[evlatests] ea22 -- something weird

[Rob Selina]

Hi Rick, 
There was a problem with EA22's HVAC system at that time. Monitor data plot attached. 
Cheers, 
Rob


-----Original Message-----
From: Rick Perley [mailto:rperley at aoc.nrao.edu] 
Sent: Thursday, May 19, 2016 3:02 PM
To: Rob Selina <rselina at nrao.edu>
Subject: Re: [evlatests] ea22 -- something weird

     January 25

On 05/19/2016 03:01 PM, Rob Selina wrote:
> Hi Rick,
> What was the date of your observation?
> Cheers,
> Rob
>
>
> -----Original Message-----
> From: evlatests [mailto:evlatests-bounces at listmgr.nrao.edu] On Behalf Of Rick Perley
> Sent: Thursday, May 19, 2016 12:55 PM
> To: evlatests at aoc.nrao.edu
> Subject: [evlatests] ea22 -- something weird
>
>       I'm finally reducing the January 'flux density/calibrator model'
> data.  Because part of the goal is to link the flux scales to the 'known' source Cygnus A, I cannot apply the switched power (due to the infamous 'PDif Compression' issue).
>
>       Thus, I can easily see the gain changes induced the the diurnal temperature variation.  At 6cm, the effect is remarkably large -- about 4% in power, peak-peak.
>
>       But one antenna stands out -- ea22 has a 25% (!!!!!) diurnal variation (at 6cm -- I haven't yet reviewed the higher frequency data).
> The pattern is exactly the same as all the other antennas, but is about
> 6 times stronger effect.
>
>       So the question is:  What is (or was) different about the temperature control in this antenna?
>
>
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