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TELE-satellite International — The World‘s Largest Digital TV Trade Magazine
— 12-01/2012
— www.TELE-satellite.com
One Modulator for
Every Terrestrial Digital
TV Standard
The Gold Modulator
Digital TV has a number of
different standards. Most of
the terrestrial receivers that
we have introduced to you
here in the pages of TELE-
satellite receive signals in
the DVB standard, for ex-
ample, DVB-T (most often
used for TV transmissions in
standard definition) and the
newer DVB-T2 (mostly used
for high resolution signals).
For those receivers used
with cable TV networks, it’s
mostly DVB-C while receiv-
ers in the ISDB-T standard
are used in South America.
TELE-satellite test report-
ers can be found all over the
world and therefore have
direct access to their corre-
sponding signal standards.
But the same can’t be said
for receiver manufacturers: a
receiver production line sim-
ply can’t be moved from one
location to another for the
purpose of receiving live TV
signals in other standards.
Obviously, it would be far
better to bring the neces-
sary signals to the manu-
facturer. DekTec, a com-
pany located in Holland, has
developed a multi-standard
modulator just for this type
of application. It’s ideally
suited to test terrestrial
receivers in different TV
standards and to take these
digital TV signals and make
them available in the VHF/
UHF range.
All of the DekTec’s modu-
lator hardware is enclosed
in an unremarkable, silver-
gray aluminum box that is
123 x 62 x 22mm in size. It
comes with a single USB 2.0
connector as well as the RF
signal output on both ends
of the box.
If you’re all scratching
your heads now trying to
figure out where the in-
put signal comes from and
how the box gets its power,
DekTec has found a rather
interesting solution: the
DekTec DTU-215 is designed
to be used with any stan-
dard PC and thus gets its
power from thePC via the
USB 2.0 interface.
The little modulator box
doesn’t place too much of a
demand on the PC: an Intel
Pentium III processor with
1 GB of memory is enough
for almost all of the modula-
tor’s functions; in the case
of DVB-T2, a more powerful
processor would be needed,
for example, an Intel Core 2
Duo.
All of the required drivers
and the necessary software
are supplied by DekTec on
a USB stick. This USB stick
not only contains the soft-
ware for the DTU-215, but
it also has DekTec’s en-
tire software palette. This
means the user has to
search through all the files
on the USB stick to find the
matching software for the
DTU-215.
Overall, the workmanship
and packaging of the modu-
lator left us with a very good
impression; clearly, this is a
high-end product for use by
professionals.
We referred to the instal-
lation manual included by
the manufacturer regard-
ing the integration of the
required drivers in the op-
erating system (Windows
XP/2003/Vista/2008
and
Windows 7 are supported).
This all functioned very eas-
ily with a double-click on the
installation assistant. The
Stream Player Software, the
modulator’s actual control
center, was just as quickly
installed and set up only
after we found it hidden
behind a DTC-300 labelled
folder on the included USB
stick.
Once all of the software
needs were taken care of,
we connected the modula-
tor to our PC via the USB 2.0
port. Windows instantly rec-
ognized the new hardware
and set it up in just a few
seconds.
Before we can start test-
ing this modulator, a few
basic settings have to be
taken care of first. This in-
cludes the modulation mode
as well as the desired output
frequency. The modulations
are listed in Table 1.
The user can select an
output frequency between
47 and 1000 MHZ in the
VHF and UHF bands with
a bandwidth from 2.7 to 8
MHz. The modulators sig-
nal output level for QAM is
between -46 and -15 dBm;
with OFDM it lies between
-49 and -18 dBm. The mod-
ulator draws roughly 500mA
at 5V; this can be obtained
from a USB 2.0 interface so
TEST REPORT
Digital TV Modulator