[evlatests] EVLA and VLA sensitivities, 1700 to 1900 MHz

[Rick Perley]

    I have calibrated the 'AIPS Weights' for the VLA's extended range 
sensitivity, from 1700 to 1900 MHz. 

    Two antennas, 5 and 10, have had their filters removed, allowing 
them to tune to 1900 MHz. 

    Both perform very well in the new range.  For both, the antenna 
sensitivity declines, more or less steadily from the their nominal 
values at 1720 MHz to the upper range.  The G/Tsys loss (sq. rt. of AIPS 
wt.) drops by about 40% for both antennas.  By comparison, the best EVLA 
antennas (14, 16 and 23) are essentially unchanged in sensitivity over 
the range, with values about equal to the best VLA antennas at 1700 MHz. 
    EVLA antenna 13 is very poor at high frequencies -- undoubtedly a 
result of its extremely sloped bandpass.  Antennas 17, 18, and 26 are 
middling. 

    The results above for the VLA are as expected.