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).


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


  • Note sure about the date: strongest digital tv stations no longer falling in cavity filter notches. 
  • Probably getting intermods with cavity filter.
  • PolA: removed cavity filter, put bandpass filter (that was after lna) before the dewar to cut down on the intermods.
  • 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.


    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) :     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/