. The Bell System technical journal . Kig. 23—Relation of sunset shadow wall to noise at Belfast, Maine, U. S.—Oct. 30—Nov. 1, 1924 night-time belt as it proceeds from Europe to America and the corre-sponding rise in the static noise. The noise level curves are thesame as those shown in Fig. 14 for reception at Belfast, Maine. Therise commences about one hour before and continues for one houror so after sundown. This is for the fall season of the year. Asimilar chart for the sunrise conditions is given in Fig. 24. Although ASS SYSTEM hiyli iiiglit-tiniL- \aliies
. The Bell System technical journal . Kig. 23—Relation of sunset shadow wall to noise at Belfast, Maine, U. S.—Oct. 30—Nov. 1, 1924 night-time belt as it proceeds from Europe to America and the corre-sponding rise in the static noise. The noise level curves are thesame as those shown in Fig. 14 for reception at Belfast, Maine. Therise commences about one hour before and continues for one houror so after sundown. This is for the fall season of the year. Asimilar chart for the sunrise conditions is given in Fig. 24. Although ASS SYSTEM hiyli iiiglit-tiniL- \aliies started to lall <ilT soint- five hours before sun-down in Belfast, the more rapid drop was within some two hoursin advance. While these curves are f(^r hut a single clay, they arefairly representative of the average of a greater amount of change in the inclination of the sunset-sunrise curves with the. KiK. 24 -Krialioii of siinrisc- wall to noise at Belfast, Maim- I S —Oct .?0-Nov. 1, 1924 season of the year effects changes for .American rec» piioii soniewiiatsimilar to those shown for reception in ICngland, excei)t that for thesummer months (he coincidem-c is less delinite. It may he that thisis Ix-cause of the somewhat lower latitude of llic InitedStates terminaland (»f the reception of a greater propoiiimi of iho static from theXorlli . conlincnl. (//../.v//( ) :rii(K\ii •«,«) In K^-iuTal, lIuTifort, tlu- AiiUTtran ri-snlts arrortl with thosrcil)(l in l-jinland in indiratin^ (|uiti di-fuiitfly that a larjii pro-portion of ihf \f<l on ilir lon^i-r \va\r-. i-- of tropical origin. Si(iN.\i. TO NoisK R.\rii) It is. of roiirsi, the ratio of the signal to noisi- str(.n^;th which(ictirmines the commiiniration merit of a radio transmission channel. Variation with Frequency. A comparison for representative
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
