[evlatests] Antenna 8 cross-polarization at 6cm

[Rick Perley]

    C-band polarization observations made over the weekend using antenna 
8 (outfitted with the wideband OMT) show that this antenna has 
anomalously high polarization -- typically 10%, reaching 20% at the band 
edges.  This is much larger than any other wideband C-band antenna.  
Something is amiss.
    However -- the polarization is very stable, as it is with all other 
antennas.