File:The Bell System technical journal (1922) (14569349469).jpg

Identifier: bellsystemtechni18amerrich (find matches)
Title: The Bell System technical journal
Year: 1922 (1920s)
Authors: American Telephone and Telegraph Company
Subjects: Telecommunication Electric engineering Communication Electronics Science Technology
Publisher: (Short Hills, N.J., etc., American Telephone and Telegraph Co.)
Contributing Library: Prelinger Library
Digitizing Sponsor: Internet Archive

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construction was used because it was ex-pected to be slightly more economical and temporary voice usage ofthe conductors was not planned. One additional factor which, in special cases, influences the selectionof cables is that of carrier repeater spacing. This is brought about bythe fact that on multi-cable routes all of the cables may not followexactly the same route. For example, one cable may be aerial andthe other underground, and the two may be separated in some sec-tions; or underground cables, for conduit reasons, may follow differentroutes. It is desirable that the two cables used be near each other atrepeater points.^ One interesting feature in the construction of the Greensboro-Charlotte Cable is the method by which the cable was attached to themessenger. The cable was lashed to the messenger by means of agalvanized steel wire continuous between poles, as shown in Fig. 2.This method of installation is expected to reduce buckling, ring cuts, 550 BELL SYSTEM TECHNICAL JOURNAL
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Fig. 2—Method of lashing cable to messenger with galvanized steel wire shown in progress. and jumping, and avoids the necessity of splicing the cable undertension. Selection of Conductors for Carrier UseIn general, non-loaded cable pairs are not available in existing cablesand it is necessary to remove voice frequency loading from pairs APPLYING CARRIER TELEPHONE SYSTEMS 551 intended for carrier operation. As has been described previously in apaper in this Journal ^ the crosstalk mitigation plans in connectionwith type K carrier are designed on the assumption that cable pairswill be developed in units of 20 pairs for each direction of transmission.Further, the design of this carrier system contemplates the use of19-gauge pairs. Ten quads (20 pairs) were, therefore, selected in each cable in whichcarrier operation was planned. These quads were selected, for cross-talk reasons, from a large voice complement. Two-wire facilities maybe used for carrier where a sufficiently large complem

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