TELE-audiovision - The World’s Largest Digital TV Trade Magazine - page 72

TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine
— 1 -12/2013
SCR Multiswitch
In part 1 of this article
(see TELE-audiovision 09-
10/2013), we presented two
SPAUN single cable router
(SCR) multiswitches: the
and the SUS 5581 F. This
time we take a closer look
at yet another SPAUN SUS
models, namely models
that vary in number of in-
puts/outputs as well as in
the number of receivers
one can connect to them.
The models are called: SUS
5581 NFA, SUS 5581/33
SUS 4481 F, SUS 5541 F and
SUS 5541 NFA.
But let us first stop for a
while to explain what the
numbers and letters in a
model designator stand
for. The first two digits tell
you the number of inputs
and trunk outputs. So, “44”
mean four satellite inputs
(from a Quattro LNB) and
four trunk outputs: Vertical
Low, Vertical High, Horizon-
tal Low and Horizontal High.
If a multiswitch symbol con-
tains “55”, this means that
you have an additional input
and trunk output for a ter-
restrial signal, in most cas-
es, taken from an outdoor
TV antenna.
The second pair of digits in
a model number designate
the number of single cable
outputs and the number of
receivers you can connect
to them. “41” means: one
output line to which you can
connect up to four receiv-
ers. “81” is used when there
is one line to which 8 receiv-
ers can be connected. And if
you read “81/33”, it means
that a multiswitch can be
used either in a mode with
one output line and eight
receivers or in a mode with
three output lines for up to
3 receiver on every line. The
desired mode is then se-
lected with a rotary switch
mounted on the top cover of
a multiswitch.
The letters “NFA” mean
that an SCR multiswitch
has embedded amplifiers
at every satellite input. Be
careful not to overdrive
such models. If you direct-
ly connect a contemporary
Quattro LNB to such multi-
switch with short coax ca-
bles there is a great chance
that you will exceed the 80
dBμV limit for NFA devices.
This holds true for strong
transponders like ASTRA or
HOTBIRD in Europe. In such
a case, signal quality on all
outputs will decrease sig-
nificantly. NFA models are
to be used as the third or
even fourth multiswitch in
a cascade where the signal
is attenuated by passing the
previous devices.
The term “LEGACY” is
used for the devices having
3 outputs and two modes of
operation: 8x1 or 3x3. Such
devices, when switched
to 8x1 mode, will gener-
ate classical (legacy) mul-
tiswitch signals at the two
outputs not used in single
cable mode. In this way,
those outputs are not dor-
SUS 5581 NFA, SUS 5581/33 NFA LEGACY,
SUS 4441 F, SUS 4481 F, SUS 5541 F
and SUS 5541 NFA
Best products for creating a reliable SCR
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