[evlatests] Super-Birdie in Ka-band

[Rick Perley]

    The whopping great birdie seen at 29440 MHz is still present in the 
new 'RFI Sweep'.  It is visible on all baselines, and both polarizations 
-- and is strong enough to be easily seen in the autocorrelations.  It 
is not strong enough to 'collapse' the subband (meaning it contributes 
no more than comparable power to the receiver noise within the 128 
MHz-wide subband). 
    It is much stronger on some antennas than others.  In RCP, the 
dominant antennas are 8, 12, 15, 24, and 27.  It is notably weak on 
ea18.  However, the picture is quite different in LCP ... 
    This birdie is not part of a comb structure.  Ken showed earlier 
this year that it is due to a 2nd harmonic of an LO. 
    Can we get rid of this?