Pagina 21 - TELE-satellite-1207

Versione HTML di base

Jacek Pawlowski
Test Center
Global Invacom Ltd., Great Britain
FibreIRS DTT Processor
Filtering and amplifying terrestrial signal
Frequency range
470-862 MHz
Number of channels
6 (expandable to 9)
Broadcast standard
8 MHz
20 dB
Channel flatness
< 2.5 dB
Adjacent channel rejection
> 45 dB
Frequency range
217-230 MHz
Insertion loss
< 2 dB
DC power
Input voltage
20 V
Current consumption
1 A
182 x 205 x 122 mm
3.7 kg
Operating temperature
0 to +50º C
21 —
06-07-08/2012 —
TELE-satellite International —
Very good adjacent channel separation
Flat pass band
Wide range of signal gain adjustment
Very easy setup requiring no PC but just a
Expert Opinion
less than specified (30 dB)
but still quite a lot. The ad-
ditional output boost that
could be turned on with a
switch was 18.4 dB and 17.2
dB respectively. Almost ex-
actly in line with the speci-
fication (20 dB). Of course,
we had absolutely perfect
video when we connected a
DTT receiver to the proces-
sor output.
Finally, we fed the pro-
cessor with a white noise
generator signal to exam-
ine the frequency response.
As our screen shots clearly
show, the performance of
the filters was awesome.
We sometimes use the term
“brick wall’ for a filter with
extremely steep roll-offs.
That’s the term you can
certainly use for GlobalIn-
vacom’s FibreIRS DTT Pro-
cessor. Its SAW filters do a
very good job. You can see
it in the other screen shots
shown in this report. Also
the passband is very flat –
another desired feature of a
good filter.
We did not have an op-
portunity to check the DAB
band but after such impres-
sive results with TV chan-
nels, we have no doubt that
also this band is processed
equally well. For DAB, Glo-
balInvacom uses a Low Pass
To sum it up – the proces-
sor delivers what its specifi-
cation promises. The output
signal is exceptionally clean
and its C/N improves more
than anybody could expect.
We can heartily recommend
using GlobalInvacom Fi-
breIRS DTT Processor not
only for any fiber optic sys-
tem but also for the usual
coax cable distribution net-
works. We are sure that the
end users will be completely
satisfied with the quality of
terrestrial signals delivered
to their outlets.
TELE-satellite Test Editor Jacek Pawlowski at
work. The FibreIRS DTT Processor is connected
to a professional signal anaylzer. the analyzer‘s
video output is fed into the laptop to generate the
screenshots for this report.