The variations of the individual-oscillator amplitudes, generalized phase differences of the generated harmonics, and self-oscillation frequency of a multifrequency autodyne oscillator under the influence of reflected radiation for each of the generated harmonics are studied theoretically. Basic relations are obtained for analysis of the autodyne response of a multifrequency oscillator in synchronous and asynchronous operation. General conclusions are drawn concerning the self-oscillation characteristics of such autodynes that make it possible to improve the performance and expand the functional possibilities of autodyne systems for short-range radar.