Comtech EF Data CDD-880, Installation And Operation Manual

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CDD-880 Multi Receiver Router MN-CDD880
Ethernet-based Remote Product Management Revision 2
6–21
Global Demodulator Settings
This Demodulator Frequency Calculator conveniently allows you to eliminate the guesswork
associated between the demodulator’s L-Band Frequency and the terminal’s RF frequency. If the
LNB LO Mix and LNB LO Frequency and either of the frequencies are known, then the other can
be calculated. Use this calculator to start from either the Rx RF Frequency or Rx L-Band
Frequency and calculate the “other” frequency.
The CDD-880 supports a contiguous 70 MHz of common bandwidth feeding all equipped
demodulators in the chassis. The Rx Frequency Range is the starting frequency for this range –
the occupied bandwidth of the carrier terminating into each demodulator must therefore fall
completely within this 70 MHz of bandwidth
The valid operating range for each item in this section is noted in parentheses.
•
Rx RF Frequency (0 to 67080 MHz) – This is the frequency at which the terminal receives
from the satellite. Once you enter a non-zero Rx RF Frequency or Rx L-Band Frequency value
and enter the LNB LO Mix and LNB LO Frequency, the demodulator’s Rx L-Band or RF
Frequency will be automatically configured.
Enter the Rx RF Frequency in MHz. Click [Submit] . Upon submission, if you enter the LNB LO
Frequency, the resulting Rx RF Frequency displays.
If the LNB LO Frequency is left at the default configuration of zero, the Rx RF Frequency will
not be calculated.
The LNB LO Mix and LNB LO Frequency entries are provided for calculation
purposes only. LNB configuration is not updated as a result of configuring these
parameters.
•
LNB LO Mix – Use this drop-down list to select the LNB LO (Low Oscillator) Mix as Upconv
(SUM): RF=LO+LBand or DownConv (Diff): RF=LO-LBand .
Consult your LNB adjunct product datasheet or its Installation and Operation
Manual for the type of LNB (Upconverter [Sum] or Downconverter [Diff]) being
used.
•
LNB LO Frequency – Enter the known LNB Rx LO (Low Oscillator) Frequency in MHz.