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Hi Rick,<br>
<br>
I looked at the archive data for the X-band, and also didn't see any
large temperature changes inside and outside the receiver. However,
the 15K stage temp change, while small, does appear to correlate
quite well with your plot, even with the coarse resolution of the
monitor data. I've attached this monitor data.<br>
<br>
-Wes<br>
<br>
<div class="moz-cite-prefix">On 1/19/2016 3:10 PM, Rob Selina wrote:<br>
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<blockquote
cite="mid:F7588D6775F97A4B87E49B51AD6AD7E14E997E@cvxsa.ad.nrao.edu"
type="cite">
<pre wrap="">Hi Rick,
No obvious issues with HVAC, plots attached for Sunday.
Mapping of monitor points courtesy of Jerry Langevin:
P301-1-EXT2 > Vertex Room Ambient
P301-1-EXT1 > LO/IF Rack, between door and modules.
P301-2-EXT1 > LO/IF Rack, Input plenum
P301-2-EXT2 > LO/IF Rack, Exhaust plenum
P302-1-EXT1 > Utility Rack, above D301
P302-1-EXT2 > Utility Rack, above D303
Any other suggestions to look into?
Cheers,
Rob
-----Original Message-----
From: evlatests [<a class="moz-txt-link-freetext" href="mailto:evlatests-bounces@listmgr.nrao.edu">mailto:evlatests-bounces@listmgr.nrao.edu</a>] On Behalf Of Rick Perley
Sent: Tuesday, January 19, 2016 2:10 PM
To: <a class="moz-txt-link-abbreviated" href="mailto:evlatests@aoc.nrao.edu">evlatests@aoc.nrao.edu</a>
Subject: [evlatests] ea20 gain variations
I noted last week how the switched power system nicely corrects gain changes at X-band.
In another 'beam holography' run, taken Sunday evening at 6cm, the same type of gain variations noted earlier in ea20 at X-band are present in that antenna at C-band. I attach a plot of the 'PDif' values. The gain variations are significant -- about 10% in power. The timescale is about 1 hour.
I would guess that something is quite amiss with the temperature control, since this behavior is seen on (at least) two different bands.
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</pre>
</blockquote>
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