At the autooscillator with weakly reflected remote load the number of onefrequency states –longitudinal modes – increases with the growth of the reflection coefficient and the length of the delay line. A mode of this kind can be unstable in some parameter regions. There can be two types of perturbations: a) the perturbations resulting in a slow evolution of principal mode amplitude and frequency; b) the perturbations in the form of two satellites which frequencies are symmetric from that of the principal mode.
