42 THE BELL SYSTEM TECHNICAL JOURNAL, JANUARY 1951 



ONE DIGIT 



TWO DIGITS 



THREE DIGITS 



FOUR DIGITS 



FIVE DIGITS ORIGINAL 



Fig. 6 — Test signal, Density wedge: one to five-digit transmission. 



digits. The remaining figures show some results obtained by transmitting 

 a television signal through the PCM system described in the first part of 

 the paper. 



Mr. B. M. Oliver and others of the television group of The Bell Telephone 

 Laboratories have developed a special low-noise film scanner that provides 

 an excellent test signal. This cquii)ment includes a rooter which, in com- 



