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Figure 5-7. baseband loopback block diagram – Comtech EF Data SDM-9000 User Manual

Page 154

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Theory of Operation

SDM-9000 Satellite Modem

5–26

Rev. 4

5.5.3.3 Loopbacks

5.5.3.3.1 Baseband Loopback

Baseband loopback provides loopback at the terrestrial interface. The near end
equipment loops back through the baseband loopback relays. The far end equipment
loops through the demodulator, interface, and modulator. Refer to Figure 5-7 for a block
diagram.

BASEBAND

TX DATA/CLOCK

TERRESTRIAL

RX DATA/CLOCK

TX DATA

RX DATA

MODULATOR

DATA

DEMODULATOR

DATA

MODULATOR

MODULE

DEMODULATOR

MODULE

INTERFACE

MODULE

TX IF OUT

RX IF IN

DATA/CLOCK

LOOPBACK

RELAYS

Figure 5-7. Baseband Loopback Block Diagram