[evlatests] EVLA phases still jumpy.

[Vivek Dhawan]

Three things were tried:

1. reboot CMP and 2. re-start executor. The jumps continued.

3. Re-synch a few antennas (4,11,25). Still jumpy on all.

So no progress today. Maintenence day tomorrow, any fresh ideas
to sacrifice? I offer one at the end.

There are actually 2 problems:

1. Phases and amplitudes are steady and strong for many 10's of
minutes, but jump to a new value on all EVLA antennas together.
The jumps may be different magnitudes on each antenna. EVLA-EVLA
baselines only are affected, VLA-VLA unaffected. This problem
is ongoing, but stretches of hours may have no jumps.

2. Some projects (nothing extraordinary, standard continuum and
line 25MHz both have been seen) have an additional problem where
the fringes on many, not all, EVLA-EVLA baselines are weaker than
on VLA-VLA ones. This problem is not present in every project.

I dont know if there is a single cause for these 2 woes, but
there may be a clue: Sometimes when the phase jumps off on a
given EVLA antenna, its fringes get weaker - could its delay
or Walsh synch be off at that time? A line observation would
show a delay offset, I'll try that at the next opportunity.