05-06/2015
TELE-audiovision.com/15/05/tekniksat
14
TELE-audiovision International — The World‘s Leading Digital TV Industry Publication
— 05-06/2015
—
TELE-audiovision.comTEST REPORT
Optical System
Fiber optics are used more
and more often when there
is a need to distribute satel-
lite signals to a large number
of receivers. That’s because
fiber optic cables attenuate
signal much less than clas-
sical coaxial cables and add
very little noise to the signal
they convey. It is relatively
easy to find components for
such a system when you
want to distribute the signal
from one chosen satellite.
But if you want to deliver sig-
nals to a high number of re-
ceivers from not one but four
satellites plus a signal from a
terrestrial antenna, the job is
no longer that easy. Time for
Tekniksat Electronics! They
have developed an exten-
sive product portfolio built
around fiber optic distribu-
tion components.
For this test report we de-
cided to build a simple dis-
tribution system and used
these components made by
Tekniksat: TPF 41-2 Opti-
cal Transmitter, TFS 1/32 FC
Splitter and TFM 41/10 C Op-
tical Multiswitch.
The TPF 41-2 Optical
Transmitter is in fact a rack
mounted signal amplifier
and converter. Its job is to
amplify and convert satel-
lite signals coming from 4
different LNBs and 1 terres-
trial input to a single optical
signal. Concerning LNBs, you
can use either Quattro or
Quad LNBs. So, it is easy to
figure out that the TPF 41-2
has 4 x 4 = 16 satellite in-
puts designated with HH, HV,
LH and LV symbols. The 17th
input is for the terrestrial
antenna input, which can be
either an over-the-air recep-
tion like DVB-T/T2 or for con-
necting to a cable system
(DVB-C). Of course, that’s
because terrestrial and cable
TV share the same frequen-
cy band: 47-870 MHz. In this
test report we decided for
connecting the system to a
terrestrial antenna.
The unit provides 23 dB
gain for the satellite signals
and 15 dB gain for the ter-
restrial signal. You can ad-
just each input with a mul-
titurn potentiometer and the
adjustment range is 15 dB.
If needed, you can switch off
the LNB power. If you do not,
then the four LNBs will get
the suitable 13 or 18 V volt-
age for polarization switching
and 22 kHz signal for band
switching from the TPF 41-2.
The TPF 41-2 Optical Trans-
mitter is well finished off and
looks robust and solid. A
cooling fan installed on the
Optical Distribution System
sands of meters and/or split
it to many branches.
In our test we used a 1-to-
32 splitter. Namely it was the
TFS 1/32 FC. The ideal 1-to-
32 splitter would produce at
each output a 1/32 fraction
of the input power. Unfortu-
nately, every practical device
has some additional losses.
In case of the TFS 1/32 FC
those additional losses are
really marginal. The inser-
tion loss is only 16.8 dB
(vs. theoretical 15.05dB).
The splitter itself is a rather
rear panel helps preventing
overheating although during
our tests we did not notice
excessive warming. It may
be useful when the unit is in-
stalled in a cramped 19 inch
cabinet though.
The TPF 41-2 has one SC/
APC optical port and gener-
ates a strong output signal:
4 mW (6dBm). This is the
entry point for the fiber optic
network. With such a strong
signal you can transfer the
signal to very remote loca-
tions: hundreds if not thou-
Optical Distribution System
Perfect to feed hundreds of subscribers with
identical quality signals