[evlatests] miscellaneous observations

[Ken Sowinski]

Barry reported this morning that VLA antennas did not setup at
the first scan of a script.  I found no problem with this when
the operator was running things.  We switched between bands
many times and all antennas did the right thing every time.
When I ran an executor first scans did not always work right.
Perhaps different executors interact differently with the CMP?

I took advantage of this to see that all the antennas worked.
No attempt was made to track down causes of the probelms listed.
23 and 19 were out of service for much of the time.

L band
Many IFs seemed to work poorer than expected:
4D, 14 all IFs, 16B, and 21AB.

C band
16 ABD (but not C) were not working and there appeared to be
no power getting to the downconverters.
19 was very weak.  It might well need delays or pointing.

K and Q bands
14AC was dead.

X band
Everything worked!


P band.
17BD needed some attenuator adjustments.
4 doesn't seem to work. no SD and no TP in some IFs.
14AC was dead.
11 was quite weak with the same power in all polarization products.
Broken dipole or hybrid?

Never got to 4 band.


Antenna 23
Something weird is happening here.  I heard it was truck by lightning
last week.  Pointing was way off today when the antenna became available.
L band data suggested a pointing error of about a degree.
Moving the subreflector by a lot made each band work, however the offset
at each band was different.  That suggests a pointing error, but there
seemed to be no error pattern.

The subreflector has been worked on for several days now so that is
the leading culprit based on the rule that the last thing touched
must be what is broken.  If examination shows up no problems the
next step is to try to find the pointing offset at L band and then
see if the same offset works for C or X bands.