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Coaxial 1940 Western Electric - Bell Laboratories; American Telephone & Telegraph Long Distance Tech
🕑 Added 2019-07-16 19:26:34 +0000 UTCmore at http://quickfound.net/
'COAXIAL - Bell Telephone Laboratories, Inc. On the value and principles of the coaxial cable. Explains how the coaxial carries many conversations at once and how calls over long distances are amplified by repeater stations. Shows details in the manufacture of coaxial cable. The first commercial stretch of cable is laid between Stevens Point, Wisc., and Minneapolis, Minn.'
Originally a public domain film from the National Archives, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.
The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).
https://en.wikipedia.org/wiki/Coaxial_cable
Wikipedia license: http://creativecommons.org/licenses/by-sa/3.0/
Coaxial cable, or coax (pronounced /ˈkoʊ.æks/) is a type of electrical cable that has an inner conductor surrounded by a tubular insulating layer, surrounded by a tubular conducting shield. Many coaxial cables also have an insulating outer sheath or jacket. The term coaxial comes from the inner conductor and the outer shield sharing a geometric axis. Coaxial cable was invented by English physicist, engineer, and mathematician Oliver Heaviside, who patented the design in 1880.
Coaxial cable is a type of transmission line, used to carry high frequency electrical signals with low losses. It is used in such applications as telephone trunklines, broadband internet networking cables, high speed computer data busses, carrying cable television signals, and connecting radio transmitters and receivers to their antennas. It differs from other shielded cables because the dimensions of the cable and connectors are controlled to give a precise, constant conductor spacing, which is needed for it to function efficiently as a transmission line...
Short coaxial cables are commonly used to connect home video equipment, in ham radio setups, and in measurement electronics. While formerly common for implementing computer networks, in particular Ethernet ("thick" 10BASE5 and "thin" 10BASE2), twisted pair cables have replaced them in most applications except in the growing consumer cable modem market for broadband Internet access.
Long distance coaxial cable was used in the 20th century to connect radio networks, television networks, and Long Distance telephone networks though this has largely been superseded by later methods (fibre optics, T1/E1, satellite).
Shorter coaxials still carry cable television signals to the majority of television receivers, and this purpose consumes the majority of coaxial cable production. In 1980s and early 1990s coaxial cable was also used in computer networking, most prominently in Ethernet networks, where it was later in late 1990s to early 2000s replaced by UTP cables in North America and STP cables in Western Europe, both with 8P8C modular connectors.
Micro coaxial cables are used in a range of consumer devices, military equipment, and also in ultra-sound scanning equipment...
1880 — Coaxial cable patented in England by Oliver Heaviside, patent no. 1,407.
1884 — Siemens & Halske patent coaxial cable in Germany (Patent No. 28,978, 27 March 1884).
1894 — Nikola Tesla (U.S. Patent 514,167)
1929 — First modern coaxial cable patented by Lloyd Espenschied and Herman Affel of AT&T's Bell Telephone Laboratories.
1936 — First closed circuit transmission of TV pictures on coaxial cable, from the 1936 Summer Olympics in Berlin to Leipzig.
1936 — World's first underwater coaxial cable installed between Apollo Bay, near Melbourne, Australia, and Stanley, Tasmania. The 300 km cable can carry one 8.5-kHz broadcast channel and seven telephone channels.
1936 — AT&T installs experimental coaxial telephone and television cable between New York and Philadelphia, with automatic booster stations every ten miles. Completed in December, it can transmit 240 telephone calls simultaneously.
1936 — Coaxial cable laid by the General Post Office (now BT) between London and Birmingham, providing 40 telephone channels.
1941 — First commercial use in USA by AT&T, between Minneapolis, Minnesota and Stevens Point, Wisconsin. L1 system with capacity of one TV channel or 480 telephone circuits...
