THE BELL SYSTEM 



TECHNICAL JOURNAL 



VOLUME XXVII, 1948 



Table of Contents 



January, 1948 



An Experimental Multichannel Pulse Code Modulation System of Toll 



Quality — L. A. Meacham and E. Peterson 1 



Electron Beam Deflection Tube for Pulse Code Modulation — 



R. W. Sears 44 



Metallic Delay Lenses— Winston E. Kock 58 



A Non-reflecting Branching Filter for Microwaves — W. D. Lewis and 



L. C. Tillotson 83 



A Note on a Parallel-Tuned Transformer Design — V. C. Rideoiit 96 



Statistical Properties of a Sine Wave Plus Random Noise — S. 0. Rice . 109 

 Noise in Resistances and Electron Streams — /. R. Pierce 158 



APRIL, 1948 



Microwave Repeater Research — H. T. Friis 183 



The Measurement of Delay Distortion in Microwave Repeaters — 



D. B. Ring 247 



Frequency Shift Telegraphy — Radio and Wire Applications— 



J. R. Davey and A . L. Matte 265 



Reflections from Circular Bends in Rectangular Wave Guides — Matrix 



Theory— 5. 0. Rice 305 



The Approximate Solution of Linear Differential Equsitions— Marion 



C. Gray and S. A . Schelkunof 350 



Potential Coefl&cients for Ground Return Circuits — W. H award Wise. . 365 



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