Table of Contents
Advertisement
SDM-309B Satellite Modem
The modem consists of the following assemblies:
Chassis with Power Supply
PCB, Monitor and Control
PCB, Modulator
PCB, Demodulator
PCB, Viterbi Decoder
PCB, Front Panel Control Board
PCB, Mother Board
PCB, Internal Channel Unit
(External Channel Unit)
PCB, Mod Daughter Variable Rate
PCB, Mod Daughter Fixed Rate
PCB, Demod Daughter Variable Rate
PCB, Demod Daughter Fixed Rate
Note: X= various options available on the modulator and demodulator boards. Refer to
Table 6-3 for more information on the options available for each board.
*Older versions of the Viterbi Decoder board can also be used in the SDM-309B
modem. Refer to Chapter 5, Section 5.2 for more information on the available revisions
and compatibility information.
1.4 System Specification
Table 1-1 lists the operating specifications of the modem. The bit energy-to-noise ratio
(Eb/N0) required to achieve 10-5 and 10-7 bit error rates is listed in Table 1-2. The
typical bit error rate performance of the modem is shown in Figure 1-5, and a typical
output spectrum of the modem is shown in Figure 1-6.
Operating Frequency Range
Type of Modulation
Operating Channel Spacing
Bit Error Rate
Digital Interface
Digital Data Rate
MN/U-SDM309B Rev. #
Assembly
(IBS)
(D&I)
Table 1-1 SDM-309B Satellite Modem Specification
IBS/M1200P
D&I/M1200P
External Channel Unit
(See Appendix C)
Drawing No.
AS/1100-3
AS/0356
AS/0773-X
AS/0778-X
AS/2133*
AS/0361
AS/0979-1
AS/1010 &
AS/1011 or
AS/1455
See Appendix C
AS/0930-2 or
AS/0715
AS/0929-2 or
AS/0698
System Specifications
50 to 90 MHz, or 100 to 180 Mhz
Synthesized in 2.5 KHz Steps
Quadrature Phase Shift Keying
Less Than .5 dB degradation operating with
2 adjacent like channels each 10 dB higher
at 1.3 times the symbol rate or 75 KHz
minimum
See Table 1-2
V.35, RS/422, & G.703
G.703 - T1 & E1
RS422/449, DS1, V.35, G.703
64 to 2048 Kb/s Configurable Choice
of up to Four pre-defined fixed Rates
or Variable Rate Option
Introduction
1-1–7
Advertisement
Table of Contents
