### Setup of the Receivers (Frontends)

At the prompt PAKO > enter, e.g.:

    RECEIVER A100                               ! defaults for all parameters
    RECEIVER B100 12CO(1-0)                     ! using line catalog
    RECEIVER A230 12CO(2-1) 230.537990 LSB      ! basic parameters explicit

Normally we use the RECEIVER command with 2 parameters: a receiver name and a line name. The line name must be the name of a line in the line catalog selected earlier.

Alternatively the frequency and sideband can be specified directly as the 3rd an 4th parameter.

One RECEIVER command is need for each receiver.

After all receivers are set up, and a source has been selected, the telescope operator or receiver engineer will tune the receivers. After tuning, he can tell you for each receiver: the ambient and cold load temperatures needed for the calibration, as well as the image band gain ratio.

These values describe physical parameters of the system that are not directly controlled, but which are important for the calibration of the data during data processing.

You can set these values with options of RECEIVER.

    RECEIVER B100 12CO(1-0) 115.271204 LSB -    ! all parameters explicit
                  /doppler fixed           -    ! fixed: no Doppler correction
                  /gain 0.002              -    ! image sideband gain
                  /tempLoad 88 277         -    ! cold and ambient load temperatures
                  /efficiency 0.96 0.77    -    ! forward and (main) beam efficiencies
                  /scale beam                   ! scale (main) beam brightness temperature
    RECEIVER B230 /gain -22 db                  ! image sideband gain in [dB]

Note that with the syntax /GAIN -22 db you can specify the image gain directly in [dB].

Option /EFFICIENCY allows to specify values for the forward and (main) beam efficiencies.

Normally the system will provide reasonable defaults for all these calibation parameters.

Option /SCALE allows to choose the calibration scale: ANTENNA temperature or (main) BEAM brightness temperature.