. The Bell System technical journal . Fig. 28—Aerial photograph of Manhattan Island showing locations of transmittingstation and obstructing high building area STUDIES IN RADIO BROADCAST TRANSMISSION 183 Such barriers to wave travel, situaled within a short distance fromthe source, seem, as we might exi)ect, to have a more extensive andserious influence upon effective broadcast distribution than similarobstructions at greater distances. It will be noticed that the obstruction falls very nearly upon thedirect line from the transmitter to the Stamford testing will also be evident la
. The Bell System technical journal . Fig. 28—Aerial photograph of Manhattan Island showing locations of transmittingstation and obstructing high building area STUDIES IN RADIO BROADCAST TRANSMISSION 183 Such barriers to wave travel, situaled within a short distance fromthe source, seem, as we might exi)ect, to have a more extensive andserious influence upon effective broadcast distribution than similarobstructions at greater distances. It will be noticed that the obstruction falls very nearly upon thedirect line from the transmitter to the Stamford testing will also be evident later after an understanding of Fig. 29, 150140130 120 no 100b^90 2 70 ■== Si X 403020j10 0. Zi° 25 27° 29° (Angle E of N from Transmitter)31- 35° 35° 37° 39° 41° 43° 45° 47°Across Manhattan 7 Wavelengtits from Station Fig. 29—Cross-section of radio shadow caused by high building area wherein the position of the Band Near Sound represents also thebearing of the Stamford station. The Riverhead station is notdirectly in line with the major obstruction. In certain sectors of the field strength contour map for station 2XBthere appears to exist a kind of wavy displacement of the contourlines forming a partial pattern of peaks and depressions side by general, this pattern must be differentiated from an ordinaryshadow area. A remarkable example of this sort of field distribu-tion is shown in Fig. 1 which is one section of a field strength surveymade for station 2XB. These contours are based entirely upondaytime measurements, and represent a condition which is stablethroughout the daylight period. Considerable difference in signallevel is apparent within short di
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
