[evlatests] Temperature-Dependent Gains at P-band...

[Rob Long]

I looked to see if this had anything to do with the new aluminum 
heatsinks vs the brass ones. Two of the 4 are the old brass ones and two 
are aluminum. Better than half of the array has aluminum heatsinks now 
so I don't see a connection there. Curious...

Rob

On 2/14/2019 11:18 AM, Rick Perley wrote:
> Indeed -- but hard to understand how that would translate into an 
> unusual temperature sensitivity ...  The observations were mostly at 
> night, with ideal weather conditions...
>
>     Antennas 1, 2 and 24 were adjacent (W6, W4 and W8 respectively), 
> while ea28 was down the arm a bit, at W14.
>
>     Rick
>
>
> On 02/14/2019 11:05 AM, Dan Mertely wrote:
>> Hi Rick. I notice that all 4 antennas referenced are on the
>> west arm.  -Mert
>>
>> On 2/14/2019 9:07 AM, Rick Perley wrote:
>>>      In reviewing the data from the lunar polarization experiment, I 
>>> note that some antennas have a very strong temporal variation in 
>>> their gains.  These changes are as large at 75%, are quite slow, and 
>>> seem highly correlated with temperature -- for all the affected 
>>> antennas, the maximum gain occurred at ~6AM, when temperatures were 
>>> coldest.
>>>
>>>      The most strongly affected antennas are:
>>>
>>>      ea02 (max/min power ratio = 1.75)
>>>
>>>      ea01 (1.50)
>>>
>>>      ea24 (1.40)
>>>
>>>      ea28 (2.0 -- although the time dependency for this one is not 
>>> the same as the others).
>>>
>>>      For all, the rise and fall of the power is gradual.  And for 
>>> all, the switched power values seem to perfectly track the gain 
>>> changes (as they should!).
>>>
>>>      Why should these antennas be (apparently) temperature 
>>> sensitive, while the others are not?
>>>
>>>      Rick
>>>
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>>
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