J]!J1�©1Ffilit�J1 �@�OO�IT�'Frit@� Technical Journal of the International Telephone Arul Telegraph Corporation and Associate Companies

J]!J1�©1ffilIT�J1 �@�OO�IT�'frIT@� Technical Journal of the International Telephone arul Telegraph Corporation and Associate Companies • IN MEMORIAM-SOSTHENES BEHN GENERAL CONSIDERATIONS ON ELECTRONIC SWITCHING FULLY ELECTRONIC 20-LINE. AUTOMATIC TELEPHONE. EXCHANGE ELECTRONIC CIRCUITS IN MECHANOELECTRONIC SWITCHING SYSTEM HELSINKl-TAt'1PERE COAXIAL. CABLE LUMINESC:ENCE DECREASE. OF PHOSPHORS BY ELECTRON BURN AUTOMATIC FREQUENCY CONTROL FOR PULSED KLYSTRON Volume 34 JUNE, 1957 Number 2 www.americanradiohistory.com ELECTRICAL COMMUNICATI N Technical Journal of the International Telephone and Telegraph Corporation and Associate Companies H. P. WESTMAN, Editor J. E. ScHLAIKJER, Assistant Editor EDITORIAL BOARD H. G.Busignies H. H.Buttner R. S. Caruthers G. Chevigny A. G. Clavier E. M. Deloraine G. Goudet J. A. Henderson B. C. Holding J. Kruithof W. P. Maginnis A. W. Montgomery E. D. Phinney G. Rabuteau P. C. Sandretto N. H. Saunders C. E. Scholz T. R. Scott C. E. Strong F. R. Thomas H.B. Wood Published Quarterly by the INTERNATIONAL TELEPHONE AND TELEGRAPH CORPORATION 67 BROAD STREET, NEW YORK 4, NEW YORK, U.S.A. Edmond H. Leavey, President C. Douglas Webb, Secretary Subscription, $:1.00per year; single copies, 50 cents Copyrighted© 1957 by International Telephone and Telegraph Corporation Volume 34 JUNE, 1957 Number 2 CONTENTS IN 1-fEMORIAM-SOSTHENES BEHN . • • . • • . • • • • • . • • • • • • • • • . • • • • • • • • • • • • . • • . • • • • • • • • • • 79 GENERAL CONSIDERATIONS ON ELECTRONIC SWITCHING . • . • • • • • . 80 By Georges Goudet FULLY ELECTRONIC 20-LINE AUTOMATIC TELEPHONE EXCHANGE . • • • • . • • 92 By Claude Dumousseau PRINCIPLES OF ELECTRONIC CIRCUITS IN THE MECHANOELECTRONIC TELEPHONE SWITCHING SYSTEM . • • • • . • • • . • . • 102 By Hans H. Adelaar HELSINKI-TAMPERE COAXIAL CABLE . • . 122 By Olli Lehto and Raimo Piiytiiniemi LUMINESCENCE DECREASE OF PHOSPHOR SCREENS BY ELECTRON BURN ..•...•...••.... 130 By K. H. J. Rottgardt AUTOMATIC FREQUENCY CONTROL FOR A PULSED KLYSTRON .................•.....•.. 136 By Paul D. Ulm UNITED STATES PATENTS ISSUED TO INTERNATIONAL TELEPHONE AND TELEGRAPH SYS- TEM; NOVEJ\1BER 1956-}ANUARY 1957............................................ 142 RECENT TELECOMMUNICATION DEVELOPMENTS- "LES SEMICONDUCTEURS-DIODES, TRANSISTORS ET AUTRES APPLICATIONS" .. .. .. .. 91 FEDERAL RETURNS TO PALO ALTO .....••...••...... .....................· • .••... 141 CONTRIBUTORS TO THIS ISSUE .•.••••••••••••••••••.••••••.•••••••.......•......•••• 146 www.americanradiohistory.com SOSTHENES BEHN www.americanradiohistory.com lfn .1llemnrinm OSTHENES BEHN, founder of the Inter the largest telecommunication research and manu national Telephone and Telegraph Cor facturing organizations in the world, having S poration, died of a heart ailment on June plants in Argentina, Australia, Belgium, China, 6, 1957, in New York City. He was 75 years old. England, France, Italy, Japan, Norway, and Born on January 30, 1882, in St. Thomas, Spain. The Spanish telephone system was rebuilt Virgin Islands, of a Danish father and a French and modernized within five years. mother, Colonel Behn later became a citizen of Colonel Behn had meanwhile been developing the United States. the corporation in other directions. All America He first came to the United States in 1898 to Cables, Mackay Radio and Telegraph Company, learn the banking business. Six years later, he Postal Telegraph Company, Commercial Cable and his brother, Bernand, formed the banking Company, an interest in the Commercial Pacific and brokerage firm of Behn Brothers in Puerto Cable Company, and Federal Telegraph Company Rico. The need for rapid communication aroused were all acquired in 1927 and 1928. Additional their interest and they purchased some small local manufacturing and communication operating or telephone companies that were consolidated into ganizations were acquired both in Europe and the the Porto Rico Telephone Company in 1914. The Americas until the depression of the 1930s, which Cuban Telephone Company was acquired in 1916, was weathered well under his astute leadership. Colonel Behn becoming its president as one of It was during this trying period that his brother, the conditions of the sale. Bernand, died in 1933. Growth after the second On the entry of the United States into the first world war was dominated by the expansion of world war, he was commissioned a captain in the manufacturing activities in the United States. Army Signal Corps. In several administrative Colonel Behn relinquished the duties of presi posts and also as commander of the 322nd Field dent in 1948 and retired as chairman of the Inter Signal Battalion, he saw action at Chateau national Telephone and Telegraph Corporation in Thierry, St. Mihiel, and the Argonne. He was 1956 with the title of honorary chairman. discharged in 1919 as a lieutenant colonel, having Among his decorations were : Grand Cross, received the Distinguished Service Medal and the Order of Isabel la Catolica, Spain ; Grand Officer French Legion of Honor. of the Order of St. Gregory the Great, bestowed In 1919, the Cuban American Telephone and by his Holiness, Pope Pius XI ; Commander of Telegraph Company was formed to lay and oper the Royal Order of Daneborg, Denmark; Com ate a submarine telephone and telegraph cable mander of the Order of Leopold, Belgium ; Com between Cuba and the United States. mander of the Order of Merit, Chile; Commander The International Telephone and Telegraph of the Order of Carlos Manuel de Cespedes, Cuba; Corporation was established in 1920. A contract Officer of the Order of Simon Bolivar, Venezuela; awarded by the Spanish government in 1924 for Heraldic Order of Cristobal Colon, Dominican the rehabilitation, expansion, and operation of the Republic; Grand Cross, Cruz Roja, Cuba; Order Spanish national telephone network required that Al Comendador Benemerito Industrial, Portugal; much of the equipment be manufactured in Spain. and the Medal for Merit, United States. This led to the purchase in 1925 of the Inter national Western Electric Company, which was His passing marks the end of an era for the renamed International Standard Electric Corpora corporation and for those who knew the inspira tion. This bold stroke provided the International tion of his leadership, the warmth of his personal Telephone and Telegraph Corporation with one of ity, and the greatness of the man. 79 June 1957 • ELECTRICAL COMMUNICATION www.americanradiohistory.com General Considerations on Electronic Switching* By GEORGES GOUDET Laboratoire Central de Telecommunications; Paris, France HE MODERN CONCEPT of telephone crossbar system of Bell Telephone Manufactur systems is that any subscriber in a ing Company, Antwerp. large network should be able by dialing But the evolution toward quasistatic systems to reach speedily any other subscriber. These goes further; it is leading quite naturally to the networksT are continually increasing in size and introduction of electronic elements. complexity. In particular, they often extend In this category are not only electronic beyond the geographic boundaries of a nation. vacuum and gas tubes and semiconductor crystal The principal requirements to be met by the diodes and transistors, but also magnetic and exchanges in these networks are : low first cost, ferroelectric elements ; and, more generally, all high degree of reliability, ease of maintenance, the devices that fulfill their functions through long life, high operating speed, high transmission the movement of electric or magnetic particles quality, small volume and weight, and flexibility without displacement of weighable amounts of of operation. matter. In new systems, endeavor is being made to Let us examine the extent to which these introduce improvements in all these aspects. elements have already been used and the role In particular, in large towns where space is that they seem destined to play in the future. scarce and costly, it is possible to turn to better account the buildings already available for ex 1. Functions of a Telephone Exchange changes by reducing the volume of the switching equipment. During the last 40 years or so, these In a modern automatic telephone exchange considerations have in varying degrees fostered and, in principle, in automatic teleprinter the development of electromechanical devices switching exchanges, there are three essential having simplified and more-restricted mechanical categories of circuits, differentiated to a greater motion. or lesser degree. In the older systems-Strowger, panel, rotary, Ericsson, and R6-are complex mechanisms A. The switching circuit proper, or speech circuit, using either ratchets or continuously rotating functioning to bring about the connection of any parts with clutches and brakes. The brushes calling subscriber to any called subscriber. It have large circular or linear movements, or even must not only transmit the speech but also a combination of both. contribute to the signaling. In more-recent equipments of the crossbar type, the basic element is the electromechanical B. The memory circuit, its main role being to relay and the only movement is that of the register the orders issuing from calling sub armature. This mechanical simplicity, combined scribers. with the absence of sliding contacts, makes the relays in crossbar systems exceptionally sturdy. C. The control circuit, which has the task of They can remain in service for 20 years, or even bringing about the execution by the speech longer, without adjustment. In this

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