304,229. Siemens - Schuckertwerke Akt.-Ges Jan. 17, 1928, [Convention date]. Drawings to Specification. I duction, preventing.-In a long-distance cable balanced in the ordinary way to avoid cross-talk effects, residual coupling of the circuits is balanced out by additional electromagnetically coupled loops, preferably electrostatically screened from each other, inserted in the cable. The loops may consist of coils with electrically separated windings coupled inductively and disposed to act opposite to the inductive coupling between the circuits. Magnetic cores may be arranged in the coils. In another form, the loops consist of four cores twisted together and connected in pairs, which may be screened from each other electrostatically, by a layer of metal. In a further modification, the circuits may be surrounded at suitable points by loops of magnetic material. The loops may be applied in a coarse preliminary and finer stages.