Ch 430 Mhz calibration

mar 2005

There is a 430 Mhz receiver system on the carriage house line feed. It can be used for transmitting and receiving. It has native circular polarization. Other 430 systems include the dome 430 and the 430 yagi (mounted on the carriage house).

Sections:

History
Recent system performance measurements
Daily monitoring of Tsys
calibration measurements
miscellaneous
cal values

History:

jan05: last week crr2/lrr2 10 Mhz IF filter replaced with 20 Mhz IF FILTER

27sep05: updated cal values.

30dec04: filters now in front of both pols to get rid of tv station intermods.

oct04: filter placed in front of dome polA dewar removes tv station intermods.

Calibration measurements:

mar05: GAIN CURVE.

Miscellaneous:

mar05 GAIN CURVE.

Calibration data taken mar05 was used to compute a gain curve at 430 Mhz. The gain curve was a function of za only : g(za)= c0 + c1*za + c2*(za-14)^2 + c3*(za-14)^3 . The last two terms (za-14) are only used for za gt than 14 degrees. The plots show the data and the gain curve fits (.ps) (.pdf) :

fig 1: This is the az/za coverage for the gain curves.
Fig2: The gain, tsys, sefd, and average beam widths for the data used to make the gain curves. The data was taken in mar05. Most of this data was used to make a pointing model for the 430ch receiver.
Fig 3: Top the data and fits. Bottom the fit residuals. The fit residuals are .57 Jy. The source B1843+098 looks like it's flux is a bit high at 430Mhz.

This gain curve is now installed in the ao idl installation. There is also a description of the gain curves and how to access them.

processing: x101/430ch/mar05/dogainfit.pro

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