Comtech EF Data CDM-710G, Installation And Operation Manual

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CDM-710G High-Speed Satellite Modem Revision 1
Introduction MN-CDM710G
1–15
1.5.2 Modulator
1.5.2.1 CDM-710G 70/140 MHz Modulator
Description Requirements
Frequency 52 to 88 MHz or 104 to 176 MHz in 100Hz steps. Bandwidth of transmitted
spectrum is within IF frequency range.
Impedance
75
Ω
or 50
Ω
, programmable
Connector BNC Female
Return Loss 18 dB
Output Power 0 to -20 dBm in 0.1 dB steps.
Carrier is not interrupted when changing between output power levels or
removing data connections.
Output Power Accuracy ±
0.5 dB at 25
°
C
Output Power Stability
Within
±
0.5 dB of 25C value over all specified environments
Carrier Mute 55 dB below main carrier output
Harmonics and Spurious -55 dBc/4 kHz over operating frequency range (excludes spectral mask area)
and is with a modulated carrier
-55 dBc/4 kHz 10 to 52 MHz, 176 to 250 MHz
Integrated Phase Noise Continuous component < 1 degrees RMS double-sided, 100 Hz to 10 MHz
Spectral Inversion Normal or Inverted
Quadrature Phase Error
< 2
°
Quadrature Amplitude Imbalance 0.2 dB maximum
Carrier Null
35 dB below an unmodulated carrier
Combined Amplitude Imbalance
and Quadrature Phase Error Single sideband test with suppressed sideband 35 dB minimum below
unmodulated carrier