L5 System: Repeatered Line

Abstract

The L5 repeatered line is presented from the viewpoint of a distributed equalization process. Reliable transmission of 10,800 circuits over 4000 miles of coaxial cable with minimum noise is the sole objective of this process. The strategy is to provide equalization in cause‐associated increments that place specific bounds on signal‐level excursions, thereby insuring an ultralinear, low‐noise predictable transmission medium. The individual causes of signal misalignment, both static and dynamic, are examined and the realization of the strategy, which forms a hierarchy of equalizers, is described.

L5 System: Overall Description and System Design

“…The particular method used to realize the deviation equalizer design is described in detail in Ref. 1. As described there, the L5 deviation equalizer, while in principle correcting the average design error, is realized in the final design stages using computer optimization routines that interact with the available adjustable equalizers.…”

L5 System: Physical Design

“…Elements of the basic repeater are the fundamental building blocks of the L5 system and appear in every repeater in the L5 equipment. 2 These basic elements, the preamplifier, the power amplifier, the low-frequency networks, and the line-build-out (LBO) network, are assembled to an inner chassis located inside a rugged die-cast aluminum outer housing. Figure 4 is a simplified repeater cross section showing the relative physical positioning of the apparatus on the inner chassis which is assembled to a flange protruding from the inner surface of the outer housing.…”