[evlatests] ea22 L-band

[Rob Long]

Hello everyone,

After some pretty definitive tests today, we have determined that the 
problem with L-band setup (20 dB extra power) is related to the 
sub-reflector movement. Every time we command the SR to L-band from 
another position, the noise causes the T304's to set to the incorrect 
levels (with 20 dB of extra attenuation). When a subsequent L-band 
script is run, there is no movement of the SR and levels set correctly.

We set the antenna up for L-band and then manually moved focus and 
rotation (one at a time) and saw power levels increase by 20 dB with any 
SR movement. Once we stop movement, levels return to normal. We may need 
to work with Servo to troubleshoot the exact noise by putting couplers 
in the L-band path, using a spec an and manually moving the 
sub-reflector around.

Rob