Rca1948FrequencyModu.. - The New Jersey Antique Radio Club

330 FREQUENCY MODULATION, Volume 1Fig. 12—Effect of low-pass filter.fore, of limited band width is to reduce the output at 2ir\d = ir and tocause the resulting wave to oscillate about the curve that would be obtainedwith unlimited band width. For the case when n = 5, the peakoutput is reduced from 9 .0 to 3 . 69 , or the output becomes 4 1 per cent of thatfor unlimited band width. The curves of Figure 13 show thaeffect of limitedband width. The variable on the axis of abscissas shows the number ofharmonics passed by the low-pass filter, and the other axis shows thepercent of peak amplitude compared to that for unlimited band width.Thus, if x = 0.9 and 10 harmonics are passed by the filter, the peak output1 _y-zhiO 6040