Open-Wire Crosstalk*

The tendency of communication circuits to crosstalk from one to another was grea tly increased by the advent of telephone repeaters and carrier current methods. Telephone repeaters multiplied circuit lengths many times, increased the power applied to th e wires, and at the same time made the circuits much more efficient in transmitting crosstalk currents as well as the wanted currents. Carrier current methods added higher ranges of frequency with consequently increased crosstalk coupling. Program transmission service added to the difficulties since circuits for transmitting programs to broadcasting stations must accommodate frequency and volume ranges greater than those required for message telephone circuits.