[evlatests] Antenna 13, continued

[Rick Perley]

    To add a bit to Barry's previous message:

    The idea was to use an EVLA-only subarray to do pointing at 6cm,
in order to determine antenna 13's offset.  We got a single pointing
solution yesterday, using 3C84, showing antenna 13 was pointing at
least 5 arcminutes off.  (It's remarkable that the system was able to
determine this, as that is more than the HWHP, and it's well known
the automated pointing doesn't do well that far off). 

    As Barry noted, it was quickly discovered that an EVLA-only
subarray records no data.  A single VLA antennas was taken from
the science array, and the system at least recorded data for analysis.

    However, antenna 13 provided no pointing solutions (although
14 and 16 did).  So, we went to L-band, presuming the trouble was
a very large pointing error. 

    But this wasn't successful either, as the amplitudes seen from antenna
13 were too low.  (The Modcomps pointing program has an amplitude
cutoff).  At this point, Barry was called into see if there was a simple
solution.  He sent his report earlier.  In short -- delays are o.k.  
Pointing
is uncertain.  The AC IFs have a phase wind.  BD IFs don't.  (For Ant 13). 

    We're confused. 

    I have 3 hours' test tomorrow afternoon, and another 2 hours Sunday
morning.   If anybody has a good idea for good use of this time, let me 
know.