LB-EO Rev.
3
4
Connections
The Flashlink LB-EO has a dedicated connector module: LB-EO-C1. This module is mounted
at the rear of the sub-rack. The module is shown in the figure below.
Monitor
Fibre optical output
RF input
LNB power supply
GPI
Figure 3: Connector module for L-band.
In typical use, an LB-EO / LB-OE module at each end will be used. An LNB is connected to
the F-connector of the LB-EO, and a satellite tuner is connected to the F-connector of the LB-
OE. The voltage/22kHz output from the satellite tuner, can not be transferred on the fibre
between LB-EO and LB-OE, because this signal goes the other way. The LB-OE can
nevertheless detect voltage and/or tone, and put them to the GPI output on the LB-EO.
Using a separate communication line (two digital signals using D422MG or similar), these
signals can be transferred to the LB-EO.
LB-EO tone/voltage output on the RF-connector can be controlled is three different ways:
directly using GYDA, DIP switches or the GPI inputs (see chapter 3.1 for DIP switch settings).
The LB-OE will always detect the voltage/tone from the satellite tuner or other equipment,
and set the GPI according to the detected tone and voltage. A 22 kHz tone on top of the
LNB power supply indicates high band (11.7-12.75 GHz) and no tone is for low band (10.7-
11.7 GHz).
Vertical polarization is chosen with a voltage less than 15 volts, typically 13 volts. Most LNBs
will set vertical polarization within a voltage window (for instance from 11.5 to 14.2 volts
dependant of the LNB). Accordingly the horizontal polarisation is voltage greater than 15
volts, typically 18 volts (for instance from 15.8 to 19.0 volts). If the voltage is near 15 (for
instance between 14.2 and 15.8), the polarization will be uncertain. The example voltages
are LNB manufacturer dependant, please check the user manual for the LNB voltage
thresholds. If the RF coaxial cable is long, there will be a DC loss. By adding one volt out
from the LB-EO, longer cables can be used without risking getting the wrong polarization.
This configuration is called LLC (long line compensation).
There is also a power connection for LNB. Connect pin 4 to a positive voltage (+12V to
+24V) and pin 1 to power supply ground. The frame power supply can only supply 15W
totally on +15V, and external power supply must be used if 15W is exceeded. LNBs can draw
up to 9W, please check the LNB’s user manual for current consumption.
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