[evlatests] Global Phase Jump

[Rick Perley]

The subject was in the singular, for a reason ...

I ran my favorite phase-jump-inducing file today, a main-beam holography 
file, which makes the antennas change position every ten seconds, for a 
little over one hours -- about 360 source changes. 

The file used five different bandwidths, and five different Fluke 
settings, arranged to the center frequency was always the same.  X-band 
default frequencies were used.

All 6 EVLA antennas performed magnificently. 

Result:

No phase jumps of any kind within any scan were found! 

A ~100 degree change in phase, for all EVLA antennas w.r.t a VLA 
reference antenna, was found at the 50 MHz BW setting, between two 
calibrators observed nearly an  hour apart.  Between these two 
observations were the 25, 12.5, 6.25 and 3.125 MHz BW observations -- 
and there were no phase jumps seen in any of these. 

Things get better and better -- but why???