This report tells about the behavior of charged particles in the crossed fields with parametric generation of high-frequency oscillations in the initial period of time. Authors consider the radial resonator system, with two coaxial cylinders and inhomogeneous magnetic induction, and determine electron trajectories in crossed fields. Trajectories were determined in case of ac magnetic and electric fields with different frequency relations. Electron trajectories in crossed fields were calculated numerically by Runge-Kutta IV order of accuracy. In final authors demonstrate output characteristics for that generation.