The FibreIRS DTT Processor from Global Invacom: 1. Filters terrestrial TV signals from antennas to remove noise and leave only the desired channels. 2. Amplifies the signals and improves the carrier-to-noise ratio by over 12 dB. 3. Has excellent frequency characteristics with sharp roll-offs and flat pass bands between channels.

1. TEST REPORT Fibre Optic System for DTT
FibreIRS DTT
Processor
of Global
Invacom
• excellent device to filter out any unwanted signals
• very simple device settings
• increases C/N parameters at the output
• useful for both coaxial cable systems and for the
new fibre optic systems
16 TELE-satellite International — The World‘s Largest Digital TV Trade Magazine — 06-07-08/2012 — www.TELE-satellite.com www.TELE-satellite.com — 06-07-08/2012 — TELE-satellite International — 全球发行量最大的数字电视杂志 17

2. TEST REPORT Fibre Optic System for DTT
A Set of Brick 06-07-08/2012
Wall Filters
FibreIRS DTT Processor
Delivery perfectly clean DTT signals for any
distribution system
www.TELE-satellite.com/12/07/globalinvacom
and Signal
Amplifiers
GlobalInvacom is a leading
company in introducing fiber
optics to satellite tv recep-
tion and TV distribution net-
works. Now they introduced
another very useful piece of
distribution system that can
be very beneficial not only
for fiber optics based sys-
tems but also for classical
coaxial cable systems.
GlobalInvacom’s DTT Pro-
cessor is a device installed
between a terrestrial anten-
na and the remaining part
of a distribution system.
Its most important function
is filtering the signal your
antenna picks up. Filter-
ing means passing through
the desired part of the fre-
quency spectrum where
the signals of interests are
transmitted while blocking
everything else from reach-
ing the output.
Why is this that impor- cal currents into light will be
tant? Thanks to the filtering, covered in our next test re-
the signal that finally comes port. Such converter if fed
to the input of your DVB-T or with very a noisy input sig- one. That’s because DVB-T
DAB receiver contains much nal might have a problem in TV operates in the 470-862
less noise. The probability generating well modulated MHz range while DAB in the
of picture pixelation, video/ light. Typically, the rule is: 217-230 MHz range. So it is DAB band is treated as one
audio glitches or complete garbage in = garbage out. possible to combine them in 13 MHz wide channel.
loss of reception is greatly If the signal quality is low one RF output. We are used nowadays
reduced. Starting with a at the input, it will become The basic version of the that one needs to connect
clean signal is even more even worse at the output. DTT Processor enables you a notebook PC to configure
important in a distribution Fortunately, filtering can be to select up to six different a professional system unit.
system based on fiber optic used to break this rule. TV channels. You can buy It is convenient when the
components. That’s because The FibreIRS DTT Pro- additional plug-in modules settings we need to do are
we need to convert the elec- cessor of GlobalInvacom and extend its functional- complex. But in the case of a
trical RF signal existing in accepts signals from two ity to eight DVB-T channels. DTT processor, the settings
the initial stages of such terrestrial antennas: one re- Each channel is 8 MHz wide are quite simple: the num-
system to modulated light. ceiving terrestrial TV signals in accordance with a typical ber of a channel you want
GlobalInvacom’s converter and the other digital audio terrestrial DVB-T-TV chan- to be passed through and
capable of changing electri- (DAB) signals. The output is nel plan. Consequently, the its signal gain. So it is really
18 TELE-satellite International — The World‘s Largest Digital TV Trade Magazine — 06-07-08/2012 — www.TELE-satellite.com

3. 1
good that GlobalInvacom’s 60 dBµV for DVB-T and not ■TELE-satellite Test Editor Jacek Pawlowski at
work. The FibreIRS DTT Processor is connected
processor does not require more than 65 dBµV for DAB. to a professional signal anaylzer. the analyzer‘s
you to connect to a PC. The output of every channel video output is fed into the laptop to generate the
screenshots for this report.
GlobalInvacom’s FibreIRS should be adjusted optimal-
DTT Processor not only ly to 70 dBµV if you connect
passes through the desired the GlobalInvacom ODU32
TV channels and blocks the RF-to-light converter to the
rest of the spectrum but processor. If your antenna
also amplifies their signal. has a built in amplifier – no
The unit is enclosed in a problem. The DTT Processor
metal case designed to be generates 12 V to power the
mounted on a wall on two amplifier.
screws. It has an external We started our test with a
2
AC/DC plug type adapter. real world signal. In our test
After unscrewing two screws location in Western Poland,
and removing the cover, you two DVB-T multiplexes are
get access to the interior of available. They are trans-
the processor. Every mod- mitted on channels E41 and
ule has an eight position DIP E45. The signal level was
switch you use to set the de- slightly above 66 dBµV – ex-
sired channel number (from actly as needed. As you can
21 through 69) and to turn see on the attached screen
a module on or off. A piece shots, the input signal con-
of foiled paper is attached to tained some undesired sig-
the internal surface of the nals too. These were some
cover. It’s a short list of op-
erating instructions, as how
analog TV channels which
are still transmitted as well
Expert Opinion
Very good adjacent channel separation
to turn the module on/off as some spurious signals
Flat pass band
and how to set the channel produced mainly in the an-
3 number. A few clicks with a tenna amplifier. But the + Wide range of signal gain adjustment
Very easy setup requiring no PC but just a
small screwdriver is enough output of the DTT Proces- screwdriver
to do all that setting. A sor was completely free of
green LEDs mounted on the them. Only the two digital less than specified (30 dB) the passband is very flat – – none
Jacek Pawlowski
TELE-satellite
Test Center
top of each module signals channels were left. We ad- but still quite a lot. The ad- another desired feature of a Poland
which one is turned on. justed the output of every ditional output boost that good filter.
Except for that, every unit channel to 70 dbµV without could be turned on with a We did not have an op- TECHNICAL
switch was 18.4 dB and 17.2 portunity to check the DAB DATA
has its own red knob for ad- any problem.
dB respectively. Almost ex- band but after such impres- Manufacturer Global Invacom Ltd., Great Britain
justing channel gain. The But that’s not all. The car-
actly in line with the speci- sive results with TV chan- Web www.gloablinvacom.com
nominal adjustment range rier-to-noise (C/N) param-
is 30 dB. There is also one eter measured at the output fication (20 dB). Of course, nels, we have no doubt that E-mail sales@globalinvacom.com
slide switch enabling you to was better than that at the we had absolutely perfect also this band is processed Phone +44-1621-743440
additionally boost the out- input by 12 dB! For example video when we connected a equally well. For DAB, Glo- Fax +44-1621-743676
put by about 20 dB (18 dB in for E45 channel, it rose from DTT receiver to the proces- balInvacom uses a Low Pass Model FibreIRS DTT Processor
the specs). It adds this extra 31.1 dB to 43.7 dB. We were sor output. Filter. Function Filtering and amplifying terrestrial signal
gain to all passed through really astonished because Finally, we fed the pro- To sum it up – the proces- DVB-T
4 channels. It may be very we had not expected such cessor with a white noise sor delivers what its specifi- Frequency range 470-862 MHz
useful when you deal with significant improvement in generator signal to exam- cation promises. The output Number of channels 6 (expandable to 9)
very extended or complex signal quality. ine the frequency response. signal is exceptionally clean Broadcast standard 8 MHz
cable networks in which you We checked the gain ad- As our screen shots clearly and its C/N improves more Gain 20 dB
expect significant attenua- justment range for every show, the performance of than anybody could expect. Channel flatness < 2.5 dB
tion. channel. We got 26 dB ad- the filters was awesome. We can heartily recommend Adjacent channel rejection > 45 dB
For best performance, the justment range for E41 and We sometimes use the term using GlobalInvacom Fi- DAB
input signal should be above 24.5 dB for E45. A little “brick wall’ for a filter with breIRS DTT Processor not Frequency range 217-230 MHz
extremely steep roll-offs. only for any fiber optic sys- Insertion loss < 2 dB
1. The original input signal picked up by a terrestrial antenna. That’s the term you can tem but also for the usual DC power
There are 2 DVB-T signals at 634 and 666 MHz (channel 41 and 45) certainly use for GlobalIn- coax cable distribution net- Input voltage 20 V
and a lot of unwanted noise.
vacom’s FibreIRS DTT Pro- works. We are sure that the Current consumption 1A
2. After passing FibreIRS DTT Processor, only the desired DVB-T
signals remain. cessor. Its SAW filters do a end users will be completely Physical
3. A test with a white noise generator proves excellent adjacent very good job. You can see satisfied with the quality of Size 182 x 205 x 122 mm
channels rejection. it in the other screen shots terrestrial signals delivered Weight 3.7 kg
4.Sharp roll-off and flat pass band - splendid frequency characteri-
stics of one of the FibreIRS DTT Processor channel filters. shown in this report. Also to their outlets. Operating temperature 0 to +50º C
20 TELE-satellite International — The World‘s Largest Digital TV Trade Magazine — 06-07-08/2012 — www.TELE-satellite.com www.TELE-satellite.com — 06-07-08/2012 — TELE-satellite International — 全球发行量最大的数字电视杂志 21