. The Bell System technical journal . unit is assembled in anumber of longitudinal sections mechanically coupled by helical springsand electrically interconnected by means of bus tapes. The assembly iscomposed of 17 sections. Figs. 9 and 10 show the repeater make-up andan assembled unit. The sections consist of the circuit component, or components, mountedin machined plastic forms and enclosed in a plastic container w^hich inturn is enclosed in a housing of the same material.* The sections containcircuit components grouped functionally such as input coupling net-work, interstage, electron tube
. The Bell System technical journal . unit is assembled in anumber of longitudinal sections mechanically coupled by helical springsand electrically interconnected by means of bus tapes. The assembly iscomposed of 17 sections. Figs. 9 and 10 show the repeater make-up andan assembled unit. The sections consist of the circuit component, or components, mountedin machined plastic forms and enclosed in a plastic container w^hich inturn is enclosed in a housing of the same material.* The sections containcircuit components grouped functionally such as input coupling net-work, interstage, electron tube, or high \oltage blocking capacitor. Inthe case of the feedback network it was necessary to mount the networkin two sections because of the large numbers of components typical network, container and housing are shown in Fig. 11. The bus tapes are placed in grooves milled in the outer surfaces of the * The material used is methyl methacrj-late which was chosen for its chemical stability and good f|i mippMlli)— Fig. 10 — Overall view of the repeater unit. 80 THE BELL SYSTEM TECHNICAL JOURNAL, JANUARY 1957 Fig. 11 — Network section. section containers. Wiring spaces are machined into the ends of the con-tainers for connecting network leads to the bus tapes. The housing isplaced over the container and the buses and is closed by a plastic couplerplate which also forms part of the intersection couplers. The couplerplates are fastened to the housing with plastic pins. Between sections the bus tapes are looped toward the longitudinalaxis of the repeater unit. The dimensions of the loop are rigidly con-trolled so that as the unit is flexed during bending of the repeater, theloops always return to their original location between sections and donot short to each other or the metal outer container. The bus tapeshave either an electrical connection or lock at one end of each sectionto eliminate any tendency of the tapes to creep as the r
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
