[evlatests] 1830 MHz birdie?

[Rob Long]

Hi Vivek,

The tests I ran on ea22 show that the sub-reflector has to be moving 
(focus or rotation) to cause the RFI. I don't know the exact nature or 
frequency of the RFI on ea22 yet.

Rob

On 3/25/2021 1:58 PM, Vivek Dhawan via evlatests wrote:
> Hi guys,
>
> I can take a look at L band today after test/maint is
> done. will let you know. Does FRM need to be moving for
> the purported signal to be seen or we just don't know yet.
>
> We did a recent sweep for checking if the operator's
> webcam made any RFI. I attach a plot from mar 11, pink=
> webcam on, green = off,unplugged. the 1830 is about  1.5-2MHz
> wide. stuff at 1785 is a mystery.
>
>
> On 3/25/21 1:39 PM, Rob Long via evlatests wrote:
>> Could this possibly be related to the L-band issue we have on ea22? 
>> We know there is a huge interference from the FRM drive on ea22. I 
>> don't think servo has been able to investigate yet.
>>
>> Rob
>>
>> On 3/25/2021 1:00 PM, rperley via evlatests wrote:
>>> In some recent observing at L-band, an ubiquitous RFI spike was 
>>> seen.  It is:
>>>
>>> - at 1830.0 MHz
>>> - is seen on most, if not all antennas
>>> - was present in every one of the 14 databases I have, all of which 
>>> were taken at night
>>> - seems to be spectrally unresolved
>>>
>>> It looks like an internal (or nearby) birdie.
>>>
>>> Can anybody suggest an origin?
>>>
>>> Rick
>>>
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