C-Band receiver

The C-band receiver has one beam, with dual polarizations. The feed has a cooled OMT producing linear polarizations. You can select circular polarization synthesized using a hybrid (after the first amplifiers) in the front-end. The allowed internal switching mode is frequency switching. The full instantaneous bandwidth is currently 3.8 GHz.

There is choice between two noise diodes with different levels (~10% or ~100% of the system temperature) for flux calibration.

Note

Due to the wide bandwidth of the receiver and the hybrid being after the first amplifiers, there is a large amount of cross-talk between the LCP and RCP channels when circular polarization is used. The stability of the amplifiers control the time over which the cross-talk between LCP and RCP will remain stable. All observations using circular polarization (mainly VLBI) will need to make calibration observations during their observing period in order to correct for the cross-talk.