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All:<br>
<br>
Tomorrow is the 2nd Thursday of the month, hence time for the
monthly 'test results' meeting. So that will 10AM, 08 May, in Rm
317. <br>
<br>
There is little new to present, so Keith and I would like to
have a short meeting to discuss what tests can and should be done
over the next few months. The goal is to get a sense of what the
priorities should be for testing over the summer months. <br>
<br>
We with to limit the discussion to antenna and electronics
testing. Specific correlator testing should be discussed
separately. <br>
<br>
Some off-the-cuff topics include:<br>
<br>
1) Switched power effectiveness, including 'PDif' and 'PSum'
issues, and the values of Tcal. <br>
2) Further 3-bit testing, including methods to correct for the
large 'PDif' compression that occurs in that mode (and which is
probably separate from that which affects the 8-bit sampling mode).<br>
3) Elevation gain functions<br>
4) Antenna optics -- in particularly the efficacy of the
'subreflector rotation trick'. ea15 and ea18 are different than
all the rest (at present), and ea20 is just plain weird. <br>
5) Beam holography at L and S bands (and any other band). <br>
6) Surface holography at P-band (and any other band). <br>
7) New ACU tests.<br>
8) Temperature stabilization of the noise diodes. <br>
9) 5 MHz comb power (at 4-band)<br>
<br>
Please bring your own lists, if different than above. <br>
<br>
Rick<br>
<br>
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-------- Original Message --------
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">Subject:
</th>
<td>Re: New EVLA things to worry about: a List</td>
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">Date: </th>
<td>Fri, 02 May 2014 14:07:19 -0600</td>
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">From: </th>
<td>Keith Morris <a class="moz-txt-link-rfc2396E" href="mailto:kmorris@aoc.nrao.edu"><kmorris@aoc.nrao.edu></a></td>
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">Organization:
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<td>NRAO</td>
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">To: </th>
<td>Ken Sowinski <a class="moz-txt-link-rfc2396E" href="mailto:ksowinsk@nrao.edu"><ksowinsk@nrao.edu></a></td>
</tr>
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">CC: </th>
<td>Jim Jackson <a class="moz-txt-link-rfc2396E" href="mailto:jjackson@nrao.edu"><jjackson@nrao.edu></a>, Rick Perley
<a class="moz-txt-link-rfc2396E" href="mailto:rperley@nrao.edu"><rperley@nrao.edu></a></td>
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<pre>> Other stuff that comes immediately to mind involves testing/verifying
> yet unused correlator capabilities. I don't think that is what you
> want for this list.
Do those include "Y1" mode? Vivek had mentioned doing an ea20-PT
baseline, but I believe it would require an as yet unavailable
correlator mode.
On 5/2/2014 9:56 AM, Ken Sowinski wrote:
> These seem to be mostly 'old' things.
>
> On Fri, 2 May 2014, Keith Morris wrote:
>
>> Here are some of the issues that Rick, Jim and I thought should be on
>> our list of things to worry about:
>>
>> 1. Switched power compression
>> 2. Thermal effects in switched power
>> 3. Polarization phase (and its possible connection to switched power)
>
> I suppose this means that variations in pol phase and switched power
> may have a common cause?
>
>> 4. 3-bit-specific switched power
>> 5. New ACU testing (qualification, specifications, etc)
>> 6. Antenna optics & gain curves, namely ea15, ea18, and ea20
>>
>> Add other items to the list as necessary. And if anyone would like to
>> elaborate on what is known or unknown about these, that could help
>> form a basis for designing and prioritizing tests.
>
> Not very important, but it comes to mind because of recent coversations.
> 7. Investigate the "5MHz comb" seen in the 75 MHz band. Two parts:
> decide whether it is strong enough to care about; and if so is there
> any easy (cheap) mitigation.
>
> Other stuff that comes immediately to mind involves testing/verifying
> yet unused correlator capabilities. I don't think that is what you
> want for this list.
>
> Ken
>
</pre>
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