[evlatests] Slow Wobbles -- a suggested antenna move

[Barry Clark]

Actually, the next couple of diagnostic steps are pretty location
independent.
1.  Radiate a K band signal at the frequency of Rick's wobble
maximum plus and minus 128 MHz (we could tell whether it was plus
or minus by looking at the direction of the phase rotation, but
we'd probably get it wrong), and seeing if it shows up in the band
at the nominal frequency.
2.  Try swapping modules, T302, maybe D302, and seeing if the effect
moves.

On 01/28/2013 10:55 AM, Rick Perley wrote:
>      Our curious 'slow wobble' problem is known to be proportional to the
> 'u' coordinate, and is (by far) most strongly visible on the baseline
> ea02 to ea23.  These two antennas are adjacent on the north arm, on pads
> N6 and N7, which means that the 'u' coordinate on their baseline is very
> small.  This makes detecting the effect in visibility data very
> difficult as the timescales for the change are in tens of minutes.
>      I note that the pad W09 is currently empty.  Ea08 is scheduled to be
> moved there once the outfitting on the MasterPad is completed.  I
> suggest that either ea02 or ea23 be moved to W9, and ea08 be moved to
> the vacated pad.  This would provide us a baseline between ea02 and ea23
> with reasonably long value of coordinate 'u', to enable further testing
> of the 'slow wobble' effect.
>      Gene and Peggy are aware of this suggestion, and see no significant
> problems.  Does anybody else have an issue with this idea?
>
>
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