[evlatests] EVLA Phase Stability

[Ken Sowinski]

On Wed, 24 Jan 2007, Rick Perley wrote:

>    Result #6.
>
> All EVLA antennas showed a strong phase drift with time, identical
> between polarizations, but very different between IFs (which were at
> 1465 and 1385 MHz for IFs 1 and 2, respectively).  The observed slopes
> are, w.r.t VLA antenna 2 (at the center of the array):
>
>    Antenna            AC               BD
> -----------------------------------------------
>    13                   -10 deg/hr       +16
>    14                   -27                     0
>    16                   -33                    +3
>    17                      0                   +27
>    18                    -7                    +20
>    23                    -10                  +20
>    24                   -67                   -60
>    26                   dead                -16
> ----------------------------------------------------
>
> No VLA antennas showed anything like this -- which is clearly not a
> baseline error.

This is a clear example of Vivek's two-turn-a-day phase drift.
What happened to antenna 24?  If that is not a typo and it is
trying to tell us what is happening I cannot read the message.