Seite 93 - TELE-satellite-1201

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93 —
12-01/2012 —
TELE-satellite International — The World‘s Largest Digital TV Trade Magazine
1. SPAROS Signal Analyzer detected correctly all eight
SCR frequencies when connected to SUS 558133 NF SCR
2. The lowest SCR frequency (1068 MHz) activated – measured
directly at the output of SUS 558133 NF SCR Multiswitch.
3. All but one SCR frequencies activated on the output
number 2 of SUS 558133 NF SCR Multiswitch in the single
cable mode.
A valuable feature of
the SUS 5581/33 NF is its
versatility in powering it
up. SPAUN supplies a wall
mount power supply unit
but if this is not practical in
your installation, you can
power the multiswitch via
its terrestrial trunkline. By
the way, the included pow-
er supply unit have a con-
venient plug adapters what
combined with its high in-
put voltage range (100-240,
V 50/60 Hz) makes it truly
worldwide. There are also 5
pieces of 75 ohm termina-
tors included in the package.
You attach them to the trunk
outputs if they are not used
for cascading.
Although the UNiSockets
are much simpler products
than the SCR multiswitch,
their performance also
counts in the whole system.
We got tree socket types.
Although they look identical
except for the type number
printed on them, they dif-
fer in the insertion and tap
losses. UNiSocket 310 has
the lowest tap loss – only 10
dB, but its insertion loss is
the highest from the three
models – 3 dB. You’d bet-
ter choose this model for the
most distant socket from the
SCR switch. Model 318 has
the highest tap loss – 18 dB
but the lowest insertion loss
– only 1.5 dB. This model
should be considered for the
sockets located close to the
SCR multiswitch. UNiSocket
314 is an interim model with
moderate tap loss – 14 dB
and insertion loss – 2 dB.
All those parameters are the
typical values and according
to the product specifications,
you should be ready to ac-
cept +/- 2 dB tolerance of
the tap loss for every model.
We started our tests with
measuring the sockets. The
results were very satisfac-
tory for the insertion loss –
all three models had lower
average loss than specified.
Model 310 had the average
insertion loss 2.49 dB, mod-
el 314 – 1.99 dB and model
318 – 1.66 dB. The loss vari-
ation was small in the whole
IF frequency range (950-
2150 MHz). We can say that
the sockets were 0.5 dB bet-
ter than specified.
When we took the meas-
urements of the tap loss, the
average results were still in
the specifications: 11.96 dB
for 310, 15.85 dB for 314
and 17.98 dB for 318. but
slightly higher than typical
We built a test distribution
system then. A high output
power quad LNB was driving
our SUS 5581/33 NF. Later,
we switched to a Quattro
LNB and everything worked
equally good. The SCR mul-
tiswitch was configured for
one output. We connected
a quite long cable (over 30
meters) to its output. The
first UNiSocket 318 was con-
nected to the cable end and
after this socket we connect-
ed the other seven ones:
2 x 318, 3 x 314 and 2 x
310. Between the sockets
we connected cables of vari-
ous lengths: from 30 cm to
6 meters. The whole system
from the SCR multiswitch
to the last socket measured
about 50-55 meters.
A cable of such length at-
tenuates the signal by about
15 dB and usually does not
pose a problem for a normal
satellite reception in which
an LNB is routed directly to
a receiver. However, in our
case, every socket installed
on the cable added its at-
tenuation (insertion loss).
The SCR multiswitch has
automatic gain control that
regulates its output signal to
about 90 dBµV output if only
the input signal from the
Quad or Quattro LNB is in
the range 65-90 dBµV. The
above table presents the
signal levels we achieved at
each of the sockets.
We were quite anxious
when we connected our
receiver. Would it be able
to lock to the signal? We
used a modern Icecrypt
STC6000 HDPVR. The re-
ceiver was locking to the
signal and showing channel
video without any problem,
no matter to which socket
we connected it and which
SCR frequency we chose. Its