  We study the influence of the propagation effects on the mean profiles of
radio pulsars using the Kravtsov-Orlov method of the wave propagation in the
inhomogeneous media. This approach allows us firstly to include into
consideration the transition from geometrical optics to vacuum propagation, the
cyclotron absorption, and the wave refraction simultaneously. In addition,
arbitrary non-dipole magnetic field configuration, drift motion of plasma
particles, and their realistic energy distribution are taken into account. The
one-to-one correspondence between the signs of circular polarization and
position angle (p.a.) derivative along the profile for both ordinary and
extraordinary waves is predicted. Using the numerical integration we now can
model the main profiles of radio pulsars. It is shown that standard S-shape
form of the p.a. swing can be realized for small enough pair production
multiplicity and large enough bulk plasma Lorentz factor only. It is also shown
that the value of p.a. maximum derivative, that is often used for determination
the angle between magnetic dipole and rotation axis, depends on the plasma
parameters and could differ from the rotation vector model (RVM) prediction.
