  We present a deep, 8$\degr$ diameter, 0.4 GHz radio image using a first time
combination of the NAIC Arecibo 305-m telescope in Puerto Rico, and the
wide-angle interferometer at the Dominion Radio Astrophysical Observatory at
Penticton, Canada. Our observations are centered on the Coma Cluster of
galaxies in the ``Great Wall'' of galaxies near the North Galactic Pole. The
complementary nature of these two instruments enables us to produce a
distortion-free image that is sensitive to radiation on scales from 8$\degr$
down to that of an individual galaxy halo at the 100 Mpc distance of the Great
Wall. Newly revealed patches of distributed radio ``glow'' are seen well above
the detection limit. One prominent such area coincides with groupings of radio
galaxies near the Coma cluster, and indicates intergalactic IGM magnetic fields
in the range 0.2 to 0.4 $\mu$G on scales of up to $\sim$ 4 Mpc. Other patches
of diffuse emission, not previously explored at these high latitudes on
arcminute scales, probably contain Galactic ``cirrus''. A striking
anticorrelation is found between low-level diffuse radio glow and some regions
of enhanced optical galaxy surface density, suggesting that cosmological Large
Scale Structure (LSS), normally defined by the baryonic (or dark) matter
density, is not {\it uniquely} traced by faint continuum radio glow. Rather,
intergalactic diffuse synchrotron radiation represents IGM magnetic and Cosmic
ray energy density, instead of matter density. The diffuse, arcminute-level
structures over a large region of sky are potentially important pathfinders to
CMB foreground radiation on high multipole scales.
