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3.2 Power supply
OPT-RX QUAD MINI: The optical receiver can be powered by STB (set-top-box) or with an external power supply to DC IN optional
input.
OPT-RX 4 MINI: the power supply is provided via SAT outputs.
3.3 Fibre optic connection
ATTENTION: Direct connections are not allowed between the OPT-TX DT and OPT-RX QUAD MINI/ OPT-RX DT 4 MINI
unless the correct line optical attenuators are used, because the maximum input power into the receivers can not exceed -8dBm.
An optical signal reader must be used to check the optical input level to the receivers.
Use the SC-APC -> MINI links (PR ADAPT, code 287226) to connect the OPT devices to the optical distribution (VOV and VOT
devices).
Attention: To conserve and protect the contact surfaces of the optical connectors the bushing and ferule protectors should be
left in position until the connections are made or can be cleaned using the correct tools.
4. USER’S INSTRUCTIONS
4.1 Dimensioning a Fibre Optic system
The optical attenuation range allowed is 15/ 21 optical dB. Refer to the product specifications to calculate the optical attenuations
for the devices.
The receivers can guarantee that the correct level of TV and SAT signals are available to the end users sockets. This guarantee
is on the proviso that the input level of the optical signal is between -8dBm and -14dBm and the RF signal incoming to the
OPT-TX DT complies with the specifications of its manual.
ATTENTION:
•
Direct connections are not allowed between the OPT-TX DT and Receivers, unless the correct line optical attenuators
are used.
•
An optical signal reader must be used to check the optical input level to the receivers and to prevent damaging the receiving
photodiode (damage can be caused if the optical input signal is higher than 0dBm).
4.2 Output levels to the optical receiver
The output level to the OPT-RX optical receivers depends on the number of signals transmitted through the fibre and the optical
attenuation of the section.
Remember that 1dB of optical fall equals 2dB of attenuation to the electric level (RF).
Below some reference levels are given for the output signals to the receivers:
OPT-RX QUAD MINI
Shown below are some of the reference levels of the signals output to the receiver OPT-RX QUAD MINI
TV (DVB-T/CATV)
The overall output power is -32dBm (77dBµV) with 21dB of optical attenuation which means that the fewer multiplexes that are
transmitted, the better the output level and quality.
RF output level per MUX
No. of Muxes
Receiver optical Input -8dBm
Receiver optical Input -14dBm
40
81dBµV
69dBµV
16
84dBµV
72dBµV
8
87dBµV
75dBµV
4
90dBµV
78dBµV
Table 1: Indications of output levels to the OPT-RX QUAD MINI – TV signal
Note: 1dB optical equals 2dB at electric level (RF).
