[evlatests] EVLA phases etc. Sep. 14th.

[Vivek Dhawan]

11 and 18 were reported to have phase jumps on IFs A,C and
Rob Long worked on them yesterday. To check if they were fixed,
I loaded calibrator data from 2 projects today.

Bottom line: 11 and 18 are indeed fixed. Other things went
awry and are confusing.


1. AH942 K band continuum, I looked at data 03:00 - 06:00 IAT.

No glitches are seen on 11 or 18.

However, global phase jumps are back  - antenna 4 had 4
short phase glitches (but returned to the same phase) about
equally spaced over the 3 hours. At those same times, All VLA
antennas show phase jumps between IF 1 and 2 (i.e. the A-B phase
and C-D phase jumps) - compared to any EVLA antenna. This
alone cannot indicate which array the jumps are on. BUT, in
addition, VA 12 and 22 show (IF1-IF2) phase jumps at those same
times, when compared to any other antenna (whether VLA or EVLA).
This to me indicates that the jumps are on the VLA and that
4, 12 and 22 are jumpier than the rest.

VA 15 had unstable amplitude and phase (noticable but not
incoherent) on IF C.

EA13 had very weak fringes - Ken told me about the FRM index
position being off so that is explained but needs fixing.


2. AH955, X and C band continuum.

11, 18 are fine. 15C is again a bit unstable. 4, 12 are jumpy.

X band - all fine (about 10 - 13:30 IAT)

C band - about 13:30 to 20:00. A bit like K band above -
          there are 3 jumps on VA 4 with respect to any antenna,
          EVLA or VLA. VA12 has jumps at two of those times. One
          of those times is also a global jump between EVLA/VLA -
          again I believe it is the VLA doing the jump. Again,
          the jump is easily seen in the Phase difference A-B or
          C-D.


V.