Twisted telephone cables spacing - is achieved by radial fibres implanted in cable insulation to reduce conductor cross-talk

摘要

Single wires are laid in a helix. They require to be spaced away from each other in order to minimise mutual parasitic effects, cross-talk etc. The spacing technique is particularly intended for use in telephone circuits where the wires may be in twisted pairs or fours. Each individual wire (19) is provided with an insulating sheath (2) which is approx 0-2mm thick. Stiff bristles are implanted in this layer to hold adjacent wires apart. Each bristle or fibre is approx 1.0mm long, dependent on the inter wire capacity required. The fibre density is approx 400 g/km and their individual diameters are approx 25 denier.