12-30 Chapter 12
Theory of Operation
Receiver Theory
A10 Digital IF
The three 4 kHz 2nd IF signals from the sampler/mixer assemblies are input to the A10
digital IF assembly. These signals are sampled at a 16 kHz rate. A fourth input is the
analog bus, which can monitor either an external input at the rear panel AUX IN
connector, or one of 31 internal nodes. A multiplexer sequentially directs each of the
signals to the ADC (analog-to-digital converter). Here they are converted to digital form
and sent to the A9 CPU assembly for processing. Refer to “Digital Control Theory” on
page 12-9 for more information on signal processing.