Transmission A New Correlator Table 2.4 shows the capacity of the current VLA correlator, whose properties were specified in the mid-1970's. This correlator is described in more detail elsewhere, and we discuss here only how it would appear to the observer. Each of the four baseband pairs can operate independently, giving a great deal of flexibility.
More complicated modes are also possible, since each baseband pair is independent.
Finally, this correlator design can handle up to four independently-tunable IF pairs if these are provided by the LO system. Even with only two independent LO systems, one could observe simultaneously two lines, or a narrow line and a broad-band continuum. The MMA correlator requirements do differ from those of the in several respects, however. Deep continuum imaging experiments would use a total bandwidth of 16 GHz, as in the MMA, apportioned as two polarizations of 8 GHz each. As 500 MHz is the widest required individual bandwidth, sixteen separate input pairs of this width or eight pairs of 1 GHz would be appropriate for the correlator.