[evlatests] ea24 problem

[Rob Long]

Pointing and sub-reflector were asked about right away. How did we 
determine it was OK at first?

Rob

Ken Sowinski wrote:
> On Fri, 4 Mar 2011, Emmanuel Momjian wrote:
> 
>> Yesterday, test observations at Ku-band showed noisy phases and amplitudes
>> on ea24. To look into this in more detail, today we ran multi-frequency
>> observations spanning all the bands from X to Q using the calibrator
>> J2202+4216 .
>>
>> While there is nothing obvious at X-band, the data show that the phases and
>> the amplitudes degrade progressively from Ku to Q band.
>>
>> Pointing looks OK on ea24. Therefore we think that the problem may be in the
>> L301 or its reference signal, although L302 and the round trip phase look
>> good.
> 
> The problem was just found to be focus.  The focus zero point changed
> by about 2 cm sometime last week.  I have adjusted the focus settings
> for all the high frequency bands as well as X and C bands.  A more
> careful measurement will be made in the next day or so.
> 
> _______________________________________________
> evlatests mailing list
> evlatests at listmgr.cv.nrao.edu
> http://listmgr.cv.nrao.edu/mailman/listinfo/evlatests