[evlatests] Phase vs. elevation; phase jumps.

[Vivek Dhawan]

This is a re-post of what I sent yesterday - for some reason the mail
system did not distribute it.

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Results from the 'baseline' run, Nov 27, X-band, 5 hours.

Phase variation with elevation:

       EA 13, 14, 16 still cannot fit an improved position.

       EA 23: only one IF, A. Amplitudes about 50% or lower.
              and phase vs. el. worse than the others.

       EA 26 (Durand was particularly interested) worked pretty
             well - fringes of the right strength on all 4 IFs.
             Phase vs. elevation is poor - like many EVLA antennas.

       EA 18 and 24: continue to behave well re phase vs. elevation.
             But see next item.


Phase jumps:

            There are 3 occasions when the phase jumps by over 100
            degrees, then jumps back again several minutes later.
	   The jumps are on all IFs, and are very clear on 18, 24.
            They are partly masked by the elevation variation on
            13, 14, 16; and completely masked on 23 and 26.

            The data are consistent either with all EVLA antennas
            OR all VLA antennas having the jump.

Vivek.