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System operation, Chapter 3. system operation – Comtech EF Data MBT-4000B User Manual

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3-1

Chapter 3. System Operation

3.1 D

ESCRIPTION

The MBT 4000B supports LNBs for receive down conversion. It outputs +17VDC
nominal and 10 MHz on the “L-Band input” connector. The LNB amplifies the input RF
signal and down converts it to L-Band in the range of 950 to 1750 MHz (there may be
instances that the L-Band range = 950 to 1450 MHz ). The choice of which downlink
frequency band is determined by the selection of a frequency range, usually from one of
LNBs in the following bands:

For C-Band

For Ku-Band

3.625 to 4.2 GHz
4.50 to 4.80 GHz

10.95 to 11.70 GHz
11.70 to 12.20 GHz
12.25 to 12.75 GHz


IMPORTANT

LNBs are available that are either externally referenced (EXT REF) or internally
referenced (INT REF). DC power is supplied to the LNB through the IFL cable from
the MBT 4000B for both types.


The standard LNB noise temperature is:

For C-Band < 35

°K.

For Ku- Band < 65

°K.