. The Bell System technical journal . the same mid-rangeslope, showing that the general character of the distribution was thesame over the wide range of transmission conditions experiencedwithin this interval. To those familiar with transatlantic short-wavetransmission during 1930, the year 1934 would rate as comparativelyundisturbed, and yet these curves indicate that for an equal percentageof measurements or, as will be apparent later, for equal lost circuittime during these two years the difference in required transmissioneffectiveness would be only 13 or 14 db. Fig. 3 (b) shows that there
. The Bell System technical journal . the same mid-rangeslope, showing that the general character of the distribution was thesame over the wide range of transmission conditions experiencedwithin this interval. To those familiar with transatlantic short-wavetransmission during 1930, the year 1934 would rate as comparativelyundisturbed, and yet these curves indicate that for an equal percentageof measurements or, as will be apparent later, for equal lost circuittime during these two years the difference in required transmissioneffectiveness would be only 13 or 14 db. Fig. 3 (b) shows that there was relatively small db separation be-tween the 6-A noise distributions for 1930, 1932 and 1934 on the lowlatitude South American circuits but that the position of the curvesis reversed, 1930 being better than 1934. An examination of fieldintensit> data for these years indicates that this is due to a change innoise rather than to a change in signal transmission. Fig. 4 (a) compares the distributions for the circuits Buenos Aires-.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
