BBSYN is used to set the frequency for the BBC assigned to each baseband channel. This number will be overridden if FREQ or DOPPLER is specified in the SCHED keyin file. Even if DOPPLER is specified, this value serves as the default for continuum sources for which no velocity or DOPSRC is specified. All baseband channels assigned to the same BBC should be assigned the same frequency. If not, the last will probably be used and the monitor system will get confused about what signals are present. Please see FREQREF for a discussion of required parameters.
For MkIV all BBCs at a given station should fall in the range 100 - 220 (the ``Low patch'') or 220 - 500 the ``High patch'').