Transmission Design for Long Loops

The engineering of modern day subscriber's loop plant is discussed with particular emphasis on the use of fine gauge cables (26 to 22 gauge). Improved signaling limits of 1700 ohms dc outside plant resistance are employed; in conjunction with 48volt booster power supply, reliable signaling is assured well up to 4000 ohms. The loops are transmission engineered for D-66 loading and the new fixed gain voice repeater. The transmission performance is thoroughly discussed. The design procedure affords economical gauge selection, excellent transmission and elimination of telephone transmitter current supply loss, capability for immediate conversion to touchtone telephone operation and data transmission. The design-by-loss method is used throughout, and no transmission computations are required.