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<p>This looks off to me. I'll talk to my team tomorrow.</p>
<p>Rob<br>
</p>
<div class="moz-cite-prefix">On 9/18/2024 3:34 PM, Ephraim Ford via
evlatests wrote:<br>
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<p class="MsoNormal">This looks about the same as the photo I
took, just from the different direction.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b>From:</b> evlatests
<a class="moz-txt-link-rfc2396E" href="mailto:evlatests-bounces@listmgr.nrao.edu"><evlatests-bounces@listmgr.nrao.edu></a> <b>
On Behalf Of </b>George Moellenbrock via evlatests<br>
<b>Sent:</b> Wednesday, September 18, 2024 2:02 PM<br>
<b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:evlatests@listmgr.nrao.edu">evlatests@listmgr.nrao.edu</a><br>
<b>Subject:</b> Re: [evlatests] P-band Dipole Orientations
{External}<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p>Hi Rick, Rob-<o:p></o:p></p>
<p><o:p> </o:p></p>
<p>Climbed ea11 today with some visitors, and mused about the
P-band dipole orientation. FWIW...<o:p></o:p></p>
<p><o:p> </o:p></p>
<p>Get out your protractors:<o:p></o:p></p>
<p><o:p> </o:p></p>
<p><img style="width:20.2291in;height:25.1111in" id="Picture_x0020_1" src="cid:part1.y3vfk5u4.sm8u6IQg@nrao.edu" class="" width="1942" height="2411"><o:p></o:p></p>
<p><o:p> </o:p></p>
<p>Notwithstanding Rob's assertion below (about ea11), the above
looks a tad off-set clockwise-ward (looking up at it),
relative to the quad legs. Of course, I'm not looking
straight up from the center of the dish, and it was
best-efforts aligning myself with the quad legs (and the sun
was bright!). I'm not sure this looks like as much as 10
deg (as Rick reports), but it is easily 5 deg, I think, and
Rick's measurement would be consistent with ea01 being at -5
deg (and Rob's assertion that ea01 is a bad reference), and
most of the others in his table would be closer to zero. Of
course, there are 20+ other antennas that are well-aligned
with ea01...<o:p></o:p></p>
<p><o:p> </o:p></p>
<p>Cheers,<o:p></o:p></p>
<p>George<o:p></o:p></p>
<p><o:p> </o:p></p>
<p><o:p> </o:p></p>
<p><o:p> </o:p></p>
<p><o:p> </o:p></p>
<div>
<p class="MsoNormal">On 9/18/24 11:43, Rob Long via evlatests
wrote:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p>Hi Rick,<o:p></o:p></p>
<p><o:p> </o:p></p>
<p>It looks like our main dipole culprit is ea01. The dipole
itself is not orthogonal (elements twisted) and we are going
to have to get with the mechanics to get it removed so we
can align it or install the spare.<o:p></o:p></p>
<p><o:p> </o:p></p>
<p>ea11 (on the other hand) looks to be aligned well (if you
wanted to use it as a reference).<o:p></o:p></p>
<p><o:p> </o:p></p>
<p>Rob<o:p></o:p></p>
<p><o:p> </o:p></p>
<p><o:p> </o:p></p>
<div>
<p class="MsoNormal">On 9/10/2024 3:43 PM, Rick Perley via
evlatests wrote:<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">Ther
results of a polarization calibration of a recent
P-band dataset (obtained via VLITE) indicate a
significant number of antennas with apparently
misaligned feeds. <o:p></o:p></span></p>
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<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black"><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">As
this was a VLITE database, there were only 18 antennas
included, one of which was out of service. For the
seventeen others, the calibration shows seven antennas
misaligned by more than 5 degrees w.r.t. the reference
dipole (ea01). They are:<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black"><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">ea17 5.7
degrees<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">ea07 8.6<o:p></o:p></span></p>
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<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">ea11 10.3<o:p></o:p></span></p>
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<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">ea20 5.7<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">ea23 5.2<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">ea27 8.0<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">ea21 8.6<o:p></o:p></span></p>
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<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black"><o:p> </o:p></span></p>
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<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">It
is my impression (but I do not have the data in hand
to prove it) that this is worse than what was seen a
few years ago. <o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black"><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">These
misorientations should be easily visible from the
antenna surface. It would be good to know if visual
inspection agrees with the observations. <o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black"><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">Rick<o:p></o:p></span></p>
</div>
<p class="MsoNormal"><br>
<br>
<o:p></o:p></p>
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