processing and servo electronics, resulting in perfect video being reproduced from the machine. The abbreviations FM, Fm, and fm may refer to: Electrical engineering Frequency modulation (FM) and its most common applications: FM radio, used primarily to broadcast music and speech at VHF frequencies FM synthesis, a sound-generation technique popularized by early digital synthesizers Science Femtometre (fm), an SI measure of length... Am is the present-tense, first-person, singular form of the verb to be, the copula of the English language. ... The term Servo can refer to, Servomechanism - usually just shortened to servo, is a device used to effect mechanical motion for a specified distance. ...

The Mark III worked perfectly, but its appearance was quite that of a prototype, and not a finished, saleable product. It was in a makeshift wooden case, with several parts of its chassis externally mounted in partially-filled racks. So, Ampex went on to integrate all of this into a sleek metal console and fully-populated rack-mount cases, and this became the Mark IV.

The Mark IV was the machine for the first public demonstration of the 2" Quad format, at the NARTB (now the NAB) convention in Chicago on April 14, 1956. The earlier Mark III was given some cosmetic improvements, and was also demonstrated at Ampex headquarters in Redwood City the same day. Both demonstrations were a success, and as a result, Ampex was swamped with orders for the new 2" Quad VTR. NAB may stand for: The United States National Association of Broadcasters National Australia Bank This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... Chicago, colloquially known as the Second City and the Windy City, is the third-largest city in population in the United States and the largest inland city in the country. ... April 14 is the 104th day of the year in the Gregorian calendar (105th in leap years). ... 1956 was a leap year starting on Sunday of the Gregorian calendar. ...

Ampex later released the first manufactured models of Quad VTR based off the Mark IV which were also prototypes, the VRX-1000, of which 16 were made. Machines made afterward were the final production models, and were designated as the VR-1000.

Shortly after Ampex's introduction of the 2" quad format, RCA in 1957 introduced a Quad-compatible VTR, the TRT-1A. RCA referred to it as a "Television Tape Recorder", since the word "Videotape" was copyrighted as a trademark by Ampex at the time. RCA, formerly an initialism for the Radio Corporation of America, is now a trademark used by two companies for products descended from that common ancestor: Thomson SA, which manufactures consumer electronics like RCA-branded televisions, DVD players, video cassette recorders, direct broadcast satellite decoders, camcorders, audio equipment, telephones, and related... 1957 was a common year starting on Tuesday of the Gregorian calendar. ...

Later on, Ampex would release later models of their Quad decks, such as the second-generation VR-2000 in 1967, and the AVR series of VTRs, AVR-1, AVR-2, and AVR-3 in the 1970s. The AVR-2 was the most compact of Quad VTRs, and could run off on regular 120 volt single-phase household-type AC power (Quad VTRs before then required 208 or 220-volt 3-phase AC power). 1967 was a common year starting on Sunday of the Gregorian calendar. ... The generation of AC electric power is commonly three phase, in which the waveforms of three supply conductors are offset from one another by 120°. These three conductors are commonly housed in a single conduit (e. ... 3-phase power, commonly used in industrial and theatrical installations, features three live legs of power and one neutral conductor. ...

RCA would also release later models of Quad VTRs as well, such as the TR-22 and TR-600.

CBS was the first television network to use 2" Quad videotape, using it for a West Coast delay of the program "Douglas Edwards and the News" on November 30, 1956. CBS would also delay for the west coast the first entertainment tv program on videotape, "The Edsel Show", on October 13, 1957. CBS (Columbia Broadcasting System) is a major radio and television network in the United States. ... November 30 is the 334th day (335th on leap years) of the year in the Gregorian calendar, with 31 days remaining, as the final day of November. ... 1956 was a leap year starting on Sunday of the Gregorian calendar. ... October 13 is the 286th day of the year (287th in leap years). ... 1957 was a common year starting on Tuesday of the Gregorian calendar. ...

The developing engineers at Ampex that worked on 2" Quadruplex videotape from the Mark I to the VR-1000 were Charles Ginsburg, Alex Maxey, Fred Pfost, Shelby Henderson, Charlie Anderson, and Ray Dolby (who later went on to found Dolby Laboratories). Categories: Stub | 1933 births ... The Dolby logo Dolby Laboratories, Incorporated (Dolby Labs) is a company specializing in audio compression and reproduction. ...

2" Quad today

Nowadays, 2" Quad is no longer used as a mainstream format in TV broadcasting and video production, having been supplanted by more modern, easier-to-use, more practical and less maintenance-prone formats like 1" Type C, U-matic, Betacam, DVCAM, DVCPro, and HDCAM. 1 Type C (designated Type C by SMPTE) is a professional open-reel videotape format co-developed and introduced by Ampex and Sony in 1976. ... U-matic is the name of a videocassette format developed by Sony in 1969. ... Betacam and VHS size comparison Betacam SP L (top), Betacam SP S (left), VHS (right) Betacam is a family of half-inch professional videotape formats developed by Sony from 1982 onwards. ... DVCAM is Sonys professional implementation of the DV standard, using 15 micrometre tracks instead of DVs 10 micrometre tracks. ... DVCPRO, DVCPRO 50, and DVCPRO HD refer to digital videotape formats using the DV codec, and devised by Panasonic. ... Betacam and VHS size comparison Betacam SP L, Betacam SP S, VHS Betacam is a family of half-inch professional videotape formats developed by Sony from 1982 onwards. ...

When it was in use, 2" Quad VTRs were a bear to maintain, usually requiring 3-phase power to operate (as mentioned earlier), as well as an air compressor to provide air pressure for the air bearing that the spinning transverse headwheel rode on due to its high rotational speed (some Quad VTRs used ball bearings instead, but these didn't last very long). They also required constant calibration of the discrete electronics used by the older Quad VTRs in order to maintain a high-quality picture suitable for broadcast. 3-phase power, commonly used in industrial and theatrical installations, features three live legs of power and one neutral conductor. ... Compressor has several meanings: A gas compressor is a mechanical device that takes in a gas and increases its pressure by squeezing a volume of it into a smaller volume. ... An air bearing is a bearing that literally consists of a layer of atmospheric air used as the working fluid for a fluid bearing. ...

2" Quad VTRs today are not used for broadcast or production service anymore. Instead, they are now used by video archives and transfer services, for the transfer and/or restoration of 2" quad videotape material to a newer format.

See also

• Videotape

Bottom view of VHS videotape cassette with magnetic tape exposed Videotape is a means of recording television pictures and accompanying sound onto magnetic tape as opposed to movie film. ...

External links

• A page on video systems theory, with expanded information on the history of 2" Quad
• Quadruplex Park, an online museum of 2" Quad VTRs
• A page on "The Edsel Show", the first tv entertainment program delayed for the West Coast on videotape
• The History of Recording Technology, with a section with pictures on 2" Quad and Ampex's development and introduction of such