Page:United States Statutes at Large Volume 63 Part 2.djvu/696

 i]3 STAT.] MI'LTILATERAL-TELECO(IMMUNICATIONS-OCT. 2, 1947 (App. S RR) APPENDIX 6 Band of Frequencies Required for Certain Types of Radiocommunication. The width of the frequency band which is necessary in the overall system, including both the transmitter and the receiver, for the proper reproduction at the receiver of the desired information, does not necessarily indicate the interfering characteristics of an emission. For the determination of this necessary bandwidth, the following table may be considered as a guide. In the formulation of the table, the following working terms have been employed: B = Telegraph speed in bauds. N = Maximum possible number of black plus white ele- T-- aiu ments to be transmitted per second, in facsimile and television. M =Maximum modulation frequency expressed in cycles per second. D = Half the difference between the maximum and minimum values of the instantaneous frequencies; D being greater than 2M, greater than Nor greater than B, as the case may be. Instantaneous fre- quency is the rate of change of phase. t = Pulse length expressed in seconds. K = An overall numerical factor which differs accord- ing to the emission and depends upon the allowable signal distortion and, in television, the time lost from the inclusion of a synchronizing signal. 1993

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