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At present there are 3 types of spectral line backends (the AOS is under
repair) which can be individually
connected to any receiver.
The 1MHz filter bank, consisting of 4 units with 256 MHz each. The units
can be connected to different or the same receivers (giving bandwidths
between 256 MHz and 1024 MHz, the latter only usable with 230G2). For
example, two receivers could use 512 MHz each, or four receivers 256 MHz
each, or combinations. Each
unit can be shifted by steps of 32 MHz relative to the center frequency
of the connected receiver. If all four units are combined to 1024 MHz and
connected to 230G2, no other backend can be connected to 230G2.
- The 100kHz filter bank, consisting of 256 channels of 100 kHz
(splittable into two halves movable inside the 500 MHz instantaneous
bandwidth, and connectable to two different receivers)
- The autocorrelator: The software treats the autocorrelator
as one unit although physically it consists of two identical machines.
The following numbers are to be understood for the complete autocorrelator
Available resolutions are 10,
20, 40, 80, 320 and 1250 kHz. The bandwidth is between 20 MHz and
2 512 MHz,
depending on resolution. The correlator can be split into 8
independent subbands, each of which can be configured individually and
connected to the same or different receivers. For the larger
bandwidths (i.e. more than one subband of 80 MHz) a problem of
platforming may exist (i.e. baselines from the different subbands have
slightly different levels).