[evlatests] L and C band sensitivity

[Rick Perley]

    Finally, a short note on Sensitivities at L and C bands, taken from
spectral line data from Saturday night.  These are based on the
aipsweights. 

    The source was at an elevation of 29 degrees.  EVLA antennas should
be better than VLA antennas at this elevation. 

    Below, I give the *rank* of the antenna sensitivity (with '1' 
meaning it's
the best), for each band for each IF.   There were 26 antennas in the array.

                   L-Band (AC = 1465, BD = 1385 MHz)

    Antenna      A      B      C      D
--------------------------------------------
       13            24      7      msg    1
       14            13      1      4        3
       16            25      9      19     12
--------------------------------------------------
****************************************************
                   C-Band  (AC = 4885, BD = 4835 MHz)

    Antenna      A      B      C      D
--------------------------------------------------
       13            13      5      14      7
       14              2      1        1      2
       16              8      2      26     20
---------------------------------------------------------------

    I'm somewhat at a loss to explain these odd results.  Only
antenna 14 is where it should be (except for IF A at L-band).  In 
particular,
the sensitivities for A should be similar to B, as should be C and D.  For
the VLA antennas, this is generally true. 
    I'd like to blame the messenger (i.e., the aipsweights can't be 
trusted),
but have no evidence for doing so.  Certainly, for VLA antennas, the
aipsweights have been shown to be a reliable indicator of real antenna
sensitivity.  But perhaps the situation for the EVLA antennas is different.
Certainly, the recorded system temperatures are not trustworthy -- they
continue to change from day to day in a way that doesn't look real to
my eye.  We should perhaps be tracking these values more carefully.