[evlatests] Next test ...

[Rick Perley]

    For this test, the cables feeding the samplers from the T304 modules 
were interchanged, so that the output RR correlations are in fact the 
LL, and vice versa.  If the problem lies 'upstream' of the swap, the 
noise asymmetry should change polarization.  If the problem lies 
'downstream' from the swap, the noise asymmetry should remain the same. 

    The higher noise remains on the RCP side.  From this we conclude 
that the added noise problem is introduced between the analog input to 
the sampler, and the digital input to the correlator station board. 

    That's all we can do today.  We'll pick this up again on Tuesday 
morning. 

    Below I give the 'noise matrix', (for the record):

         15          22         27          28
----------------------------------------------
15   |   X         .23        .23         .21
22   |  .19         X         .26         .23
27   |  .20      .19           X          .23
28   |  .20      .19          .20           X

Observant readers may note that the difference between RCP and LCP is 
not so great in this test as it
was in the others -- this may be due to different sensitivities between 
the RCP and LCP, or it may be telling us something more subtle ...


-------- Original Message --------
Subject: 	thirs installment of swapped data
Date: 	Fri, 3 Sep 2010 16:21:09 -0600 (MDT)
From: 	Ken Sowinski <ksowinsk at aoc.nrao.edu>
To: 	Vivek Dhawan <vdhawan at aoc.nrao.edu>, Rick Perley 
<rperley at aoc.nrao.edu>



This time we have swapped the cables at the input of the D301
sampler module.  The observation is C3noise_001.

2148  Start script
2158  Finish gain adjustments
2218  Stop script