The analysis of the oscillating system with the waveguide expansion in the H-plane is given and its parameters are determined for a six-diode generator with parallel inclusion of diodes in the general electrodynamic system. The spectrum of oscillations of the natural frequencies in the symmetric expansion of the open waveguide type resonator and the conditions for reaching the maximum output power with the addition of several pulsed LPD in the resonator are determined. Their energy and frequency characteristics are investigated. The symmetric expansion of a rectangular waveguide in the - plane is considered as an open resonator of the waveguide type. Rectangular waveguides with hopping in the H-plane are the simplest open resonators and can find practical applications as power adders of active elements in the centimeter and millimeter wavelengths. The scheme of parallel inclusion of semiconductor pulse diodes in such electrodynamic systems is proposed, which allows to increase significantly the packing density of diodes and to improve heat dissipation. The analysis of the spatial distribution of the electric field of the "working" oscillation allowed to obtain valuable information on the location of the field hollows in the locations of semiconductor sources, as well as on the phase portrait of the oscillation field, which determines the way of inclusion of these sources. On the basis of theoretical studies, equations were obtained to calculate the basic parameters of a waveguide power generator of a pulse generator.