Comtech EF Data CDM-425, Installation And Operation Manual

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CDM-425 Advanced Satellite Modem
Revision 0
Front Panel Operation 6–24 MN-CDM-425
Use the
▲▼ arrow keys to edit the setting in 10 kHz increments. Press
ENTER .
Spectrum Invert – Use the
▲▼ arrow keys to set
Spectrum Invert as Off or On . Press ENTER .
SPECTRUM INVERT should normally be in the OFF position. Rx spectrum is
inverted in the ON position (which is the same as reversing the direction of
phase rotation in the demodulator). When in BPSK mode, note that the
demodulator automatically synchronizes to either the normal time-ordering
of bits FEC codeword pairs, or the inverted ordering used by certain other
manufacturers.
Rx
α (Rx Alpha Filter Rolloff Factor)
– Use the
▲▼ arrow keys to select the
Tx
α
. Press
ENTER . Valid settings are:
Rxα (Rx Alpha Rollout Factor) (%) Default
0.12 0.35
Select Rxα = 0.35 if the Txα of the signal being received is 0.25 or 0.35.
Select Rxα = 0.12 if the Txα of the signal being received is 0.20, 0.15, 0.10, or
0.05.