Low-frequency communication cables with porous polyethylene insulation, armoured TZPAUBpShp

1 Conducting cores - single-wire from copper soft round wire with diameter 0,9 mm or 1,2 mm.
2 Insulation of cores - film-porous-film, three-layer: layer of solid polyethylene, layer of porous polyethylene, layer of solid polyethylene. Nominal diameter of insulated cores is 1.9 mm and 2.4 mm.
3 Quadruple - cores with insulation of different colours are twisted in a star quadruple around a central cordel made of polyethylene composition. In a quadruplet, two conductors arranged diagonally form a working pair. The insulation of the cores of the first pair of fours has red and white colours, the second pair has blue and green colours. The twisted fours are wrapped in an open spiral with coloured cotton yarn of different colours.
4 Core:- is twisted from the fours in concentric twists.
5 Belt insulation - consists of polyethylene terephthalate tape and 5-7 tapes of cable paper.
6 The measuring tape is laid under the belt insulation.
7 Sheath - aluminium according to GOST 24641-81.
8 Protective cover according to GOST 7006-72 is put on ... .