Comtech EF Data CDM-710 Installation And Operation Manual page 84

CDM-710 Broadcast Satellite Modem
Front Panel Operation
(CONFIG: Rx) Dem
Rx Spectrum:
Automatically Detected.
This screen is 'status only' as the demodulator automatically resolves frequency inversion.
Normal or Inverted is not reported in the demodulation. Press
to the previous menu.
(CONFIG: Rx) Dem
Demod Acquisition Range:
+/-010 kHz
The value entered here determines the amount of frequency uncertainty the demodulator will
search over in order to find and lock to an incoming carrier.
To edit the demodulator acquisition search range value, use the
digit to be edited, then use the
varies from ±001 kHz to ±100 kHz. Press
(CONFIG: Rx) Dem
RX (α) Rolloff %: 20
35
The Rolloff (α) dictates how fast the spectral edges of the carrier are attenuated beyond the 3
dB bandwidth. With 20% rolloff the edge falls off more quickly than with 25% and 35%.
Select the value using the
setting is 20%; whenever the mode is changed, (α) reverts to 20% but can be modified to
25% or 35% using this menu.
(CONFIG: Rx) Dem
Rx Adaptive Equalizer:
Off On
The adaptive equalizer helps correct for linear distortion in the rest of the link. Linear distortion
includes amplitude and phase that would occur due to imperfect filtering effects, but it does not
include distortion due to non linear amplifiers.
Select operation as Off or On using the
Inv
Acq
( ▲ ▼ E)
arrow keys to change the value of that digit. The range
when done.
ENTER
α
25
( E)
arrow keys, then press
Eq
( E)
arrow keys, then press
5–20
MN/CDM710.IOM
or
ENTER CLEAR
arrow keys to select the
. The default Rolloff (α)
ENTER
.
ENTER
Revision 11
to return