Polythene-insulated video-pair cables

This type of cable has insulation formed from polyethylene string and tape. Two insulated conductors are twisted together with fillers to form a balanced pair. A longitudinal copper tape with an outer helically-applied tape forms the screen. This cable can be made using the normal paper cable machines, and its attenuation and cross talk are both lower than those of normal paper cables. Curves of the frequency variation of impedance, attenuation and crosstalk are given. A pulse-reflection oscillogram shows the measured impedance uniformity of a 500 m length.