NARROW_INPUT

##
NARROW_INPUT

        [PDBI\]NARROW_INPUT Q1|Q2|Q3|Q4 Q1|Q2|Q3|Q4

        Select  the two entries of the PdBI narrow-band correlator. The PdBI re-
        ceivers have 4 GHz bandwidth (for each polarization), from IF=4  GHz  to
        IF=8  GHz.  The WIDEX correlator is able to analyse the whole bandwidth,
        but the narrow-band correlator can process only two 1 GHz wide bands.

        The receiver 4 GHz bandwidth is split into four "quarters":
                 Q1 = 4.2-5.2 GHz    Q2 = 5.0-6.0 GHz
                 Q3 = 6.0-7.0 GHz    Q4 = 6.8-7.8 GHz
        and two of them must be selected as inputs to the  narrow-band  correla-
        tor.  Any combination is possible. The polarization that is selected de-
        pends on the selected quarter:
          - the correlator input 1 can only be Q1 HOR, Q2 HOR, Q3 VER, Q4 VER
          - the correlator input 2 can only be Q1 VER, Q2 VER, Q3 HOR, Q4 HOR

        Example: NARROW_INPUT Q1 Q2 selects Q1 HOR as first input, and Q2 VER as
        second input. Simultaneous measurements of the two HOR and VER polariza-
        tions is obtained with e.g. NARROW_INPUT Q1 Q1.