[evlatests] More on Phase Wobbles

[Rick Perley]

    I have two C-band databases, one with a single subband, the other 
with four.  Both were taken on 3C273, but about an hour apart. 
    In comparing the wobbles in these two, I find that the amplitude 
wobbles are identical in all characteristics.  But the phase wobbles are 
not:

    In the first (single subband, at 16:44 IAT), the phase wobble (seen 
only on 27 x 28) has a notably different period than that seen in the 
second (four subbands, at 17:30 IAT).  And indeed, within the 6 minute 
duration of the first observation, the period of the phase wobble is 
seen to change.  More specifically,

    At 16:38, Period = 0.78 second (and u = 0.08)
    At 16:44, Period = 0.74 second (and u = 0.20)
    At 17:30, Period = 0.49 second (and u = 1.08). 

    The X-band data, for which the period was seen to be 0.25 seconds, 
was taken at 17:33 -- immediately following the 2nd C-band observation.  
The ratio of the wobble frequencies is about the same as that of the 
observing frequencies (8.5 GHz and 4.8 GHz)