
User Interfaces DMDVB20 LBST Satellite Modem
4-6 TM138 – Rev. 1.0
The UPLINK FREQUENCY is a calculated measurement
of both the BUC LO and OSC SIDE BAND. Once the
menus are entered correctly, the user can control the
uplink Frequency from this menu.
POWER (dBm) {0 to -25 dBm}
Allows the user to enter the Transmitter Power Level.
CARRIER {ON, OFF, AUTO, VSAT, RTS}
Allows the user to select the carrier type. Refer to
Appendix C for further information.
CARR DLY(SEC) {0-255}
Allows the user to select the time delay after power-up
before the Tx Carrier may be enabled. This allows time
for the BUC to stabilize.
SPECTRUM {NORMAL, INVERTED}
Allows the user to invert the direction of rotation for
QPSK Modulation. Normal meets the IESS
Specification.
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 {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}
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