Modulator; Transmit - Comtec CDM-840 Installation And Operation Manual

CDM-840 Remote Router
Introduction
1.4.3

Modulator

Parameter
Operating Frequency
Frequency Reference
Scrambling
Spectral Inversion
Transmit Filtering
Transmit Filter Rolloff (Alpha)
Output Power
Power Accuracy
Transmit On/Off Ratio
Harmonics and Spurious
Output Phase Noise
Connector / Impedance
Return Loss
External Tx Carrier Off
Test Modes
1.4.3.1

Transmit

Return (Remote to Hub) Parameter
Transmit Power
Data Rate
Symbol Rate
FEC Mode
Modulation and Code Rates
Encapsulation
Specifications
950 to 2150 MHz L-Band, 100 Hz frequency resolution
±0.06 ppm (±6 x 10-8), 0 to 50°C (32 to 122°F)
Comtech, disabled
Normal or Inverted
Per IESS-308/-309 spectral mask
20%, 25%, 35%
0 to -40 dBm, in 0.1 dB steps
±1.0 dB over frequency, data rate, modulation type and temperature range of 0 to 50°C
-60 dBc minimum
Better than -60 dBc/4 kHz (typically < -65 dBc/4KHz)
Measured from Fo ±300 MHz
<1º rms double sided, 100 Hz to 1MHz (minimum of 6 dB better overall than the Intelsat
IESS-308/309 requirement)
dB/Hz
-66.0
-76.0
-86.0
-96.0
Fundamental AC line spurious is -42 dBc or lower. The sum of all other single sideband
spurious, from 0 to 0.75 x symbol rate, is -48 dBc or lower
Type 'N' female, 50Ω
20 dB, minimum
By TTL 'low' signal
CW, 1/0 pattern, 2^23-1 and 2047 patterns
Specifications
0 to -40 dBm
16 kbps to 15.35 Mbps, in 1 bps step (CCM mode) (Modulation and FEC dependent)
16 ksps – 4.5 Msps
VersaFEC Encoder (ACM and CCM modes)
• BPSK 0.488 (16.00 kbps – 2.19 Mbps)
• QPSK 0.533 (17.07 kbps – 4.80 Mbps)
• QPSK 0.631 (20.19 kbps – 5.67 Mbps)
• QPSK 0.706 (22.577 kbps – 6.34 Mbps)
• QPSK 0.803 (25.69 kbps – 7.22 Mbps)
• 8-QAM 0.642 (30.83 kbps – 8.67 Mbps)
• 8-QAM 0.711 (34.14 kbps – 9.60 Mbps)
• 8-QAM 0.780 (37.44 kbps – 10.53 Mbps)
• 16-QAM 0.731 (46.80 kbps – 13.26 Mbps)
• 16-QAM 0.780 (49.92 kbps – 14.04 Mbps)
• 16-QAM 0.829 (53.04 kbps – 14.91 Mbps)
• 16-QAM 0.853 (54.60 kbps – 15.35 Mbps)
Ultra-low overhead Streamline Encapsulation
1–11
MN-CDM840
Revision 3
Frequency
100 Hz
1 kHz
10 kHz
100 kHz