Operating instructions

DMD20/DMD20 LBST Universal Satellite Modem User Interfaces
TM103 – Rev. 2.8 4-7
LBST: Spectral inversion may be required if the BUC LO
is higher in frequency than the BUC output frequency.
When BUC LO is higher than the BUC output frequency,
this creates a spectral inversion and the IF Spectrum
must be again inverted to compensate.
MODULATION {QPSK, BPSK, OQPSK, 8PSK, 16QAM}
Allows the user to select the modulation type.
SPECTRAL MASK {Intelsat 0.35, DVB SAT 0.35, DVB SAT 0.25, DVB
SAT 0.20}
Allows the user to set the spectral shape of Tx Data
Filter.
COMPENSATION {0.0 – 1.0}
Allows you to offset output power by up to 1 dbm. This
is intended as a correction for user cabinet connectors.
DATA (menu)
DATA RATE (bps) {Refer to Technical Specs for Data Rates}
Allows the user to set the Data Rate in bps steps via the
Front Panel Arrows or Keypad.
SYMB RATE (sps) Allows the user to view the Symbol Rate.
INNER FEC Viterbi {1/2, 3/4, 7/8, None}
Optional FEC Rates:
Sequential {1/2, 3/4, 7/8}
Trellis 8PSK {2/3}
Turbo ≤ 5 Mbps {.793, .495}
Turbo ≤ 20Mbps {1/2, 3/4, 7/8}
Comstream Seq {3/4}
DVB VIT {1/2, 2/3, 3/4, 5/6, 7/8}
DVB Trellis {2/3, 5/6, 8/9}
Allows the user to select the Tx Code Rate and Type
TPC INTERLEAVER {DISABLE, ENABLE}
Allows user to disable or enable the TPC Interleaver.
Valid only for Radyne turbo codes TPC.495 and
TPC.793
DIFF CODING {ENABLED, DISABLE}
Allows the user to enable or disable the Differential
Encoder. Having the encoder enabled ensures proper
phase lock. May not be adjustable in some modes.
SCRAMBLER SEL {NONE, V.35-IESS, V.35 CITT, V.35 EF, IBS
w/Optional Framing and optional Reed-Solomon,
Reed-Solomon Scrambler w/Optional Framing,
CCITT, V.35FC, OM-73, V.35EF_RS, TPC
SCRAMBLER (Turbo Codec), DVB, EDMAC}
Allows the user to select the descrambler type.