Comtech EF Data SNM-1010L - Manual (Page 114)

SNM-1010L Data/Control Modem Revision 0
Front Panel Operation MN/SNM1010L.OM
3.4.6 TX Terminal (Future Provision)
Note: The SNM-1010L automatically configures itself using the L-Band frequency
range. In the future, C-Band/K-Band/Ku-Band frequency ranges may be supported.
Currently the TX terminal LO should be set to zero (0).
This menu allows the user to enter the LO (always in MHz) of the ODU unit. When any
non-zero frequency is entered, the low and high limits of the TX-IF Frequency will have
new ranges (from L-Band to C-BAND/K-BAND/Ku-BAND).
The following formulas are used to calculate the TX frequency range when the MIX is
set "-":
TX Freq(MAX) =
LO - 950 MHz
TX Freq(MIN) = LO - 1750 MHz
The following formulas are used to calculate the TX frequency range when the MIX is
set "+":
TX Freq(MAX) =
LO + 1750 MHz
TX Freq(MIN) = LO + 950 MHz
L-Band frequency of the modem is then programmed via the following formula:
Freq (L-Band) = ABS (TX Freq - LO).
Examples:
LO = 4900 MHz, Mix = "+"
------------------------
TX Freq(Max) = 4900 + 1750 = 6650 MHz
[L-Band Freq = 1750 MHz]
TX Freq(Min) = 4900 + 950 = 5850 MHz [L-Band Freq = 950 MHz]
LO = 5760 MHz, Mix = "+"
------------------------
TX Freq(Max) = 5760 + 1750 = 7510 MHz
[L-Band Freq = 1750 MHz]
TX Freq(Min) = 5760 + 950 = 6710 MHz [L-Band Freq = 950 MHz]
LO = 7375 MHz, Mix = "-"
------------------------
TX Freq(Max) = 7375 - 950 = 6425 MHz
[L-Band Freq = 950 MHz]
TX Freq(Min) = 7375 - 1750 = 5625 MHz [L-Band Freq = 1750 MHz]
LO = 7300 MHz, Mix = "-"
------------------------
TX Freq(Max) = 7300 - 950 = 6350 MHz
[L-Band Freq = 950 MHz]
TX Freq(Min) = 7300 - 1750 = 5550 MHz [L-Band Freq = 1750 MHz]
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