  We derive equations for the quasiclassical Green's functions $\check{g}$
within a simple model of a two-band superconductor with a spin-density-wave
(SDW). The elements of the matrix $\check{g}$ are the retarded, advanced, and
Keldysh functions each of which is an $8\times 8$ matrix in the Gor'kov-Nambu,
the spin and the band space. In equilibrium, these equations are a
generalization of the Eilenberger equation. On the basis of the derived
equations we analyze the Knight shift, the proximity and the dc Josephson
effects in the superconductors under consideration. The Knight shift is shown
to depend on the orientation of the external magnetic field with respect to the
direction of the vector of the magnetization of the SDW. The proximity effect
is analyzed for an interface between a superconductor with the SDW and a normal
metal. The function describing both superconducting and magnetic correlations
is shown to penetrate the normal metal or a metal with the SDW due to the
proximity effect. The dc Josephson current in an $S_{SDW}/N/S_{SDW}$ junction
is also calculated as a function of the phase difference $\phi$. It is shown
that in our model the Josephson current does not depend on the mutual
orientation of the magnetic moments in the superconductors $S_{SDW}$ and is
proportional to $ \sin \phi$. The dissipationless spin current $j_{sp}$ depends
on the angle $\alpha $ between the magnetization vectors in the same way
($j_{sp} \sim \sin \alpha $) and is not zero above the superconducting
transition temperature.
