PolA ripple 430 dome
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:
The plots show the results of the
position switching (.ps) (.pdf):
- radar, radioastronomy switch on polA bypassed with a cable.
- on/off position switching on blank sky with 60 seconds on, then
- mock spectrometer with 16 Mhz bw used to take the data.
- 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.
- The polA ripple in 430 dome is not being caused by the