Comtech EF Data DMD1050TS - Page 153

DMD1050TS Satellite Modem Board
Revision 1
Web Browser 7–31 MN-DMD1050TS
Receive | General | IF Page
Frequency (MHz) • 950 – 2050 MHz Use to enter the Modulator Frequency in 1 Hz increments.
Spectrum • NORMAL
• INVERTED
Use to invert the direction of rotation for PSK modulation.
Normal meets the IESS Specification.
Modulation
•
BPSK
• QPSK
• OQPSK
• 8PSK
• 16QAM
• 8QAM
• 16APSK
Use to select the demodulation type.
Spectral Mask
•
DVBSAT .20 (optional)
• DVBSAT .25 (optional)
• DVBSAT .35 (optional)
• DVB 0.35
• DVB 0.25
• INTELSAT .35
• MIL 188 165A
Use to set the spectral shape of Tx Data Filter.
Sweep Range
(+/- KHz)
• ±0 to 255 kHz Use to set the acquisition range for the demodulator.
Sweep Delay (sec)
•
0.0 – 900.0 sec
• 0.00 – 6500.0 sec
Use to set the reacquisition delay time in 1/10
th
second
increments.
Reacquisition Range
(+/- Hz)
• 0 – 32000 Hz
• 0 – 65500 Hz
Use to set the reacquisition sweep in 1 Hz increments.
Adj Carrier Power
•
NORMAL
• SUPRESSED
Use to set the adjacent carrier as Normal or Suppressed
(High Power). The unit will increase or decrease post
dissemination gain as necessary.
Fast Acquisition
•
DISABLED
• ENABLED
Disable or enable the Rx Fast Acquisition capability for low
symbol rates.
Carrier Input Level
Limit
• -30 to -90 dBm (should
this be 90 or -90?)
Use to set the minimum carrier receive level when a carrier
drops below this level. The modem will sweep and try to
acquire a new signal. This prevents extremely small carriers
from falsely locking the modem.
Adjust the low-level threshold limit for input power. You can
specify a minimum operational signal level at which the
system can operate. This allows you to have some control
in tuning a real signal, as opposed to an adjacent bleed
through, or some other rogue signal.
An Input power level below the threshold limit causes a
major Input Level alarm on the demodulator. However, this
could be problematic to a software algorithm for auto-assist
antenna acquisition. The problem could occur if the
algorithm uses signal lock as a parameter for antenna
signal acquisition that is not specifically qualified with the
Input Level indicator. This is most applicable to the
DMD1050 and DMD1050TS card based modems.
Eb/No Alarm Thrsh
•
0.0 to 9.9 dB
Use to select an Eb/No level that will trigger an alarm when
the received Eb/No is worse.