[evlatests] VLBI at the EVLA test report

[Ken Sowinski]

The surprising failure reported here is that the VLA antennas failed
to phase; I expected this to work.  A diagnostic would be to look
at the time behavior of the phases.  If they are wrong and constant
then we are not trying at all to correct the phase or antsol is not
providing gain solutions for those antennas.  If they are wrong and
changing then we are applying the phase correction improperly, either
wrongly scaled or with the wrong sign.

The reference antenna choice is interesting because we are used to
allowing the operator control over this with the ability to change
reference antenna as whim or necessity dictate.  Embedding the
choice in the script makes the it static unless we allow someone
to edit the script and restart it.  Maybe a something like 
subarray.setRefant() needs to be made available to the operator.
I have suggested the need for a "front panel" interface for the
VLA before and this is an example of a use for it.

Once the problems Walter noted with Y1 are addressed we should find
time for another go at testing it, even without phased array support.