7 / 16
Digital terrestrial and satellite signals are fed to the optical transmitter (OSC 100) which
converts the electrical signals into optical signals, thus allowing distribution over long paths
using a
fi
bre-optic infrastructure. Suitable splitters (OVC xxx) and taps (OAC xxxx) are avail-
able for distribution of the optical output signal.
System functions
Notes on planning the
fi
bre optic system
When designing a
fi
bre optic system, it is important to consider the optical input levels to
the receiver (OEC 40 or OEC 44). To ensure that the system ful
fi
ls the required parameters,
appropriate attenuation must be calculated at each point. The optical output power from
the transmitter (OSC 100) is typ7 dBm. The input level of the optical receiver (OEC
40 and OEC 44) lies between -8 dBm and -14 dBm. This therefore provides an allowable
attenuation of the optical network of 15 to 21 dB.
The catalogue has a whole range of optical attenuators and taps/splitters which have
different attenuation values and enable the optimisation of the system. Please make use of
the Kathrein CLIKulator to plan and adjust your optical distribution network.
Attention:
• If directly connected without splitters or taps, attenuators must be used
between the OSC 100 and OEC 40/44. To avoid overload, the input power
on the receiver must not surpass -8 dB.
• If the quality of an input signal is not optimal or if a multi-carrier signal must
be distributed over a large coaxial distribution network, the optical budget
should be decreased.
• The level difference of a satellite transponder polarity (VL/VH/HL/HH)
should not exceed 4 dB. If the transponders have a gain slope on the
inputs of the OSC 100 and the level is high enough, in certain circum-
stances you can use the passive equalizer ERZ 60 to adjust the level
(use one ERZ 60 for each satellite polarisation). If a long coaxial cable
is used between the LNB and the OSC 100, you can adjust the level
and the gain slope (for each satellite polarisation) with the VWS 2500.
If several transmitters (OSC 100) are cascaded, a VWS 2500 satellite
distribution ampli
fi
er must be connected between the third and the fourth
OSC 100 and also between the
fi
fth and sixth in the cascade. The maximum
quantity is seven in the OSC 100 cascade.
Before connecting to the receiver (OEC 40 or OEC 44), check the optical
level of the signal on the optical fi bre using an optical power meter.
If the optical input signal is higher than 0 dBm, damage may be done to
the device!
