[evlatests] Global phase jumps again.

[Vivek Dhawan]

To see if EA 14 phase was fixed after its hardware work, I
looked at AH942 observed on Sep 15 night.

14 is now no worse than any EVLA antenna (but this is K band data).

The report below was sent last Friday, and still pertains:

AH942 K band continuum.

Global phase jumps are back - There is a reference pointing scan
(X band) every hour, and bad things happen almost every time:

Antenna 4 has short phase glitches (but returns to the same phase)
at those times. 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 totally
incoherent) on IF C only.

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