Rca1948FrequencyModu.. - The New Jersey Antique Radio Club

454 FREQUENCY MODULATION, Volume Iment, and to produce the swing in frequency necessary to attain anappreciable amount of output, comparatively large plate area must beused. If, however, the plates are made small in comparison and theirmovement is large (in the order of 30 per cent) to secure a usableoutput, the second harmonic distortion produced is then quite large,and was measured to be about 17 per cent in one instance. This largeamount of second harmonic content is too great to be canceled by thecomplementary nonlinear discriminator curve, except very close to theresonance point, where the range is limited and adjustment iscritical,£.