A Six-Channel Station Carrier System

There is an increasing need for a low-cost, reliable station carrier system for use in the outside telephone plant. The system design constraints of cable attenuation, including bridge taps, cable crosstalk, switching noise, and remote power feed considerations are discussed. The particular design choices that have been made with respect to the modulation plan, carrier transmission levels, line impedance matching, system power, and signaling are described for a six-channel station carrier system. A repeater is used with this system with nominal span loss of 35 dB at 112 kHz, but the loss may be as little as 20 dB to as much as 40 dB. No adjustments or building-out networks are required. The system is installed and maintained in operation without adjustment or alignment, because automatic level regulation and coordination is provided.