The TJ Radio Relay System

This article presents a brief historical background to the A‐series of terminal units, used extensively in long‐haul and short‐haul transmission facilities to provide the first step of modulation from voice to carrier and the final step of demodulation from carrier to voice. Most of the paper is devoted to a description of the latest unit of this series — the A5 channel bank, which through the use of transistors and other modern components achieves significant improvements in size, power requirements and operating characteristics.

The Transistorized A5 Channel Bank for Broadband Systems

Blecher¹,

Hallenbeck²

1962

The New L Multiplex - System Description and Design Objectives

Hallenbeck¹,

Mahoney²

1963

This paper discusses in broad terms the design of a radically new family of multiplex terminals, designated the L multiplex, designed to work with any of several broadband transmission facilities. The relevant historical background of multiplex terminals is covered and design objectives for the new equipment are outlined. The new multiplex takes advantage of advances in the state of the art to reduce the size of equipment and increase reliability, while it retains the proven advantages of older equipment. Other advantages of the new multiplex include in‐service maintenance, decentralized carrier supplies, and increased flexibility. The latter permits its use with as few as 60 or as many as 1860 voice channels and also adapts it for use with wideband data service. Compatibility with older multiplex equipment was maintained where possible, but in order to meet future demands for broadband service, it was decided to modify older equipment rather than compromise the design of the new to maintain compatibility.

Carrier Supplies for L-Type Multiplex

Walter¹,

Evans²,

Ginty³

et al. 1963

This article describes the carrier and pilot supply equipment of the Ltype multiplex. Also discussed is the modernized carrier supply for the A-type channel banks described in an earlier paper.A short review of previous carrier equipment and recent developments in carrier application is followed by a general discussion of the design approach. Finally, specific circuits and equipment units are described.