GB302373A - An improved method of balancing telephone cables - Google Patents

Abstract

302,373. Pirelli-General Cable Works, Ltd., and Werren, H. T. June 16, 1927. Induction. preventing and minimizing. - A method of balancing a section of telephone or telegraph cable consists in measuring. the capacity unbalances of each of the cable lengths which constitute the section, and determining the crossings between the conductors of each two-pair core or quad at each successive joint to produce the minimum residual unbalance, the connections being such that similar cores are joined together throughout the section, for example, the colour scheme of the cores is preserved or a core has the same neighbours in each length. Groups of lengths may be balanced by the method and appropriate crossings between the groups subsequently determined. The crossings at some joints may be determined to minimize only the withinquad unbalance and at others, only the betweenquad unbalances, or, at some joints to minimize both these unbalances and at others, either of them. Auxiliary balancing condensers may be used. Some of the layers of cores in a cable may be balanced by known methods, and used for twowire working, and others by the present method used for four-wire working. A particular method described consists in determining the crossings required in a quad, hereinafter referred to as No. 1, to minimize the residual within-quad unbalances. The crossings in the next quad No. 2 are then determined to minimize both its withinquad unbalances and also the unbalances between quads No. 1 and No. 2. Quad No. 3 is now dealt with by taking into consideration its within quadunbalances and the unbalance between it and adjacent quads, the remaining quads being similarly treated.