  In this paper we report the results of electrical resistivity (1.5K < T
<300K) and point contact spectroscopy (PCS) measurements on single crystals of
metallic sodium tungsten bronze with varying sodium content. We have shown that
the electron-phonon coupling function as measured through PCS can explain
quantitatively the large temperature dependence of resistivity $\rho$ seen in
these materials over the entire temperature range. The electron-phonon coupling
function shows predominatly large peaks for phonon frequency range of 30meV <
$\omega$ 100meV which match well with the calculated optical phonon modes for
WO$_6$ octahedra. The integrated electron-phonon coupling constant $\lambda$
from this data is $\approx$ 0.25-0.45.
