L-4 System: The 1–4 coaxial system

The l-4 coaxial system is a new solid state broadband facility designed to transmit 3,600 long-haul message channels on standard 3/8-inch coaxial cable. This paper describes system design characteristics and operating features of the new system, discusses system power, protection switching, and fault location aspects, reviews the performance results from field trial and initial commercial service tests, and compares these results with predictions. This paper also summarizes the environmental factors and design concepts affecting the system's physical design.