[evlatests] More on wobbles

[Rick Perley]

    Vivek has informed me of the very useful program FRPLT, which does 
an FT of the data. 

    Running this on the C and X-band data, it is easy to see that:

    A) The amplitude wobbles reported earlier have frequencies of 
precisely 2 and 4 Hz, are seen only in amplitude on baselines with 
antenna 27, only in LCP, and are independent of frequency.  All 
baselines show both 2 and 4 Hz, with the power in the latter being 
typically 3 times higher than in the former. 

    B) The reported phase wobbles are present in *both* amplitude and 
phase on only baseline 27 x 28, have a frequency which changes in time, 
and is proportional to sky frequency.