Comtech EF Data CDM-840 - Manual (Page 103)

CDM-840 Remote Router Revision 2
Ethernet-based Remote Product Management MN-CDM840
6–35
Modulator Frequency
The Tx Frequency Calculator provided here conveniently allows you to start from either the Tx
RF or Tx L-Band/IF Frequency and calculate the “other” frequency. If the BUC LO Mix, BUC LO
Frequency, and one of the desired frequencies are known, then the other can be calculated.
This calculator is intended to remove any guess work associated with the modem’s L-Band/IF
Frequency to the terminal’s RF frequency (or vice versa).
The acceptable/valid operating range for each item in this section is provided in parentheses.
• Tx RF Frequency (0 to 67150) – This is the frequency at which the terminal is transmitting to
the satellite. Upon configuring this to a non-zero value, as well as entering in the BUC LO
Mix and Frequency, the modem’s L-Band or IF frequency will be automatically configured.
Enter the Tx RF Frequency in MHz. Click [Submit]. Upon submission, if the BUC LO
Frequency has been entered, the resulting Tx RF Frequency will be displayed.
If the BUC LO Frequency is left at the default configuration of zero, the Tx RF Frequency will
not be calculated.
The BUC LO Mix and BUC LO Frequency entries are provided for calculation
purposes only. BUC configuration is not updated as a result of configuring these
parameters.
• BUC LO Mix – Use this drop-down list to select the BUC LO (Low Oscillator) Mix as Upconv
(SUM): RF=LO+LBand or DownConv (Diff): RF=LO-LBand.
Consult your BUC adjunct product datasheet or its Installation and Operation
Manual for the type of BUC (Upconverter [Sum] or Downconverter [Diff]) being
used.
• BUC LO Frequency – Enter the known BUC Tx LO (Low Oscillator) Frequency in MHz.
Consult your BUC adjunct product datasheet or its Installation and Operation
Manual for the LO Frequency.
• Tx L-Band Frequency (950 to 2150 MHz for L-Band, 50 to 180 MHz for IF) – Enter the L-Band
or IF-Band frequency in MHz. Click [Submit].