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CDM-740 Advanced Satellite Modem
Front Panel Operation
5.9
SELECT: ODU
The CDM-740 modem is able to interface with various ODUs (Outdoor Units). These are:
•
•
The ODU configuration menus allow the user to set up power supplies, a 10 MHz reference and
low/high current alarm thresholds for the BUC and LNB. LO menus for the BUC and LNB allow
the user to set up the up-convert and down-convert parameters for the BUC and LNB so that the
user can view the satellite frequencies as well as the modem IF input/output frequencies.
BUC: BUC_LO Power 10M-Ref Alarm Monitor
LNB: LNB_LO 22K-Tone Polarity
Use the
◄ ►
arrow and ENTER keys to select a submenu. Note the following:
For
BUC
(Top line)
LNB
(Bottom line)
5.9.1
ODU: (BUC:) BUC_LO
BUC_LO: 00000.000 MHz
Terminal Mix: [+]
On the top line, the user may enter the BUC LO frequency for the up conversion. Entering a non-
zero value for BUC LO will cause the Tx-IF frequency menu to show LO and Satellite frequencies.
Edit the BUC LO frequency by using the ◄ ► arrow keys to select the digit to be edited, then use
the
arrow keys to set the value of that digit. The valid LO range is 3000 to 65000 MHz.
▲ ▼
On the bottom line, the Terminal Mix sets the polarity for the upconversion mix in the BUC:
•
•
Note:
Satellite frequency = LO frequency +/- modem frequency
To set the sign for the Terminal Mix, use the ◄ ► arrow keys to navigate to the setting, then use
the
arrow keys to edit the Terminal Mix setting as positive [+] or negative [–].
▲ ▼
Note: The TTF: (Transmit Terminal Frequency) value is provided on a 'status only' basis.
L-Band BUC (Block Upconverter);
L-Band LNB (Low Noise Block Downcoverter).
Submenu
Permits user to...
BUC_LO
... enter a BUC LO (local oscillator) frequency and (+/-) sign.
Power
... set BUC power supply parameters.
10M-Ref
... control the BUC 10MHz Reference.
Alarm
... control BUC high and low alarm limits.
Monitor
... monitor BUC power supply and current parameters.
LNB_LO
... enter an LNB LO (local oscillator) frequency and (+/-) sign.
22K-Tone
... set the 22KHz tone outbound from L-Band connector per DiSEq 4.2
... control the LNB DC Power. Note the following:
•
Polarity
•
•
[+] indicates a high side, inverting mix;
[–] indicates a low side, non-inverting mix.
OFF = DC Power is off
Horizontal is on 18V
Vertical is on 13V.
TTF:
+1950.0000
5–27
Revision 0
MN-CDM740
◄►
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