PolA ripple 430 dome

aug11

Intro:

A2599 reported ripple in the 430 dome polA receiver in early aug11. It was thought that the radar,radioastronomy on polA may have been causing the problem. On 11aug11 the radar,radioastronomy switch was bypassed and a test was done.
The setup was:

radar, radioastronomy switch on polA bypassed with a cable.
on/off position switching on blank sky with 60 seconds on, then off.
mock spectrometer with 16 Mhz bw used to take the data.

The plots show the results of the position switching (.ps) (.pdf):

top: 60 second off source average bandpass. red polA, green polB

PolA bandpass has lots of ripple

bottom: on/off-1 for 60 sec averages.

PolB (green) is offset for display purposes.
The ripples in the polA bandpass don't cancel.

SUMMARY:

The polA ripple in 430 dome is not being caused by the radar,radioastronmy switch.

processing: 110811/test430.pro