Verify Frequency Values - Comtech EF Data CMR-5975 Installation And Operation Manual

Digicast Media Router S2 Receiver CMR-5975 (MR-S2)
Setting Up a Digicast Digital Satellite Receiver
D.3

Verify Frequency Values

The information gathered in the previous section will become the proper parameters entered into
the Digicast receiver. However, before this can be done successfully, several values must be
verified:
1. Verify the downlink frequency provided falls into the proper band:
a. C-Band – 3,700 to 4,200 MHz
b. X-Band – 7,000 to 12,500 MHz
c. Ku-Band –11,000 to 18,000 MHz
d. Ka-Band – 18,000 to 40,000 MHz
If the downlink frequency does not fall within proper band, contact the space-link provider for
clarification.
2. Determine the values to set for the LO and downlink frequency on the Digicast satellite receiver.
There are two ways the frequencies can be loaded into the Digicast satellite receiver: 1) Directly
entering the downlink and LO frequencies, or 2) by entering the values as L-Band frequencies.
1) Entering the values directly provides the most convenience, since the user simply enters the
downlink frequency and LO directly into the Digicast satellite receiver.
2) Entering the values as an L-Band frequency requires some math to be performed, but allows those
who are more comfortable with L-Band values to use those familiar frequencies.
To use L-Band frequencies in the configuration, the LO frequency must be set to 0 MHz. The
downlink frequency is determined by taking the absolute difference of the actual downlink frequency
at (C-, X-, Ku- or Ka-Band) and subtracting the two and using the absolute result (a non-negative
number). Once this number has been found, the difference will be the L-Band frequency that can be
entered into the downlink frequency on the Digicast satellite receiver. The following examples are
given:
Example 1:
Ku-Band
LO = 10,750 MHz
Downlink Frequency = 11,895 MHz
L-Band Frequency = | 11,895 MHz – 10,750 MHz |
L-Band Frequency = 1,145 MHz
Example 2:
Ku-Band
LO = 10,600 MHz
Downlink Frequency = 12,010 MHz
L-Band Frequency = | 12,010 MHz – 10,600 MHz |
L-Band Frequency = 1,410 MHz
Example 3:
C-Band
LO = 5,150 MHz
Downlink Frequency = 3,920 MHz
L-Band Frequency = | 3,920 MHz – 5,150 MHz |
L-Band Frequency = | - 1,230 MHz |
L-Band Frequency = 1,230 MHz
D–4
Revision 3
MN-CMR5975-IOM