[evlatests] Phase stability of ea27 {External}

[Drew Medlin]

I updated the Jira ticket with a note saying I saw about a 24hr period with some instances of ea27 showing phase jumps for L and C band May 08-09, then I don’t see more notes from our pipeline records about it until June 6 for PI science, then some in VLASS. The C band data were 3bit. 



Drew Medlin		
dmedlin at nrao.edu

VLA Scientific User Support
National Radio Astronomy Observatory

> On Jun 30, 2023, at 11:25 AM, Rob Long via evlatests <evlatests at listmgr.nrao.edu> wrote:
> 
> If we have a loose connection between the L300 and LO or DTS splitters, something like this could occur. Do we see this effect in both 8-bit and 3-bit?
> 
> Rob
> 
> On 6/30/2023 11:22 AM, Rick Perley via evlatests wrote:
>> following up on Bryan's point:  The changes were by many tens of degrees on a timescale of 10 minutes.  It was stable within the calibrator scan, then hopped to an entirely different number 10 minutes later ...
>> 
>> No way a baseline error can do that...
>> 
>> Rick
>> 
>> On 6/30/23 11:04, Bryan Butler wrote:
>>> 
>>> It's a good point, but that wouldn't cause the behavior that Rick sees. It would cause a diurnal sinusoidal error which got worse with higher frequency, not random amounts for all bands, and changing between scans.  Seems like a loose connection maybe?  But would have to be after the converters.
>>> 
>>>     -Bryan
>>> 
>>> 
>>> Catarina Ubach via evlatests wrote on 6/30/23 10:48:
>>>> Antenna 27 baselines parameters have not been updated.
>>>> 
>>>> Catarina
>>>> 
>>>> -----Original Message-----
>>>> From: evlatests <evlatests-bounces at listmgr.nrao.edu> On Behalf Of Rick Perley via evlatests
>>>> Sent: Friday, June 30, 2023 10:09 AM
>>>> To: evlatests at aoc.nrao.edu
>>>> Subject: [evlatests] Phase stability of ea27
>>>> 
>>>>   From data taken last night, it is noted that ea27's phase changes by large, and seemingly random amounts at all bands observed (L, S, C, X, and Ku).  This occurs between scans, and is not seen on other antennas.
>>>> 
>>>> Rick
>>>> 
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