CARMA

• 8 antennas are phased together in a set of beamformers and recorded on one Mk6 recorder. 
• a separate 'reference' antenna is connected to a standard BDC and R2DBE and is recorded on a separate Mk6 recorder.

LO1 = 3 * (7 * (9 * fsynth - 10 MHz) + 50 MHz)
    = 221099.999970 MHz for fsynth = 1170.158730 Hz

A diagram of the CARMA IF system is shown below.  The signals for the reference antenna are taken from wideband directional couplers in the fiber IF receiver boxes; these 1-9 GHz bands are sent to standard EHT block downconvertes and R2DBEs.  The signals for the beamformers are taken from the outputs of the CARMA analog downconverters.