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BELL SYSTEM TECHNICAL JOURNAL 



Fig. 12 — Arrangement of carrier supply and channel modem equipment at New 



York, N. Y. 



provided at intervals of about 100 miles. They differ from the flat 

 gain regulating repeater office chiefly in that they include twist cor- 

 rection regulation ^ and its associated amplifiers. Provision was made 

 at each twist gain regulating office for the installation of amplifier and 

 cable deviation equalizers. The equalizers were actually connected to 

 the circuits, however, only at such points as were indicated by lineup 

 tests. To permit lineup without delay, spare equalizers were available 

 at points where computations had indicated they might be needed. 

 Amplifier deviation equalizers were required at South Bend, Toledo, 

 Philadelphia, Richmond, and Greensboro on completed projects. It 

 was not found necessary to install cable deviation equalizers at any 

 point. Equalizer, flat gain, and twist gain amplifiers were installed in 

 three-bay groups with the equalizer equipment occupying the center 

 bay, and controller equipment in the fourth bay, similar to the ar- 



