cband wide (4 to 8 ghz)

aug17

     The cband wide receiver covers 4 to 8 GHz. It has a linear omt followed by hybrids (in the dewar) to convert to circular polarization. The cal values are injected after the hybrid and before the first lna.
    The receiver was installed in jul17.
    The wide (4GHz) bandwidth needs the 10Ghz upconverted mixer to be able to cover the entire band  (the 1 GHz if1 bandwidth would require the LO inside the rf band if the 2-12 GHz mixer was used to cover the entire band).


Sections:

History
Recent system performance measurements
Daily monitoring of Tsys
Dewar temperatures
Calibration measurements
commisioning
All measurements in date order


History:



Calibration measurements:


All measurements in date order

170809: manually track sources to get initial pointing offsets.
170810: initial power levels measured with upstairs if1 power meter.
170810: cal values measured on hilltop 27apr17. (includes flange temperature)
170811: calibration scans at original horn position
170814: moved horn uphill .391 inches (wrong direction, got my sign wrong :) )
170815: moved horn downhill from original position .628 inches, then more calibration scans.



170810: Initial measurement of the if1 power levels.

    The cbw power levels were measured using the if1 power meter (upstairs before the fiber optic transmitter).  For the 1 Ghz bandwidth, the optimal value measured on the power meter should be -33 dbm (the meter has a 20db pad in front of it).
The setup was:

The plots show the measured IF1 power vs frequency (.ps) (.pdf):

Summary:

procesing: x101/170810/cbwtest.pro



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