[evlatests] Strange X-band birdie

[Rick Perley]

    And Ken is right!  It is indeed at 8192 MHz (apparently I can't do 
simple arithmetic). 

    I reviewed all 351 cross-power spectra, and confirmed that the 
birdie is seen only on baselines amongst the antennas listed below, and 
that it is strongest *by far* on baselines with antenna 16.  Start 
investigating with that one!



Ken Sowinski wrote:
> On Wed, 15 Sep 2010, Rick Perley wrote:
>
>>    The X-band HercA data have shown an odd birdie, not previously known
>> to me.
>>
>>    All four IFs show a strong, unresolved (2MHz wide channel) birdie at
>> 8188 MHz.  But it's visible only on antennas 13, 16, 19, and 26.  Of
>> these, it is, by far, strongest on antenna 16.
>
> 8192 is a multicple of 4096 and all its sub-harmonics.
> Any chance you are off by two channels?