sband high (3-4 Ghz receiver)

mar02

     The sband high (sbh) receiver covers 3 to 4 Ghz. It has  a quadridge OMT (native linear polarization) and a ying/kildal horn. The receiver was installed on the telescope 22mar02.

history
Recent system performance measurements
Daily monitoring of Tsys.
Dewar temperatures
Calibration measurements
Miscellaneous
cal values


History:

09mar04: Measured cal values (new diodes installed 13feb04) using sky and absorber
13feb04: shi receiver moved down .8 inches into focus, new cal diodes installed.
09may03: measured cal values using sky and absorber.
22mar02: receiver installed on telescope


Calibration measurements:

recent system performance measurements
17jun11: sbh calibration used to measure 1az term of platform.
02jul09: Tsys vs freq and cal values over entire band.
Feb04-Jun04: sbh GAIN CURVES.
Feb04-Jun04: System performance of data used for gain curves.
may03-sep03: sbh GAIN CURVES.
may03-sep03: System performance of data used for gain curves.
08apr02,11apr02 calibration runs.  Performance: gain,tsys,sefd,pnterr,etc..
23mar02: cal and Tsys versus frequency.


Miscellaneous:

09may03: resonances in the sbh receiver.

All measurements by date:



Feb04 to Jun04  fit GAIN CURVES to calib data.  (top...)

link to gain curve plot

    Gain curves were fit to the sband high  calibration gain data using  13Feb04  through 30jun04.  The start of this epoch was after the als were replaced and the dewar was lower .8 inches to bring it into focus. The plots show the gain data (black) and the fits (red) for 3300, 3500, 3700, and 3825 Mhz. These gain equations were installed on 03Jul04 and back data to be valid starting on 13feb04.

    The routine gainget() or corhgainget() will now return the sbh gain for data after 12feb04 from these
equations. The coefficients can be found in the ascii file  data/gain.datR8 (this is provided in the AO idl
distribution for correlator routines). You can also find a copy of it at AO in /pkg/rsi/local/libao/phil/data/gain.datR8.
processing: x101/sbh/mar04/dogainfit.pro


feb04 thru jun04 : System performance of data used to compute gain curves.  (top...)


     Heiles calibration scans done from 13feb04 (new cals, horn lowered) thru 30jun04 were used to measure the
system performance. This data was then used to compute the gain curves used after 12feb04.

    The first set of plots show the system performance with all frequencies overplotted. The sources are identified
by symbol and the frequencies by color.

The second set of plots has the data plotted separately for each frequency. The colors and symbols are used to differentiate the sources. The figures are: processing: x101/sbh/mar04/doit.pro


May03 to Sep03  fit GAIN CURVES to calib data.  (top...)

link to gain curve plot

    Gain curves were fit to the sband high  gain data from 15may03 through 30sep03.  The start of this epoch was after the shimmin g of the elevation rails in feb03. The end date was chosen so that the cal had not drifted too much (see warning below). The plots show the gain data (black) and the fits (red) for 3300, 3500, 3700, and 3900 Mhz. These gain equations were installed on 10mar04.


Warning: The sbh cal was drifting in time (see tsys plots). During this period it was relatively stable. Use these curves outside this region with care. The cals were replaced in feb04.

    The routine gainget() or corhgainget() will now return the sbh gain for data after 01mar03 from these
equations. The coefficients can be found in the ascii file  data/gain.datR8 (this is provided in the AO idl
distribution for correlator routines). You can also find a copy of it at AO in /home/phil/idl/data/gain.datR8.

processing: x101/sbh/mar03/dogainfit.pro


may03 thru feb04 : System performance of data used to compute gain curves.  (top...)


     Heiles calibration scans done from 15may03 (after shimming) thru 30sep03 were used to measure the
system performance. This data was then used to compute the gain curves used after 01mar03.

    The first set of plots show the system performance with all frequencies overplotted. The sources are identified
by symbol and the frequencies by color.

The second set of plots has the data plotted separately for each frequency. The colors and symbols are used to differentiate the sources. The figures are:
processing: x101/sbh/mar03/doit.pro


08apr02,11apr02: calibration runs.  (top...)

    Calibration runs were done on 08apr02 (B0038+328,B0316+162:CTA21,B0518+165:3C138) during the day and on 11apr02 (B1328+254,B1535+139) using the standard heiles calibration scans.  Data was taken at 3300, 3500, 3700, and 3900 Mhz (Note: the cal values at 3900 Mhz were extrapolated from measured cal values at 3700 Mhz). The plots show the system performance.
processing: x101/sbh/apr02/doit.pro


23mar02: cal and tsys versus frequency. (top...)

    While tracking blank sky, 5 second cal on/offs were done across the frequency range 3 Ghz to 3.7 Ghz using the high correlated cal. 3.7 to 4 Ghz was not covered because we do not yet have cal values for this range. When the cals were measured on the hill with the horn pointing at the sky, the 3.7 to 4 Ghz range was contaminated by the satellite tv band (looking straight up, the beam is +/- 60 degrees ). On the telescope the narrow beam limits how often we see a satellite.
The plots show cal value versus frequency and the system temperature versus frequency. It looks a bit strange that the shape of the high and low cal differ by so much for some of the cals (since they differ by a 10db coupler).
processing: x101/020322/doitcals.pro


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