Comtech EF Data SDM-300L3 - Manual (Page 327)

SDM-300L3 Satellite Modem Revision 0
Specifications MN/SDM300L3.IOM
14–21
14.7.16 Receive Input Power (Desired Carrier)
The modem can meet the specified BER and automatically adjust to a receive input power.
The minimum input signal level is –135 dBm + 10 log (Symbol Rate). E.g. (-98 dBm @
4.8 Ks/s). The maximum desired input signal level is –85 dBm + 10 log (symbol rate).
Monitor accuracy is
± 7.5 dB. See Figure 14-2.
Figure 14-2. Carrier Level vs Symbol Rate
14.7.17 Demodulator Channel Spacing/Adjacent Carrier Performance
The modem BER will be degraded less than 0.5 dB with the following receive signal:
• Two like-modulated carriers spaced 1.3 times the symbol rate from the receive
frequency, and/or 1.2 times the acquisition range, whichever is larger.
• Each adjacent carrier up to 10 dBc higher in power than the desired carrier.
• A single adjacent carrier spaced 1.4 times the symbol rate, up to +20 dBc.
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
1 10 100 1000 10000
Symbol Rate (Ksym/s)
Carrier Level (dBm)
Maximum Level
Minimum Level
Carrier Level (vs) Symbol Rate
300L_levels.xls