[evlatests] More on X-band delays, and conventions ...

[Rick Perley]

    Eric and I peered into the X-band database provided by Michael to 
test the sky orientation.  Recall that I reported earlier that the 
delays calculated by FRING, when applied to the data through CLCAL, 
seemed to double the delay phase slope, rather than remove it.

    The situation is in actuality, a little different.  By careful 
viewing of the 3-subband spectra, and relying on the previously 
established characteristic that phases connect smoothly across subband 
boundaries, we are quite certain that the problem is that subbands 1 and 
3 are interchanged.  This will mightily confuse FRING, causing further 
downstream confusion. 

    The problem doesn't affect the imaging tests done today, as BPASS 
was run (without using the incorrect delays) and applied.  This 
operation removes phase slopes without any reference to subband ordering.