new sbn receiver and horns  nov12

nov12

06dec12: compare calibration runs oldsbn, new sbn (before focus change), new sbn after focus change
23nov12: compare calibration runs of old,new receiver (out of focus)
14nov12: tsys contributions of new receiver chain


Intro

    A new sbn receiver was installed in the dome on 28oct12. It has:


14nov12: rcvr Tsys contributions:

    The old sbn receiver had:


    At installation the new sbn receiver had:

The 2nd postamp chassis gain was too much for the system. We changed the configuration to be:

 The Tsys contributions were computed for the new configuration of the sbnReciever

processing: x101/sbn/newrcvnov12/sbntsys.sc (sysTemp.c under svn/aosoft/src/gen/sysTemp.c).

23nov12:Compare old/new rcvr (out of focus) Calibration runs:

    Calibration runs done during oct12 with the old sbn rcvr are compared to calibration runs done with the new receiver (on 23nov12). The new receiver was 1.2 inches out of focus during these runs.
     There were  2 common sources:

Each set of StokesI  plots  contains:

Summary:

    The table below holds the values for polA and polB measured at za=10deg. If the two sources differed by a lot, then the values for  3C138 were used.


Gain
K/Jy
Tsys
degK
SEFD
Jy
Beam width
Asecs

PolA
PolB
PolA PolB PolA PolB
OldRcvr
9.5
9.5
23.4
28.0
2.5
3.0
124.0
NewRcvr
9.7
9.7
22.8
22.8
2.3
2.4
121.5

processing:101/121019/x102sbn.pro, 121123/x102sbn.pro

06dec12: compare calibration runs with new rcvr in focus.

    the new receiver was installed on 28oct12. Calibration runs were done on 23nov12 with the receiver about 1.2 inches out of focus. On 26nov12 the receiver was moved in the z direction to bring it into focus. The following sets of calibration runs were compared:

Plotting the calibration results from each run separately

The plots  below show the calibration results from each  data set.

Over plotting the 3 sets of calibration data:

The results from the 3 calibration runs are over plotted.(.ps) (.pdf):

Summary:

   

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