Comtech EF Data SDM-300A - Manual (Page 382)

SDM-300A Satellite Modem Revision 6
Specifications MN/SDM300A.IOM
19–26
19.8.2.6 Doppler Tracking Performance
The modem tracks the Doppler shown below with less than 0.5 dB degradation for symbol
rates
≥ 64 ksym/s. The performance applies only to the QPSK rates of 1/2, 3/4, and 7/8 with
Viterbi decoding or Viterbi with Reed-Solomon decoding.
Doppler Offset 15 Hz
Doppler Rate 20 Hz/sec
Doppler Acquisition 35 Hz/sec 2
19.8.2.7 Receive Clock Switching Due to Failure of Selected Clock
The modem will automatically switch the RX clock source to RX satellite on failure of the
selected clock.
19.8.2.8 Receive Clock Phase Adjustment
The operator can set the RX clock phase to Normal or Inverted.
19.8.2.9 Receive Clock Jitter
The RX clock will have less than 2% jitter.
19.8.2.10 Receive Data Phase Adjustment
The operator can set the RX data phase to Normal or Inverted.
19.8.2.11 Receive Data Stable Condition
Received data will be held stable (all 1’s) at the output of the modem for the fault conditions
listed in the Fault tree, then set RX AIS.