[evlatests] L-Band Pointing

[Rick Perley]

    I neglected to report one other curious result from the holography 
tests. 

    The scanning gives us useful information on antenna pointing -- but 
only in the elevation axis, as this was the direction of the scan.

    All EVLA antennas, except 17, point perfectly at L-band (perfectly 
defined as seeing the amplitudes on opposite sides of the half-power 
raster scan be of amplitude within a few percent). 
    Antenna 17 is severely mispointed -- by about 3 arcminutes in 
elevation (unknown in azimuth). 
    Most *VLA* antennas show a significant offset in elevation pointing 
-- perhaps as large as an arcminute.  Notable ones are:  1, 2, 3, 4,  8, 
15, 19, and 28.  No VLA antenna is as good as the EVLA antennas (except 
17).  Clearly, the good behavior of the EVLA antennas is a result of the 
collimation corrections put in by Ken last week.  But why are the VLA 
antennas mispointing at L-band so badly?