See his letters, ed. by L. L. Leffingwell (1928, repr. 1967); biography by L. D. Rubin (1969); study by P. C. Butcher (1959).
The coaxial cable, which is virtually immune to external interference, consists of two concentric conductors separated by an insulator; the current in the inner conductor draws the current in the outer conductor toward the center rather than letting it dissipate outwards. Because they can carry a large number of signals simultaneously, coaxial cables are also used in cable television systems. The newest form of cable is the fiber-optic cable, developed in the 1970s. Instead of a copper conductor, a silica glass fiber carries digitized signals as pulses of light.
The insulated wire that conducts electricity from generator to consumer is also called a cable; it often contains multiple conductors and must be of sufficient gauge to carry large currents. Its insulation must withstand high voltages.
System that distributes television signals by means of coaxial or fibre-optic cables. Cable television systems originated in the U.S. in the late 1940s to improve reception in remote and hilly areas, where broadcast signals were weak. In the 1960s they were introduced in large metropolitan areas where reception is sometimes degraded by reflection of signals from tall buildings. Since the mid-1970s there has been a proliferation of cable systems that offer special services and which generally charge a monthly fee. Besides providing high-quality signals, some systems can deliver hundreds of channels. Another feature increasingly offered by cable operators is two-way, interactive communication by which viewers can, for example, participate in public-opinion polls as well as connect to the Internet. Cable operators are also involved in the development of video compression, digital transmission, and high-definition television.
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A cable is one or more wires or optical fibers bound together, typically in a common protective jacket or sheath. The individual wires or fibers inside the jacket may be covered or insulated. Combination cables may contain both electrical wires and optical fibers. Electrical wire is usually copper because of its excellent conductivity, but aluminium is sometimes used because it is lighter or costs less.
Bundling the conductors and eliminating multi-layers ensures a uniform bend radius across each conductor. Pulling and compressing forces balance one another around the high-tensile center cord that provides the necessary inner stability. As a result the cable core remains stable even under maximum bending stress.
Cables can be securely fastened and organized, such as using cable trees with the aid of cable ties or cable lacing. Continuous-flex or flexible cables used in moving applications within cable carriers can be secured using strain relief devices or cable ties. Copper corrodes easily and so should be layered with Lacquer.