Comtech EF Data CDM-570A - Manual (Page 131)

CDM-570A/570AL Satellite Modem with Optional Packet Processor MN-CDM570A
Front Panel Operation Revision 2
6–27
6.3.2.4.5 (CONFIG: Rx) Frq (Frequency)
Rx IF Freq:1156.3456 MHz
(◄ ►,▲ ▼,ENT)
To edit the Receive IF Frequency, use the ◄ ► arrow keys to select a digit, and then use the
▲▼arrow keys to change that digit. Press ENTER.
For the CDM/R-570ALonly: The valid range of frequencies is from 950 to 2250 MHz, in steps of
100 Hz.
If the Rx IF Frequency is set above 2000 MHz, and you then set the modem to
CDM-570 Compatible Mode, the Rx IF Frequency will be reset to 1201 MHz. Be sure
to reconfigure your Tx IF Frequency as needed.
Note that, if using the CONFIG: ODULNB menus and you select an LNB frequency other than
zero and define whether the mix is high-side or low-side, the display changes to include the
calculated Transmit RF frequency of the modem/LNB combination. Also, note that as you edit Rx
IF frequency, the RF frequency updates automatically:
Rx IF Freq:1156.3456 MHz
RF=14156.3456(◄ ►,▲ ▼,ENT)
For the CDM-570A only: The range of frequencies permitted is from 50 to 90 MHz and from 100
to 180 MHz, in steps of 100 Hz, as this example shows (note that the modem displays leading
zeros to maintain compatibility with the L-Band firmware):
Rx IF Freq:0075.9876 MHz
(◄ ►,▲ ▼,ENT)
6.3.2.4.6 (CONFIG: Rx) Acq (Acquisition Range)
Demod Acquisition Range:
+/- 010 kHz (▲ ▼,ENTER)
The Demod Acquisition Range determines the amount of frequency uncertainty the
demodulator will search over in order to find and lock to an incoming carrier.
To edit the search range value, use the ◄ ► arrow keys to select a digit, and then use the
▲▼arrow keys to change that digit. Press ENTER.
For the CDM-570AL, the range varies according to the symbol rate:
• From ±1 kHz to ±32 kHz for rates less than or equal to 625 ksymbols/sec.
• From ±1 kHz to ±200 kHz for rates greater than 625 ksymbols/sec.
For the CDM-570A, the range is from ±1 kHz to ±32 kHz.