General Dynamics CG-1220, Operation And Maintenance Manual

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Theory
2-2 CG-1220 DTR
2.2 Optional Configurations
2.2.1 Dual Polarization Input
Versatile unit configurations allow dual-receive signal polarization to be connected
to separate RF inputs on the DTR’s back panel. Linear polarizations (vertical and
horizontal) and circular polarizations (clockwise and counter clockwise) can be
connected to the DTR without external combining or switching.
2.2.2 Down Converter Frequencies
RF signals enter the DTR on one of six possible inputs and are routed to the proper
Block Down Converter (BDC) for conversion to an L-band signal of 950 MHz to
2050 MHz. Each band accepts an input level of –110 to –40 dBm (decibel
referred to 1 milliwatt).
The output of each block downconverter is connected to appropriate switching and
routed to the input of the L-band downconverter. To prevent unnecessary heat and
noise, the DC power to each BDC is switched so that the BDC is only powered
when its particular band is selected.