Nyquist Filter Configuration - Comtech EF Data SDM-9000 Installation And Operation Manual

SDM-9000 Satellite Modem

3.5 Nyquist Filter Configuration

The Nyquist filter (AS/4124) is a 4.5" x 5.0" daughter card that is located on the
modulator and demodulator PCBs. The filters are capable of supporting four data/code
rate and modulation type combinations per card. There is one TX card and one RX card:
TX PCB
RX PCB
The filters include a factory programmable device that contains:
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This information is programmed into the filter PCB at calibration time. A label indicates
the symbol rates of the populated filters. For example, a Nyquist filter may be required
with four symbol rates as follows:
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Configuration information is recovered from the filter PCBs during system power-up and
initialization. The filter configuration information is available to the user. Refer to
Chapter 4 for the Configuration Modulator, Configuration Demodulator, and Utility
menus.
Rev.4
Type Part Number
AS/4124-1
AS/4124-2
Data Rates
Coding Rates
Symbol Rates
Options
21.376 MHz
22.912 MHz
29.824 MHz
34.560 MHz
Used with
Baseband Modulator PCB (AS/3969)
Baseband Demodulator PCB (AS/3970)
Configuration
3–9