TWIN DVBS2-QAM
Important safety instructions
General installation conditions
• Before handling or connecting the equipment, please read this
manual.
• In order to reduce the risk of fire or electric shock, do not expose the
equipment to rain or moisture.
• Do not take the cover off the equipment without disconnecting it
from the mains.
• Do not obstruct the equipment's ventilation system.
• Please allow air circulation around the equipment.
• The equipment must not come into contact with water or even be
splashed by liquids. Do not place containers with water on or near the
equipment if it is not adequately protected.
• Do not place the equipment near sources of heat or in excessively
moisture conditions.
• Do not place the equipment where it may be affected by strong
vibrations or knocks.
• This symbol indicates that the equipment complies with
the requirements of CE mark.
NOTE: The complete user manual is available in the CD
that is provided with the product.
Technical specifications
Input Frequency:
Input Level:
Satellite
Frequency Steps:
Demodulator
Input and Output connectors: "F" female
Input Impedance:
LNB Power Supply:
Throughput Losses:
Modulation Format:
Symbol Rate:
QAM Modulator
Roll-off Factor:
Block Code:
Output Frequency:
Frequency Steps:
UP-Converter
Phase Noise:
Output Level:
Adjustable Output Level:
Power Supply:
General
Index of Protection:
- The power source can supply a maximum of seven TWIN DVBS2-QAM modules.
- Whenever the demand of power exceeds 4A (max. current for each output), it is necessary to distribute it between the two powering outputs of the PSU.
- The technical characteristics described are defined for a maximum ambient temperature of 45°C (113ºF). Forced ventilation is used for higher temperatures.
Inputs/Outputs/Connections description
The unit (Fig. 1) is provided with:
1. IF satellite input
2. IF satellite output
3. RF input
4. RF output + 2 CH QAM (module A & module B)
5. Powering BUS connectors
6. Status LED
7. Control BUS connectors
8. Programmer/PC socket
Introduction
The TWIN DVBS2-QAM unit consists of two transmodulators within the
same chassis. Each module processes a satellite transponder (to one of the
modulation formats defined in DVB-S2: QPSK or 8PSK) and demodulates it to
obtain a MPEG2 transport stream which is then modulated in QAM format
and converted to a RF output channel (UHF or VHF and maximum bandwidth
of 8MHz).
In some cases, especially with DVBS2 input signals, the satellite input rate
may be too high to accommodate a QAM signal to its output. Therefore, it is
necessary to choose between the services available at its input, which ones
will be distributed at the output's unit, thus eliminating the unwanted ones
and reducing the bit rate. By integrating two transmodulators, it is possible
the division of an incoming DVB-S2 transponder, into two output QAM
channels, and maintaining all transponder's services.
This unit allows the stream stuffing because, in many cases, QAM receivers
perform the search in the frequency band having only a single symbol rate
as a variable parametre, eg 6,875 or 6.9 Mbaud. The equipment can provide
this symbol rate, regardless of the bit rate of the input signal, making the
stuffing of the MPEG2 transport stream.
950 - 2150 MHz
49 to 84 dBµV (-60 to -25 dBm)
1 MHz
75 ohm.
13/17V/ OFF 22KHz (ON/OFF)
< 1,5 dB typ.
16, 32, 64, 128, 256 QAM
6,9 Mbaud max
15%
Reed Solomon (188, 204)
46- 862 MHz (Select.)
250 KHz
90 dBc/Hz @10KHz typ
80 ±5 dBµV
>15 dB
24V
IP20
DVB-S2 (QPSK, 8PSK)
Modulation:
DVB-S (QPSK)
2 to 42.5 Mbaud (DVB-S)
Symbol Rate:
10-30 Mbaud (DVB-S2)
FEC Input:
LDPC (9/10, 8/9, 5/6, 4/5, 3/4, 2/3, 3/5, 1/2)
FEC Output:
BCH (Bose-Chaudhuri-Hocquenghem)
Roll-off Factor:
20%, 25%, 35%
Input SWR:
10 dB min.
Scrambling:
DVB ET300429
Interleaving:
DVB ET300429
Bandwidth:
8 MHz max.
Spectral inversion:
Normal / Inverted (Select.)
Throughput losses:
< 1,5 dB typ.
Return Losses:
> 12 dB typ.
Input and Output
"F" female.
connectors:
Output Impedance:
75 ohm.
Spurious level:
55 dBc min. >60 dBc typ.
550 mA typ. (without powering LNB)
Consumption 24V:
800 mA typ. (powering LNB)
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