The numerical end experimental study of the energy and temporal characteristics of the output radiation of the CW medium-scale chemical HF/DF-laser with mechanical modulation of the optical resonator quality by the mirror rotation with frequency up to 1 kHz is carried out. In experiment, a peak power of the laser radiation pulses has exceeded the radiation power in CW mode of the HF-laser operation not less than in four times. The average power in repetitively pulsed mode is lower than one in CW mode, but it grows with increase of the modulation frequency. Time of the complete recovery of a small signal gain of the active medium, which is about 6 - 7 &mgr;s, is determined. Two numerical models are developed, which describe the dynamics of the laser oscillation in a mode of the resonator quality modulation for both HF- and DF-laser, some features of their operation are analyzed using these models.