Fracarro OPT-TX51 Instrucciones De Funcionamiento página 18

OPTICAL
FIBER LINK
OPT-TX51
Optical attenuation of the splitter:
1×2 --> 3,2 dB
1×4 --> 6,4 dB
1×8 --> 9,6 dB
1×16 --> 12,8 dB
Evaluation of the signal/noise ratio (CNR)
Use table 2 and table 3 to determine the CNR value (signal/noise ratio) of the optical link. The output
level and the CNR corresponding to any possible input level are shown as regards to each level of opti-
cal attenuation. The Pin(dBµV) line must be considered as follows: if you have to transmit N channels,
each channel must be set to a level of X dBµV at the optical transmitter input.
EXTERNAL
TRANSMITTER
FOR AUXILIARY
CHANNEL
Figure 2 – Use of the auxiliary channel.
4.1 QUICK GUIDE TO DESIGN OPTICAL LINKS
Splitter(s)
Optical attenuation of the fiber:
Wave length
Wave length
Table 1 – optical attenuation calculation of the link
OPTICAL
FIBER LINK
To SAT distribution
network
: 1310 ± 40 nm --> 0,4 dB/km
: 1550 ± 40 nm --> 0,25 dB/km
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EXTERNAL
RECEIVER
FOR AUXILIARY
CHANNEL
To TV distribution
network
OPT-RX51
OPT-RX51
OPT-RX51
OPT-RX51