Comtech EF Data SDM-650B - Manual (Page 167)

Rev. 6 A–1
Appendix A.
DATA RATES AND FILTERS
The modem will operate at data rates from 19.2 kbit/s to 3.584 Mbit/s. Data rates from
19.2 to 48 kbit/s are 1/2 rate BPSK only.
Variable rate filters can operate from 19.2 to 2048 kbit/s. Fixed rate filters allow
operation from 19.2 to 3584 kbit/s.
This appendix covers:
• Data rate change instructions for fixed rate and variable rate filters
• Differences between a fixed rate filter and a variable rate filter
• Modem configuration for each filter type
A.1 Fixed Rate Filters
A.1.1 Data Rate Change Instructions
1. Turn OFF modem power switch.
2. Remove the modulator card (AS/0773) by using the black card ejectors.
3. Remove the two screws securing the daughter card (AS/0715) with a Phillips
screwdriver. See Figure A-1 for location of the hardware.
4. Remove the daughter card from the modulator.