[evlatests] C-band Switched Power Oddities

[Rick Perley]

    Ken ran an interesting test yesterday evening at C-band, the results 
of which will be reported once they are digested. 

    Here I point out four antennas whose SY values are not behaving 
correctly:

    ea05:  The PDif and PSum values, on all four IFs, give large random 
values.  This happens only rarely, but when it does, all four IFs 
misbehave at the same time.  

    ea14:  There is a resonant phenomenon in LCP only (IFs C and D), 
causing an oscillation in the measured PDif.   The amplitude of the 
oscillation can be very large -- up to a factor of two.  PSum is not 
affected. 

    ea08:  The LCP values of PDif are far too noisy.  The RCP values 
have a mean of 275 millicounts and a spread of about 10 millicounts -- 
this is normal.  The LCP values have a mean of 250, and a spread of 
about 100!  There is no pattern in the scatter.  The plot looks like 
ea06 at S-band... 

    ea19:  The RCP values of PDif have a small sinusoidal oscillation, 
with a period of about 1.5 minutes, and a peak-peak amplitude of about 
5%.  It is currently unknown if this is reflected in the visibilities -- 
I'll report on this later. 

    All other SY table values look very good.