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TELE-satellite International — The World‘s Largest Digital TV Trade Magazine
— 12-01/2012
— www.TELE-satellite.com
enter its installation menu
and check if you can set its
LNB to “SCR” “UNiSEqC” or
“Unicable” type. The menu
should also offer you the
possibility to program the
SCR frequencies or to detect
them automatically.
During the system con-
figuration, we need to assign
a unique SCR frequency to
each receiver. Two receiv-
ers can not operate on the
same frequency. When using
SUS 5581/33 NF in one out-
put configuration, the avail-
able frequencies are: 1068,
1284, 1400, 1516, 1632,
1748, 1864 and 1980 MHz.
The best idea is to assign
the lowest frequency (1068
MHz) to the receiver which
is the last one on the cable
and thus must overcome the
highest cable attenuation.
Cable attenuation increases
with frequency, so to make
“life easier” for the last re-
ceiver, we should keep its
operating frequency as low
as possible. Of course the
last but one receiver should
work on 1284 MHz and so
on. The very first one should
operate on 1980 MHz.
If a three cable installation
makes more sense in your
particular location, the fol-
lowing frequencies are avail-
able: 1068, 1284 and 1400
MHz on output no. 1, 1516,
1632 and 1748 MHz on out-
put no. 2 and 1864, 1980
and 2096 MHz on output
no. 3. Of course, the laws of
physics do not change when
you use this configuration,
so use output no. 3 for the
shortest cable and output
no. 1 for the longest cable.
And, as explained above, the
further is the receiver from
the SCR multiswitch the
lower should be its operating
frequency.
All these frequencies are
not only listed in the well
written and detailed user
guide but also on the top
cover of the SUS 5581/33
NF. Like all other SPAUN
multiswitches, also this unit
is perfectly finished off and
its labels could not be more
self-explanatory. You can
see it for yourselves in the
pictures presented alongside
this report.
The SCR multiswitch is
cascadable what means
that you can connect anoth-
er SUS 5581/33 NF to the
trunk outputs and increase
the number of the receivers
in the installation. Of course,
each receiver (or receiver
tuner) will be fully independ-
ent and capable of receiving
any channel from the satel-
lite your antenna, equipped
witha Quad or Quattro LNB,
is aimed at. While one multi-
switch should be a sufficient
solution for a family house,
you may need to cascade a
few multiswitches to serve a
multistory building.
Speaking of the distribu-
tion system configuration,
it is worth mentioning that
you are not limited to either
1x8 or 3x3 configurations.
For example, if you split the
single output to two lines,
you can get the configura-
tion 2x4. You only need to
remember that the splitter
must support the IF frequen-
cy range (950-2150 MHz)
and have a DC pass. This is
clearly explained in the user
guide.
An important thing you
should remember is that the
input signal from Quad or
Quattro type LNB should be
rather high (65~90 dBµV).
This is not a problem if you
are going to receive a strong
European satellite like AS-
TRA 1 on 19.2° and you
have enough room to install
90 cm dish, but if this is a
weaker satellite, you should
think of either a bigger dish
(what is always advisable for
a “collective” reception) or
an additional amplifier be-
tween LNB and SCR multi-
switch input.
Exemplary installation
diagram with SPAUN
components (from the
brochure available on
www.spaun.com).