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CDM-700 High Speed Satellite Modem
Front Panel Operation
If Rx Dem:
Rx Spectrum: Normal
Inverted
Select Normal or Inverted using the ◄ ► arrow keys. Press
When Normal is selected, the spectral sense of the carrier has the default transition to I and Q
constellation points.
Selecting Inverted causes the I and Q transition points to move in the opposite sense. Selecting
Inverted also can correct for spectral inversion in the uplink or downlink.
If Rx Dem:
Demod Acquisition Range:
+/- 099 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.
Edit the demodulator acquisition search range value by selecting the digit to be edited, using the
◄ ► arrow keys. The value of the digit is then changed using the ▲ ▼ arrow keys. The range
varies from ±001 kHz to ±100 kHz. Press
If Rx Demod:
RX (α) Rolloff %: 25
(
The Rolloff, or α, dictates how fast the spectral edges of the carrier are attenuated beyond the
3dB bandwidth. The default setting is 25%; with 25% rolloff, the edge falls off more quickly
than with the 35% setting.
Select the Rolloff (α) setting using the ◄ ► arrow keys. Whenever the Mode is changed, (α) reverts
to 25%, but (α) can be modified to 35% from this menu. Press
If Rx Demod:
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 Off or On using the ◄ ► arrow keys. Press
Inv is selected:
Acq is selected:
(
α
is selected:
E)
Adap-Eq is selected:
(
E)
E)
.
ENTER
35
ENTER
(
E)
.
ENTER
6–18
MN/CDM700.IOM
.
ENTER
.
Revision 5
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