Rca1948FrequencyModu.. - The New Jersey Antique Radio Club

6a—498 FREQUENCY MODULATION, Volume Iresonant with the oscillating electric field over that which would resultfor zero magnetic field.When k < 1, the electron current is inductive, i.e., lags behind theelectric field producing it, and gives rise to an increase in resonantfrequency of the system.When k > 1 the electron current is capacitive,i.e., leads the electric field, and produces a decrease in resonant frequency.It should be noted that the above behavior applies to cases wherethe beam is not limited by space-charge effects and the orbits of theelectrons are not large enough to strike the walls of the cavity. Anestimate of the effects of these factors can be made for any special case.Electron LoadingIn order to calculate the electronic loading, we note from (76)the imaginary part of K given by (88) is required. Thusthat«o 2 |/|\e\= Im K. (95)2Q U (.mVyyXYZThe value of the ImK isImK = vrt«V Z (' rrV V ZI COS 2 ( c ) I I COS 2 (o) + u> c )Z I 2v \ Z I 2v—j;~~~ +—:irt> Y \— («o — °>o)2r2;jy'^oVi I) — (">o +