QRFH pwr Levels on telescope

Spectra at field fox  for all 3 filter configurations.
Azimuth dependence of rfi using spectra at horn output
Total power vs azimuth to check for lna compression.


    The QRFH was mounted on the 12meter and tests were done to measure the power levels using different hi pass filters. We wanted to see if a hi pass filter was needed before the lna in the cooled system. The tests were done 16 -> 21jun22.


Data taking

    Data was taken on 4 days

Plotting the FieldFox spectra during the az,el motion

   The spectral density vs  azimuth,el motion is plotted for each day.

2.8 GHz hipass filter spectra (.png)

2.5 GHz hipass filter spectra (.png)

no hipass filter spectra (.png)

Rfi from az swings with no hiPass filter (at horn output)

    The az swing spectra taken with no hi pass filter on 21jun22 were used to check the power levels and rfi vs az and el.
Each field fox spectra had the gain of the system removed so the spectral density was at the output of the QRFH.
The azimuth swings went from  6 to 81 deg elevation in 5 deg steps.

The field fox was set to:

The first set over plots the spectra from each azimuth swings and then blowups in freq (.ps) (.pdf)

dynamic spectra from the azimuth swings

    The table below shows the dynamic spectrum (spectral density vs azimuth, frequency) from each   azimuth swings

 Notes on dynamic spectra:

Rfi azimuth dependence

    The plots shows the azimuth dependence of various rfi regions seen in the data (.ps) (.pdf)

processing: x101/220622/plotspc_horn.pro

Plotting the total power vs azimuth

The total power vs azimuth was plotted to see where the lna might saturate.

Total power vs azimuth showing  power levels at input to field fox (.ps) (.pdf)

Total power vs azimuth showing  power levels at the output of the QRFH (.ps) (.pdf)


    The total power vs az,el was measured for various az,el positions and hipass filter setups.
hiPass filter
at fieldfox (dbm)
AtHornOutput (dbm)
2.8 GHz
2.5 GHz
no filter

processing: x101/220622/inpazdata.pro,plotazsw_ff.pro,plotazsw_horn.pro