  It is shown that the scattering of electromagnetic waves by Langmuir ones
taking into the account the electric drift motion of particles, is the most
intense nonlinear process and should be responsible for the formation of
radiation spectrum of radio pulsars. Performed analysis indicates that in the
case of existence of inertial interval formation of stationary spectra is
possible. Analysis of linear mechanisms of wave generation and silk allows to
conclude that only possible stationary solution has spectral index $\alpha
=-1.5$. Obtained spectrum is in good agreement with observational data.
