Quadruplex

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Ampex VR2000, a quadruplex video recorder - weight approx. 600 kg

Quadruplex , also known as two-inch quadruplex or two-inch quad , was the world's first practical video recorder system , developed by Ampex in 1956 .

The new technology was first used as part of regular broadcast operations on November 30, 1956, when CBS recorded the evening news program "Douglas Edwards and the News" in the Hollywood studio with an Ampex VRX-1000 VTR . The program with a duration of fifteen minutes was later broadcast on the west coast with a time delay.

Quadruplex uses a magnetic tape with a width of two inches (5.08 cm) which, for today's standards , is written on with a very low recording density. An image was divided into tracks every 15 to 16 lines . The belt speed is 15 inches (38.1 cm) per second.

The video bandwidth of this format is so high that it could also be used for the later introduced color video recording with only minor changes.

Quadruplex (colloquially known as two-inch ) was taken out of broadcasting in the 1980s with modernly equipped stations such as ZDF . The main reason for this was the comparatively labor-intensive operation of the systems. In order to keep archives usable, however, individual machines ("special devices") were kept until after the turn of the millennium.

The format is still in use in some television studios today. When Afghan television resumed its broadcasts, some of these machines were broadcasting regularly.

In television production and broadcasting, it was replaced by the 1-inch B and 1-inch C technology working with 1 inch (2.54 cm) wide magnetic tape on open reels , but also by professional video cassette formats such as U -Matic , Betacam-SP or Digital Betacam . Most broadcasters now rely on file-based production operations and thus on IT tapes, such as B. LTO .

Individual evidence

  1. ^ Charles P. Ginsburg: Volume 7 . In: National Academy of Engineering (ed.): Memorial Tributes . The National Academies Press, Washington DC 1994, ISBN 0-309-05146-0 , doi : 10.17226 / 4779 (English, nap.edu [accessed June 25, 2019]).

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