Comtech EF Data SDM-300A - Manual (Page 366)

SDM-300A Satellite Modem Revision 6
Specifications MN/SDM300A.IOM
19–10
19.4.11 Transmit IF Output Switch
When set to Off, no signal present at the output is greater than –60 dBm, measured in a
3 kHz bandwidth from 0 to 500 MHz.
19.4.12 Transmit IF Power
The TX IF power is operator selectable from –5 to –30 dBm, in 0.1 dB steps, with an
accuracy of
± 0.5 dB. The maximum drift due to temperature change over the specified
range is ± 0.5 dB.
As an option the output can be selectable from +5 to –20 dBm, in 0.1 dB steps, with an
accuracy of
± 0.5 dB. The maximum drift due to temperature change over the specified
range is ± 0.5 dB.
19.4.13 Modulator Power Offset
An offset to the displayed IF output power may be entered from –99.0 to +99.0 dB, in 0.1 dB
steps.
19.4.14 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 and Comstream)
• Closed net (Fairchild compatible)
• Closed net (SDM-51, SDM-52)
19.4.15 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
19.4.16 Modulator Phase Error
The modulator has less than 2 ° of phase error