Table of Contents
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CDM-740 Advanced Satellite Modem
Introduction
1.5
Summary of Specifications
1.5.1
Transmit / Modulator
Modulation
Symbol Rate Range
Data Rate Range
70/140 MHz
Operating
Frequency Range
L-Band
70/140 MHz
Frequency
Stability
L-Band
70/140 MHz
Output Power
L-Band
70/140 MHz
Power Accuracy
L-Band
Selectable
On/Off
Monitor 70/140
Tx Monitor Port
Monitor L-Band
Level
Mute
70/140 MHz
Phase Noise
L-Band
FEC
Operating Modes
Transmit Filtering
Scrambling
External Reference In/Out
Harmonics and Spurious
BUC Reference (10 MHz)
QPSK, 8-QAM and 16-QAM
4.8 ksps to 3.00 Msps, programmable in 1 sps steps
16 kbps to 9.980 Mbps, programmable in 1 bps steps
50 to 180 MHz IF, 100 Hz frequency resolution
950 to 2150 MHz L-Band, 100 Hz frequency resolution
±0.06 ppm, 0º to 50ºC (32º to 122ºF)
±0.06 ppm, 0º to 50ºC (32º to 122ºF)
-5 to -25 dBm, 0.1 dB steps
-5 to -40 dBm, 0.1 dB steps
± 1.0 dB over frequency and temperature
± 1.0 dB at 25 C over frequency and temperature
Output is L-Band.
900 MHz + IF carrier frequency
Same as L-Band frequency
-45 dBm typical
Mutes when Tx carrier is muted
< 1 degree RMS double-sided, 100 Hz to 1 MHz
< 1 degrees RMS double-sided,100 Hz to 1 MHz
Turbo Product Codec (TPC): 6 bit soft decision, proprietary
TPC:
•
Rate 21/44 QPSK
•
Rate 3/4 QPSK
•
Rate 7/8 QPSK
•
Rate 0.95 QPSK
•
Rate 3/4 8-QAM
•
Rate 7/8 8-QAM
•
Rate 0.95 8-QAM
•
Rate 3/4 16-QAM
•
Rate 7/8 16-QAM
Note: Refer to Table 5-1 for additional data rate/symbol rate information.
IESS-308/-309 spectral mask
Comtech, IESS-315 per ITU V.35 (Intelsat variant), disabled
See Sect. 1.5.3 Data Interfaces
< -60 dBc/4 kHz over operating frequency range (Typically < -65 dBc/4 kHz)
Via Tx IF center conductor, 10 MHz per reference, selectable ON/OFF, 0 dBm ±3 dB
1–10
Revision 0
MN-CDM740
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