Rca1948FrequencyModu.. - The New Jersey Antique Radio Club

68 FREQUENCY MODULATION, Volume Iin the band just inside the frequencies which correspond to the ends ofthe swings. When the deviation increases and the modulating frequencyremains constant, the total energy of the spectrum is spreadover a greater bandwidth, and the average amplitude of the side frequenciesmust decrease uniformly to maintain constant total energy inthe modulated carrier wave.The absolute maximum value of the Bessel function, for positivevalues of m, is shown by Figure 3. For a given modulation index, thismaximum occurs for a value of the order n slightly less than the modulationindex m. For example, for a modulation index of 1000 themaximum occurs at n = 991.91 and equals 0.06756. If the modulationindex is 10, the maximum occurs at n = 8.23 and equals 0.3210. TheF '"