Abstract: A plenum cable having a plurality of twisted pair conductors enclosed by a jacket. A plurality of the twisted pair conductors has one insulating material thereon and at least one twisted pair conductor has a different insulation material thereon. In the preferred structure at least one twisted-pair conductor has flame retardant polyethylene or flame retardant polypropylene insulation and at least one other twisted pair conductor being insulated with fluorinated ethylene propylene, tetrafluoroethylene, or ethylenechloro-trifluoroethylene. The preferred twisted pair conductors have a center-to-center distance along any point of a 1000 ft. twisted pair conductor that is .+-.0.3 of an average center-to-center distance and/or have an impedance of 90 to 110 ohms and a variation of .+-.0.

Abstract: This patent describes a cable which is exceptionally suitable for high frequency signal transmission which includes at least two adjoined insulated conductors which are twisted together to form a pair. The pair(s) of adjoined insulated conductors are preferably encased within a thermoplastic, fluorocopolymer, or rubber type material. The embodiment may employ a metallic shield under the encasement. The variation of center to center conductor spacing within a pair as described above should be less than a value equal to about 0.03 times the statistical average of the center to center conductor spacing. The preferred cable has an average impedance of 90 to 110 ohms with a tolerance of .+-.5% when measured at high frequencies along any 1000 ft. of cable. Additionally, the two adjoined insulated conductors should have an adhesion strength of no more than 5 lbs. force.

Abstract: A plenum cable having a plurality of insulated conductors enclosed by a jacket. Each of the insulated conductors or twisted-pair conductors has a dielectric constant that varies .+-.0.25 from any other insulated conductor or twisted-pair conductor. In the preferred structure at least one twisted-pair conductor has flame retardant polyethylene or flame retardant polypropylene insulation and at least one other twisted pair conductor being insulated with fluorinated ethylene propylene, tetrafluoroethylene, or ethylenechloro-trifluoroethylene.

Abstract: An electronic data transmission cable with twisted pairs (16) and (18) twisted into group (32). To reduce electro magnetic interference between adjacent insulated conductors (12) twisted pair such as (16) and (18) are combined into group (32). Other groups (34) and (36) may be pulled in parallel or may be twisted together prior to forming cable (30).