SDM-300L3 Satellite Modem
Revision 0
Specifications
MN/SDM300L3.IOM
14–5
14.4 Demodulator
Specification
Summary
Table 14-3. Demodulator Specification
Receive Specifications
Input Connector
Type F Female
Input Impedance
75
Ω
Input Return Loss
≥
10 dB
Minimum Input Level, Desired Carrier
-135 dBm + 10*Log (Symbol Rate), see curve
Input Level AGC
50 dBc, see curve
Input Composite Power:
Symbol Rate
> 64 Ksym/s
<
64
Ksym/s
Absolute maximum
+30 dBc within 10 MHz of desired
+40 dBc with respect to receive signal
+50 dBc with respect to receive signal
-5 dBm
Acquisition Range
±
500 kHz, programmable in 1Hz increments.
BER Performance
(BER vs Eb/N0)
See BER performance tables
Notes: BER specified is for IF loop-back with added noise.
LNB 10 MHz Reference
On center conductor of L-band input connector, selectable
ON/OFF. Level: -3
±
3 dBm.
Source: 1. Internal High Stability Reference
2. REF EXT Supplied at 10 MHz
Performance: For phase noise, refer to L-Band Modulator 10
MHz. Frequency stability is the same as the modulator.
LNB Voltage
On center conductor of L-band input connector, selectable
ON/OFF: 13 and 18 volts per DiSEq 4.2 and 24 VDC at 500
mA, maximum
LNB Current
Programmable MIN and MAX current alarms
LNB Band Control
22kHz tone outbound from L-band connector per DiSEq 4.2.
Test Modes Pattern Monitor
Detects the presence of 2047 data pattern in RX stream and
reports BER.
Monitored Signals
Receive signal level
Raw BER
Corrected BER range 10-3 to 10-12
Eb/N0, 2.0 to 16.0 dB
Rx frequency offset –500 kHz to +500 kHz
Buffer fill status, 1 to 99% in 1% steps
