  On the basis of the unified model of compact radio sources, the dependence of
a turnover frequency in the smoothed radio spectrum of a pulsar upon the ratio
of the dispersion measure to the period of a pulsar is obtained. This relation
is produced by the radial density wave in the accretion disk surrounding a
pulsar. The unified model of compact radio sources gives also the smoothed
spectral indices of radio emission from pulsars as $\alpha=2$ for the gaseous
disk with the temperature profile T=const and $\alpha=3$ for the gaseous disk
with the pressure profile P=const ($F_{\nu} \propto \nu ^{- \alpha} $).
