Specifications

SDM-300Ls Satellite Modem Revision 0
Burst Mode Modulator Operation Addendum A
B–5
B.2.12 Modulated IF Output Shape
The modem meets the following transmit output spectral mask specifications. The desired
mask is selectable from the front panel or remotely.
• INTELSAT/EUTELSAT
• Closed net (Comtech EF Data)
B.2.13 Spurious Emissions
Spurious emissions are measured relative to the power of the modulated carrier. The
measurement is done with the carrier on in continuous mode and modulated by the
correct data/clock signal. Spurious emissions measured in a 3 kHz bandwidth at the
transmit IF output are:
0 to 500 MHz (-5 to -30 dBm) -55 dBc
0 to 500 MHz (+5 to -20 dBm > 64 kbps) -50 dBc
0 to 500 MHz (+5 to -20 dBm < 64 kbps) -45 dBc
B.2.14 Modulator Phase Error
The modulator will have less than 2° of phase error
B.2.15 Transmit IF Test Modes
The following transmit IF test modes are available to the operator. Spurious emissions in
the following test modes will be ≤ -30 dBc.
TX IF Test Modes Remarks
CW: Outputs a single carrier at the defined frequency
Offset: Dual sideband signal with lower sideband and carrier suppressed
≤ -35 dBc
Dual sideband:
Suppressed carrier ≤ -35 dBc
B.2.16 Modulator Spectrum Rotation
The operator can select Normal or Inverted spectrum of the Modulator Output.