VOLUME XXV OCTOBER, 1946 no. 4 



THE BELL SYSTEM 



TECHNICAL JOURNAL 



DEVOTED TO THE SCIENTIFIC AND ENGINEERING ASPECTS 

 OF ELECTRICAL COMMUNICATION 



A Study of the Delays Encountered by Toll Operators in 

 Obtaining an Idle Trunk S. C. Rappleye 539 



Spark Gap Switches for Radar F. S. Gaucher, 



J. R. Haynes, W. A Depp and E. J. Ryder 563 



Coil Pulsers for Radar E. Peterson 603 



Linear Servo Theory Robert E. Graham 616 



Abstracts of Technical Articles by Bell System Authors. . 652 



Contributors to This Issue 655 



AMERICAN TELEPHONE AND TELEGRAPH COMPANY 



NEW YORK 



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