[evlatests] More on wobbles and wiggles

[Rick Perley]

    SPFLG is a very useful program for detecting curious phenomena in 
time and frequency.  A more careful perusal of all the 66 (calibrated) 
baselines reveals the following:

    1) The time/frequency oscillations reported in my last email are 
seen on many other baselines, all of them involving antenna 5 (located 
at W8).  On all these, the frequency scale is much finer than on 5 x 
15.   There are three baselines involving this antenna which do not seem 
to show this effect:  5 x 2, 5 x 8, and 5 x 28. 

    2) The 'standard' wobbles are easily seen on the usual baselines:  
15 x 19, 19 x 25, 2 x 15, and 2 x 19.  The SPFLG display shows that 
these wobbles vary only in time -- there is no frequency structure 
(i.e., they are the same in all channels in all subbands).   We can also 
see that for baseline 19 x 25, the wobble frequency in two times higher 
in phase than it is in amplitude! 

    All other baselines are fabulously stable, with no oddities worthy 
of mention. 

    3) I have reported earlier on the appearance of an RFI spike on some 
antennas at 1408 MHz.  Some other baselines show an RFI spike at 1466.75 
MHz.