[evlatests] Q-band results from tests on June 19, 2006

[Mark Claussen]

> I'll try to have something to say about Q band before the day is over.
Well I didn't quite make it.  Here are some Q-band results from Jun 19 data.


    A)  Overall. 

An 18 was broken, as Ken reported.  An 24 does not have UX converter.
There were fringes on all IFs for An 13, 14, and 16.

I saw no dropouts in amplitude or phase, but again, none were
expected.
    
    B) Returning to correct phase: 

As with the K band observations, it was difficult to tell if the
phases returned to correct values.


    C) Bandpasses. 

Antenna 14 has a spike near (but not exactly in) the center of the
6.25 MHz band in IF D.  The baseband frequency at which it appears
is about 3.5 MHz.  The spike is variable in strength but appears to 
be there much of the time.  An 13, An 16, and An 14 (ABC) seem to 
have reasonable bandpasses (as best as I can tell).

    D)  Sensitivity. 

AIPS weights were generated for all antennas and IFs. Sensitivities are
estimated based on the aips weights.

There was quite a spread in the AIPS weights for VLA/EVLA antennas.
This is likely to be due to pointing, since the reference pointing
was only done at X band (no double reference pointing).  The EVLA
antennas are not significantly worse or better than VLA antennas, but
this is a null statement.... nothing much can be said about the
sensitivities based on this data.


   E) System temperatures.   

None of the EVLA antennas had reasonable Tsys recorded in the AIPS data
(single digits).


Mark