TABLE OF CONTENTS K. Blair Benson
L. H. Hoke, Jr., L. E. Donovan, J. D. Knox, D. E. Manners, W. G. Miller, R. J. Peffer, J. G. Zahnen
Television receivers provide black-and-white or color reproduction of pictures and the accompanying monaural or stereophonic sound from signals broadcast through the air or via cable distribution systems. The broadcast channels in the U.S. are 6 MHz wide for transmission of conventional 525-line NTSC signals and DTV signals.
The minimum signal level at which analog television receivers provide usable pictures and sound, called the sensitivity level, generally is on the order of 10 to 20 ?V. The maximum level encountered in locations near transmitters may be as high as several hundred millivolts. The FCC has set up two standard signal level classifications, Grades A and B, for the purpose of licensing television stations and allocating coverage areas. Grade A is to be used in urban areas relatively near the transmitting tower, and Grade B use ranges from suburban to rural and fringe areas a number of miles from the transmitting antenna. The FCC values are expressed in microvolts per meter ( ?V/m) [1].
The standard transmitter field-strength values for the outer edges of these services for Channels 2 through 69 are listed in Table 7.1.1. Included for reference in the table are the signal levels for what may be considered city grade in order to give an indication of the wide range in signal level that a...
