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IRD-2600 / IRD-2800
Integrated Receiver Decoders
P/N 2349-72784-00
Page 13
In Figure B-2 a distribution amplifier is used that limits the frequency reception range of the
whole system (IRDs, distribution amplifier and satellite dish with LNB). The distribution
amplifier only passes frequencies between 850 MHz up to 2000 MHz while the IRDs are
capable of tuning to frequencies between 950 MHz up to 2150 MHz. The IRDs will not
receive any signal between 2000 MHz and 2150 MHz because the distribution amplifier
blocks this range. The calculation of the reception range of this example set-up is as shown
below:
Combined frequency range = 950 MHz . 2000 MHz. (Amp IRD).
(Example) LNB frequency = 10750 MHz.
System Input frequency range = (950 + 10750) (2000 + 10750) MHz
= 11700 MHz .. 12750 MHz.
B.4
Calculating the L-Band Frequency
To calculate the L-Band Frequency:
L-Band frequency = FS - FLO
Where:
•
FS = transponder transmitting frequency.
•
FLO = LNB local oscillator frequency.
Examples:
•
For LNBs with a single Local Oscillator: 10 GHz
•
For universal (Ku band) LNBs:
Low Band Local Oscillator: 9.750 GHz
High Band Local Oscillator: 10.600 GHz
The available L-Band frequency range is 0.950000 to 2.150000 GHz
The following is a numerical example:
For the group of station programs handled by the TV1 multiplexer, the transponder frequency
is 12.012 GHz.
•
For LNBs with a single Local Oscillator:
L-Band frequency = 12.012000 - 10.000000 = 2.012000 GHz
•
For Universal (Ku band) LNB oscillator selected:
L-Band frequency = 12.012000 - 10.600000 = 1.412000 GHz