[evlatests] X-band yesterday

[Rick Perley]

    All 27 antennas worked very well. 

    But a remarkable 'feature' in the TY table was discovered:

    The X-band observations were set up in a special way, to avoid a 
known 'feature':  It seems that the scan which *precedes* a reference 
pointing scan will always fail to give any data.  Ken says this is a 
known problem, which will be repaired soon. 

    In my 'stress test', I run a 'reference pointing' at X-band.  To 
avoid wiping out the preceding C-band observation, a 'dummy' X-band 
observation was inserted between the C-band and the X-band reference 
pointing.  This 'dummy' scan requested 10 second integration.  The 
reference pointing also used 10 second integrations, while the real 
X-band on-source observation (which followed the referenced pointing) 
used 0.416 second averaging.

    The visibility data were exactly as expected.  However, when I went 
to review the Tsys data (in the TY table), I found to my amazement that 
the data were logged only once every 10 seconds (which is the interval 
set by the preceding two scans, at this band). 

    Looking ahead (U-band), all rates, in both visibility and monitors, 
were at the requested 0.416 second rate. 

    Why were the Tsys data only logged once per 10 seconds?