  The aim of the present analysis is to improve the knowledge of the
statistical properties of the Galactic diffuse synchrotron emission, which
constrains sensitive CMB anisotropy measurements. We have analysed the new DRAO
1.4 GHz polarization survey together with the Stockert 1.4 GHz total intensity
survey and derived the angular power spectra (APSs) of the total intensity, the
polarized emission, and their cross-correlation for the entire surveys and for
three low-intensity regions. The APSs of the diffuse synchrotron emission are
modelled by power laws. For the $E$ and $B$ modes, a slope of $\alpha \sim
[-3.0,-2.5]$ for the multipole range $\sim [30,300]$ is found. By the
extrapolation of these results to 70 GHz, we can estimate the Galactic
synchrotron contamination of CMB anisotropies, and we find results that are
compatible with the ones coming from WMAP 3-yr data. In the low-intensity
regions, the cosmological primordial B~mode peak at $\ell \sim 100$ should be
clearly observable for a tensor-to-scalar ratio $T/S \gsim 0.5$ and a
synchrotron temperature spectral index $\beta \sim -3$. Its detection is also
possible for $T/S \gsim 0.005$ and $\beta \sim -3$, in case a separation of the
foreground from the CMB signal could be achieved with an accuracy of $\sim
5-10%$. For the TE mode, a mask excluding $|b_{gal}| \le 5^{\circ}$ (for
$\beta\sim -3.0$) or $|b_{gal}| \le 20^{\circ}$ (for $\beta\sim -2.8$) from the
surveys is sufficient to render the foreground contamination negligible, thus
confirming the ability of WMAP to have a clear view of the
temperature-polarization correlation peak and antipeak series.
