[evlatests] 10-second no-fringe problem

[Rick Perley]

     Ken wondered if the problem noted yesterday occurred at any other 
band.

     The answer appears to be 'no'.    I've checked P, L, S, C and Ku 
bands.  All clean.

     However, appearances can be deceiving:    Every non-X-band 
observation in my script requires a change in frequency from some other 
band.  This requires a subreflector rotation, plus correlator 
reconfiguration, which in most cases takes up more than 10 seconds. 
Hence, I don't think it's actually possible to judge whether this 
'mis-tuning' issue occurs other than at X-band  -- the only band where 
there is no subreflector motion, as it is taken following X-band 
referenced pointing.

     The possible exception will be changes between Q and Ka -- rotation 
is very small for this pair.    A review of the data shows no evidence 
of the initial 10-second no-fringe problem.

     Rick