[evlatests] EVLA tests of Sept 7

[Pat Van Buskirk]

As has been noted, antenna 14 was not communicating and 16 seemed to be
working at the end of Wednesday's work day. The operator confirmed this
via the acu screens. Ken instructed the operator to include both 14 and
16, stating that it would be ok that 14 was not working. Steve put both
antennas into sub1 and ran obs2script to convert Rick's VLA file.

Both antennas were parked and being monitored prior to the test. Steve
started the EVLA script, then put the antennas into digital position
mode. 14 didn't respond; 16 immediately went to the first source, then
kept going down in elevation. Steve tried various options: "Stow" caused
the antenna to go out of dpm; "Track" turned dpm back on. He tried to
put the antenna on standby, but it had already reached the elevation limit.

Per the instructions in Rick's file, at 9:55 pm, Steve called Ken, who
was unable to help and asked Steve who else he could call to make the
antenna work. Steve then called Tom Frost to get the antenna out of the
elevation limit. Approximately 40 minutes later, the antenna stowed
itself and corrected the elevation limit; this is why Tom Frost did not
see the antenna in the limit when he arrived. Steve could not cancel the
call to Tom, believing he was on his way in.

I hope this helps with some of the confusion surrounding the test.
Please let me know if you have any questions or if we can be of any
further help.

Cheers,
Pat





Rick Perley wrote:

>    I had 2.5 hours scheduled test time last evening.  The intention was 
> to do sensitivity
> and stability tests of antennas 14 and 16 at L, C, X, and K bands.
>    A sign of trouble appeared just before 5PM, when it was reported by 
> numerous
> individuals that antenna 14 was non-responsive.   A final email from Jim 
> Jackson
> postulated a problem in the fiber network.
> 
>    But antenna 16 was reported as functional, with at least 2 IFs 
> nominally working,
> so it was decided to continue with the run.
>    No useful data from either antenna were obtained.  The operator log 
> reported
> that both 14 and 16 were 'in elevation limit'.  A later note recorded 
> that  Tom Frost
> was called out.
>    Can anybody explain how a perfectly good Observe file can drive the two
> EVLA antennas into their elevation limit?  (All the VLA antennas worked
> normally).
>    It would be very useful to recover these two antennas, so part of 
> today's
> software time can be used to do these tests.
>    Rick
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-- 
Were it offered to my choice, I should have no objection to a repetition
of the same life from its beginning, only asking the advantages authors
have in a second edition to correct some faults in the first.

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