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2-inch quadruplex videotape (also called 2″ quad video tape or quadraplex) was the first practical and commercially successful
analog recording Analog recording is a technique used for the recording of analog signals which, among many possibilities, allows analog audio for later playback. Analog audio recording began with mechanical systems such as the phonautograph and phonograph. ...
video tape Videotape is magnetic tape used for storing video and usually sound in addition. Information stored can be in the form of either an analog or digital signal. Videotape is used in both video tape recorders (VTRs) and, more commonly, videocassett ...
format. It was developed and released for the
broadcast television Broadcast television systems (or terrestrial television systems outside the US and Canada) are the encoding or formatting systems for the transmission and reception of terrestrial television signals. Analog television systems were standardized by ...
industry in 1956 by
Ampex Ampex is an American electronics company founded in 1944 by Alexander M. Poniatoff as a spin-off of Dalmo-Victor. The name AMPEX is a portmanteau, created by its founder, which stands for Alexander M. Poniatoff Excellence.AbramsoThe Histor ...
, an American company based in
Redwood City, California Redwood City is a city on the San Francisco Peninsula in Northern California's Bay Area, approximately south of San Francisco, and northwest of San Jose. Redwood City's history spans its earliest inhabitation by the Ohlone people to being a po ...
. The first videotape recorder using this format was built in the same year. This format revolutionized broadcast television operations and
television production A television show – or simply TV show – is any content produced for viewing on a television set which can be broadcast via over-the-air, satellite, or cable, excluding breaking news, advertisements, or trailers that are typically placed be ...
, since the only recording medium available to the TV industry until then was
film A film also called a movie, motion picture, moving picture, picture, photoplay or (slang) flick is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, feelings, beauty, or atmosphere ...
used for
kinescope Kinescope , shortened to kine , also known as telerecording in Britain, is a recording of a television program on motion picture film, directly through a lens focused on the screen of a video monitor. The process was pioneered during the 1940 ...
s. Since most
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ...
West Coast network
broadcast delay In radio and television, broadcast delay is an intentional delay when broadcasting live material, technically referred to as a deferred live. Such a delay may be to prevent mistakes or unacceptable content from being broadcast. Longer delays la ...
s done by the
television network A television network or television broadcaster is a telecommunications network for distribution of television program content, where a central operation provides programming to many television stations or pay television providers. Until the mid-1 ...
s at the time were done with film kinescopes that needed time for developing, the networks wanted a more practical, cost-effective, and quicker way to time-shift
television program Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertising ...
ming for later airing on the West Coast than the expense and time consumption of the processing and editing of film caused. Faced with these challenges, broadcasters sought to adapt
magnetic tape Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magnet ...
recording technology (already in use for recording audio) for use with
television Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertising, ...
as well. By 1954 the television industry in the US was using more film stock than all Hollywood studios combined. The term "quadruplex" refers to the use of four magnetic record/reproduce heads mounted on a headwheel spinning transversely (width-wise) across the tape at a rate of 14,985 RPM (for 960 recorded stripes per second) for
NTSC The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
525 lines/30fps-standard quad decks and at 15,000 RPM (for 1,000 stripes per second) for those using the
PAL Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields ( ...
625 lines/25fps video standard. This method is called quadrature scanning, as opposed to the
helical scan Helical scan is a method of recording high-frequency signals on magnetic tape. It is used in open-reel video tape recorders, video cassette recorders, digital audio tape recorders, and some computer tape drives. History Earl E Masterson fr ...
transport used by later videotape formats. The tape ran at a speed of either per second; the audio, control, and cue tracks were recorded in a standard linear fashion near the edges of the tape. The cue track was used either as a second audio track, or for recording
cue tone Cue or CUE may refer to: Event markers *Sensory cue, in perception (experimental psychology) *Cue (theatrical), the trigger for an action to be carried out at a specific time, in theatre or film *Cue (show control), the electronic rendering of the ...
s or
time code A timecode (alternatively, time code) is a sequence of numeric codes generated at regular intervals by a timing synchronization system. Timecode is used in video production, show control and other applications which require temporal coordinatio ...
for
linear video editing Linear video editing is a video editing post-production process of selecting, arranging and modifying images and sound in a predetermined, ordered sequence. Regardless of whether it was captured by a video camera, tapeless camcorder, or recorded in ...
. The quadruplex format employs segmented recording; each transversely recorded video track on a 2-inch quad videotape holds one-sixteenth (NTSC) or one-twentieth (PAL) of a field of interlaced video. (For NTSC systems, the math suggests 15 transverse head passes, each consisting of 16 lines of video, are required to complete one field.) This meant that 2-inch quad did not support "trick-play" functions, such as still, shuttle, and reverse or variable-speed playback. (In fact, the quadruplex format could only reproduce recognizable pictures when the tape was playing at normal speed.)) However, it was capable of producing extremely high-quality images containing about 400 horizontal lines of video resolution, and remained the ''de facto'' industry standard for television broadcasting from its inception in 1956 to the mid-1980s, when newer, smaller, and lower-maintenance videotape formats such as
Type C videotape 1–inch Type C (designated Type C by SMPTE) is a professional reel-to-reel analog recording helical scan videotape format co-developed and introduced by Ampex and Sony in 1976. It became the replacement in the professional video and broadca ...
superseded it. There were three different variations of 2-inch 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
video tape recorder A video tape recorder (VTR) is a tape recorder designed to record and playback video and audio material from magnetic tape. The early VTRs were open-reel devices that record on individual reels of 2-inch-wide (5.08 cm) tape. They were ...
(VTR), and *Super high-band, which used a pilot tone for better timebase stability, and higher
coercivity Coercivity, also called the magnetic coercivity, coercive field or coercive force, is a measure of the ability of a ferromagnetic material to withstand an external magnetic field without becoming demagnetized. Coercivity is usually measured in ...
tape. Most quad machines made later in the 1960s and 1970s by Ampex can play back both low and high-band 2-inch quad tape.


History

Time-shifting of television programming for the West Coast of the United States by the networks in the 1950s (in order to broadcast their programming at the same local time on the East and West Coasts) using
kinescope Kinescope , shortened to kine , also known as telerecording in Britain, is a recording of a television program on motion picture film, directly through a lens focused on the screen of a video monitor. The process was pioneered during the 1940 ...
films was quite a rushed and perilous ordeal. This was because there were only three 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 by the phone company (
AT&T AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile ...
) at the time), and then to record such to kinescope films, and finally to develop the film to be aired three hours later on the West Coast. This usually meant the kinescope was aired almost immediately after it came straight out of the developing equipment, still warm from the film dryer. These were referred to by the networks as "hot kines". By 1954, the networks used more raw film stock for kinescopes than all of the Hollywood film studios combined, spending up to $4,000 per half hour. 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 -wide tape. Ampex decided that instead of having the tape move at high speed past a stationary head to record enough bandwidth for video, the head would be made to move rapidly across the relatively slow moving tape. This resulted in the Mark I using
arcuate ''Arcuate'' (Latin for "curved") can refer to: Anatomy * Arcuate fasciculus * Arcuate line (disambiguation) * Arcuate artery (disambiguation), several arteries * Arcuate nucleus * Arcuate nucleus (medulla) * Arcuate ligaments of the diaphragm ...
scanning, which consisted of a spinning disk with a face (where the heads were mounted) which contacted 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 , 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. Ampex continued through the mid-1950s with the Mark II and Mark III rototype recorders. The Mark IV was the machine first publicly demonstrated at the National Association of Radio and Television Broadcasters (now the NAB) convention (the NAB Show) in
Chicago (''City in a Garden''); I Will , image_map = , map_caption = Interactive Map of Chicago , coordinates = , coordinates_footnotes = , subdivision_type = Country , subdivision_name ...
on April 14, 1956. After William Lodge of CBS finished his speech, the Mark IV replayed his image and words almost immediately, causing "pandemonium" among the astonished attendees.Wolpin, Stewart.
The Race to Video
". ''Invention & Technology'', Fall 1994.
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 Ampex took $2 million in orders for the machine in four days. Ampex later released the first manufactured models of quad VTR based on 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. The advertised price for the Ampex Videotape Recorder in late 1956 was $45,000 (). In 1957, shortly after Ampex's introduction of the 2-inch quad format,
RCA The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Com ...
introduced a quad-compatible VTR, the TRT-1A. RCA referred to it as a "Television Tape Recorder", since the word "videotape" was a trademark of Ampex at the time. Ampex developed and released updated and improved models of their quad decks, beginning with the VR-1000B in mid-1959. At that time, Ampex advertised that some 360-plus VR-1000s had been sold worldwide, more than 250 in the U.S.—roughly 30 at each network, 100 by independent stations, and 20 by production companies. The second-generation VR-2000 appeared in 1964. followed by a scaled-down economy version, the VR-1200, in 1966 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, using conventional 120 volt (V)
single-phase In electrical engineering, single-phase electric power (abbreviated 1φ) is the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison. Single-phase distribution is used when loads ...
household-type AC power to operate, rather than the 208 or 220 V
three-phase Three-phase electric power (abbreviated 3φ) is a common type of alternating current used in electricity generation, transmission, and distribution. It is a type of polyphase system employing three wires (or four including an optional neutral ...
AC power required by larger quad machines. RCA released later models of quad VTRs as well, such as the TR-22, TR-70, and TR-600.
CBS CBS Broadcasting Inc., commonly shortened to CBS, the abbreviation of its former legal name Columbia Broadcasting System, is an American commercial broadcast television and radio network serving as the flagship property of the CBS Entertainme ...
was the first television network to use 2-inch quad videotape, using it for a West Coast delay of '' Douglas Edwards and the News'' on November 30, 1956.Charles P. Ginsburg
. ''Memorial Tributes: National Academy of Engineering'', Vol. 7. 1994: The National Academies Press, Washington DC.
The CBS show ''
Arthur Godfrey's Talent Scouts ''Arthur Godfrey's Talent Scouts'' (also known as ''Talent Scouts'') was an American radio and television variety show which ran on CBS from 1946 until 1958. Sponsored by Lipton Tea, it starred Arthur Godfrey, who was also hosting ''Arthur Godf ...
'' on December 24, 1956 became the first entertainment program to be broadcast live to the nation from New York and taped for a time-delayed rebroadcast in the
Pacific Time Zone The Pacific Time Zone (PT) is a time zone encompassing parts of western Canada, the western United States, and western Mexico. Places in this zone observe standard time by subtracting eight hours from Coordinated Universal Time ( UTC−08:00 ...
. On January 22, 1957, the NBC game show ''
Truth or Consequences ''Truth or Consequences'' is an American game show originally hosted on NBC radio by Ralph Edwards (1940–1957) and later on television by Edwards (1950–1954), Jack Bailey (1954–1956), Bob Barker (1956–1975), Steve Dunne (1957–1958), ...
'', produced in Hollywood, became the first program to be broadcast in all time zones from a prerecorded videotape. The engineers at Ampex who worked on the development of 2-inch quadruplex videotape from the Mark I to the VR-1000 were
Charles Ginsburg Charles Paulson Ginsburg (July 27, 1920 – April 9, 1992) was an American engineer and the leader of a research team at Ampex which developed one of the first practical videotape recorders. Biography Ginsburg was born on July 27, 1920 in San ...
, Alex Maxey, Fred Pfost, Shelby Henderson, Charlie Anderson, and
Ray Dolby Ray Milton Dolby (; January 18, 1933 – September 12, 2013) was an American engineer and inventor of the noise reduction system known as Dolby NR. He helped develop the video tape recorder while at Ampex and was the founder of Dolby Labo ...
(who later went on to found
Dolby Laboratories Dolby Laboratories, Inc. (often shortened to Dolby Labs and known simply as Dolby) is an American company specializing in audio noise reduction, audio encoding/compression, spatial audio, and HDR imaging. Dolby licenses its technologies t ...
). As two inch machines became more reliable, they began to see use in outside broadcast (OB) production. The massive machines required their own truck to house and were incredibly labour intensive requiring considerable on site maintenance. Despite this, these machines allowed for OB video engineers to provide instant replays and generate opening sequences over which captions could be added.


Product models


Ampex

*VR-1000 (1956) (VRX-1000) FM Low band, three racks of tubes,
monochrome A monochrome or monochromatic image, object or palette is composed of one color (or values of one color). Images using only shades of grey are called grayscale (typically digital) or black-and-white (typically analog). In physics, monochr ...
. No timebase correction. *VR-1000 "Allen" or "Allenized" update kits (made for Ampex by Steve Allen at Allen Electronics) to color solid state, FM high band updateable, solid state servo system. *VR-1001 VR-1000 with the transport vertical. *VR-2000 (1964) Solid state, first color-capable quad VTR with high band. Optional Editec, Dropout compensation. Mark 10
head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may not ...
. Analog TBC. *VR-1100E (1966) Solid-state VR-1000. *VR-1195 (1966) VR1100 with many Ampex updates. *VR-1200 (1966) Solid state, color high-band. Analog TBC. Optional Editec. Scaled-down economy version of the VR-2000. *VR-3000 (1967) Portable VTR with a Mark 11 ball-bearing head. All-format VTR (NTSC/PAL/SECAM, 15 IPS/7.5 IPS, high-band/low-band). Digital TBC was possible, but required extensive mechanical modifications to the basic unit. Battery- or line-powered. *VR-3000B Portable VTR Improved version of VR-3000. Digital TBC was available as a plug-in accessory, and required no modifications to the basic unit. Improved batteries. *AVR-1 (1973) Very fast VTR, vacuum columns, vacuum capstan, air transport.
NTSC The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
/
PAL Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields ( ...
switchable. Analog TBC. *ACR-25 (1974) Cart VTR, with two AVR-1 type decks. *ACR-25B (1975) Cart VTR, ACR-25 with AVR-2 digital TBC. *AVR-2 (1974) Digital TBC, compact Quad used in studios and remote trucks. Uses 110-volt
single-phase In electrical engineering, single-phase electric power (abbreviated 1φ) is the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison. Single-phase distribution is used when loads ...
AC (other quad models require 220-volt or
3-phase Three-phase electric power (abbreviated 3φ) is a common type of alternating current used in electricity generation, transmission, and distribution. It is a type of polyphase system employing three wires (or four including an optional neutra ...
AC service, although the AVR-2 can be wired for either 110- or 220-volt service). *AVR-3 (1975) Last Ampex Quad, digital TBC. Vacuum capstan. Super high band. The VR-2000 & VR-1200 (and the VR-1100E & VR-1195, as well as some updated VR-1000 VTRs) used modules to correct the playback time base errors of the videotape.


RCA

*TRT-1A (1957) Tube VTR, 4 racks of tubes. *TRT-1B (1959) Tube VTR, three racks. An available option for color expanded this machine to six racks, which included the color processing equipment and color monitor. *TRT-1AC Prototype *TR-2 (1960) Tube VTR with some solid state. Low band or
monochrome A monochrome or monochromatic image, object or palette is composed of one color (or values of one color). Images using only shades of grey are called grayscale (typically digital) or black-and-white (typically analog). In physics, monochr ...
. *TR-11 (1961) Tube VTR with solid state PS-
Power supply A power supply is an electrical device that supplies electric power to an electrical load. The main purpose of a power supply is to convert electric current from a source to the correct voltage, current, and frequency to power the load. As ...
. *TR-22 (1961) Monochrome low band, later color version. *TR-22C (1964) High-band color. *TR-2 (1964) Record-only solid state. *TR-3 (1964) Playback-only solid state. *TR-4 (1964) Both, solid state. *TR-5 (1964) Console portable solid state. *TR-22D (1966) *TR-70 (1966) Solid state, high/low band with dropout compensation. High-band & low band color or monochrome. RCA's multi-standard machine *TR-70C (1967) TR-70 with digital TBC. *TR-50 (1967) TR-4 high band. *TR-60 (1969) High-band & low band color or monochrome. TR-60 is an updated TR-50. RCA's multi-standard machine 405/525/625 lines. The TR-60 and TR-70 were used in a master/slave configuration with the TCR-100 cart machines timesharing the video processing circuitry of the TR-60 and TR-70 machines when a SPU was not installed with the TCR100. *TCR-100 (1970) Dual-deck video cartridge machine. SPU-100 was the signal processing unit. Had many air-operated mechanisms *TR-61 (1972) High-band color, digital
servo Servo may refer to: Mechanisms * Servomechanism, or servo, a device used to provide control of a desired operation through the use of feedback ** AI servo, an autofocus mode ** Electrohydraulic servo valve, an electrically operated valve that c ...
system,
NTSC The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
/
PAL Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields ( ...
switchable, TR-60 is an updated TR-50. *TPR-10 (1975) High-band color portable. Larger than a VR-3000, Had color playback, US air force use a few. *TR-600 (1972) Last RCA Quad. Digital TBC, compact quad used in studios and remote trucks.


Bosch Fernseh

*BM-20 B&W Quadruplex tube TVR (1963-1970). *BCM-40 (1970-1972) Solid state, analog TBC. *BCM-40C (1972-1976) Updated BCM-40


Комета ( Kometa),

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

*Кадр-1 (Kadr-1) - B&W unit, tubes (1964) ; *Кадр-1Ц (Kadr-1Ts) - color unit, tubes ; *Кадр-3 (Kadr-3) - solid state ; *Кадр-3П (Kadr-3P) - 2-racks version intended for production trucks ; *Кадр-3ПМ (Kadr-3PM) ; *Кадр-5 (Kadr-5) .


ЛОМО (

LOMO LOMO (russian: Ленинградское Oптико-Mеханическое Oбъединение, Leningradskoye Optiko-Mekhanicheskoye Obyedinenie, Leningrad Optical Mechanical Association) is a manufacturer of medical and motion-picture lens ...
),
Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

* Электрон-2PМ (Electron-2PM).


Others

*Sony made an experimental 2" VTR in 1958, after seeing an Ampex VTR at NHK, but never sold any 2" quadruplex VTRs. *The VA-50 and VA-100 sold by Visual Electronics, USA. (1965-1970) by Jim Tharpe. Use many parts from Steve Allen, these at first were Allenized VR-1000s, sold as RB 1000. Then Visual switch to Allenized Bosch BM-20, colorizing them as VA-50 and VA-100. *WZT (Warszawskie Zakłady Telewizyjne, Poland) made VTR MW-623 (prototype in 1963) then improved to MW-645 (1965, commonly used in Polish Television) and finally 100% solid state MW-700C (1971). The VTRs were never sold abroad.


2-inch quad today

2-inch quad is no longer used as a mainstream format in TV broadcasting and video production, having long ago been supplanted by easier-to-use, more practical and lower-maintenance analog tape formats like 1" Type C (1976),
U-matic U-matic is an analogue recording videocassette format first shown by Sony in prototype in October 1969, and introduced to the market in September 1971. It was among the first video formats to contain the videotape inside a cassette, as oppo ...
and
Betacam Betacam is a family of half-inch professional videocassette products developed by Sony in 1982. In colloquial use, "Betacam" singly is often used to refer to a Betacam camcorder, a Betacam tape, a Betacam video recorder or the format itself. A ...
. Television and video industry changes to digital video tape (
DVCAM DV refers to a family of codecs and videotape, tape formats used for storing digital video, launched in 1995 by a consortium of camcorder, video camera manufacturers led by Sony and Panasonic. In the late 1990s and early 2000s, DV was strongly ...
,
DVCPro DV refers to a family of codecs and videotape, tape formats used for storing digital video, launched in 1995 by a consortium of camcorder, video camera manufacturers led by Sony and Panasonic. In the late 1990s and early 2000s, DV was strongly ...
and
Digital Betacam Betacam is a family of half-inch professional videocassette products developed by Sony in 1982. In colloquial use, "Betacam" singly is often used to refer to a Betacam camcorder, a Betacam tape, a Betacam video recorder or the format itself. All ...
) and high-definition ( HDCAM) are making analog tape formats increasingly obsolete. Operation of VR-1000-era machines required the skills of a highly trained video engineer. When a tape was changed, the operator spent as much as half-an-hour, "lining-up" the VTR — that is, carrying out specialized technical adjustments to calibrate the machine to the tape before it was ready for playback. From VR-1200/2000 onward, improvements in head manufacturing/refurbishing tolerances, timebase correction, and greater thermal stability of solid-state electronics made tape changes possible in under a minute and needed servo calibrations only once per shift. From AVR-1 onward, servos were self-calibrating and tape changes as fast as the operator could articulate threading. The few quadruplex VTRs which remain in service are used for the transfer and/or restoration of archival 2-inch quad videotape material to newer data storage formats, although mainstream TV serials from the 1950s to late 1960s have mostly already been remastered onto more modern media some years ago, even digitized within the last decade.


Specifications

* 2 Inch open reel to reel analog video system * Vacuum guide to support videotape for record * Tape speed 15 ips. (381 mm/s) .5 ips in half speed mode) * Video record FM signal * One analog control track (240Hz) 20 mils [bottom of videotape* Two analog audio tracks: 2 audio tracks or one audio and one cue tone track or one audio track and one linear timecode track * Analog audio track 70 mils [top of videotape] * Analog audio cue track 20 mils * Video track angle 89.5 deg. * Video track height/length ~ 1.82 inches, ~ 46.2mm * Four video record/play heads at 90 deg. (rotary transformer - Ampex, rotary brush - RCA) * Drum dia. 2 inches - (5.08mm) * Video penetration ~ .002 inches - 50 micron * 525-lines video has 32 video tracks * 625-lines video has 40 video tracks * Video scanner rotation: 525 line 14,400 rpm (240 rps) (1,000 stripes per second), 625 15,000 rpm * Video head write speed: 525 line 1508 ips (38.3 m/s), 625 39.9 m/sec (1570.8 ips) * Video track width 10 mils - .25mm * Video track pitch 15.6 mils - .40mm * 16.4 horizontal lines per head in 525. (64 lines recorded per rotation of the head drum assembly) * Video track per second 960. * Studio reel ~60 minutes, 4,800 feet. * Video FM modes: Low band, High Band, B&W, Super High Band


See also

*
VTR A video tape recorder (VTR) is a tape recorder designed to record and playback video and audio material from magnetic tape. The early VTRs were open-reel devices that record on individual reels of 2-inch-wide (5.08 cm) tape. They were ...
*
Videotape Videotape is magnetic tape used for storing video and usually sound in addition. Information stored can be in the form of either an analog or digital signal. Videotape is used in both video tape recorders (VTRs) and, more commonly, videocas ...
* Ampex 2 inch helical VTR * Contrast with
helical scan Helical scan is a method of recording high-frequency signals on magnetic tape. It is used in open-reel video tape recorders, video cassette recorders, digital audio tape recorders, and some computer tape drives. History Earl E Masterson fr ...
recording * Erhard Kietz's work at Ampex *
Lunar Orbiter Image Recovery Project The Lunar Orbiter Image Recovery Project (LOIRP) is a project to digitize the original analog data tapes from the five Lunar Orbiter spacecraft that were sent to the Moon in 1966 and 1967; it is funded by NASA, SkyCorp, SpaceRef Interactive, a ...
, recovered still images from physically similar tapes


References


General references

* TV Broadcasting, by Harold E. Ennes, 1971, Chapter 8, Page 356 to 388
quadvideotapegroup.com, Quad VTR on Planes


Inline citations


External links


Former OB video engineer discussed the differences between 2 inch machines and 1 inch video machines
with expanded information on the history of 2-inch Quad.



was the first TV entertainment program originating from the West Coast to be delayed for the West Coast on videotape.

with a section with pictures on 2-inch quad and Ampex's development and introduction of it.


Promotional kinescope
extolling the benefits of producing commercials on videotape instead of film.



page about early Color VTR.
Bosch 2" VTR 1970





Quad Videotape Group
helping to preserve the content, machines and the knowledge to use them in conjunction with the Library of Congress. Has historical information and discussion list.


Patents

* "Magnetic Tape Recording and Reproducing System", Ampex patent filed May 1955, issued December 1958. {{Homevid Videotape Film and video technology Audiovisual introductions in 1956 American inventions Discontinued media formats 1980s disestablishments