[evlatests] More on noise for mode 'PA'

[George Moellenbrock]

> I then remembered that I had taken data in mode 'PA' for observations of
> 3C273, back in 1997, with the same BW (12.5 MHz) as the recent tests.  I
> have loaded these data, and did a quick calibration.  The result of this
> is that there is *no* difference in the noise, as shown by the histrogram
> distributions in real and imaginary parts, of the four correlations.
>
> Thus, it appears that this problem is a relatively recent development.
>

Among the most recent of my mode 'PA' instr pol stability and freq-dep 
tests was an observation in Mar 2006.  In that observation (15ch, L-band), 
the noise in the cross hands and parallel hands appears to be the same (I 
am examining the calibrated data).  So I concur with Rick that the problem 
is a "relatively recent" development (though my definition of "relatively" 
is a little different than his...), i.e., the problem was introduced AFTER 
Mar 2006.

-George