TELE-audiovision - The World’s Largest Digital TV Trade Magazine - page 112

TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine
— 1 -12/2013
DAB+ and FM yet with the
matching drivers you can
also use USB DVB-T receiv-
ers with Software Defined
Radio (SDR); using special
SDR software like SDR# you
get a real scanner radio with
which for example you could
tune into air traffic control.
The problem though is
the built-in tuner in the
USB DVB-T receiver. Differ-
ent chips are used here, for
example, the FC0012 and
FC0013 models. One of the
USB receivers in our test
center has the FC0012 tuner.
Unfortunately, these tun-
ers are limited to the 50 to
950 MHz frequency range
but it‘s the 117 to 137 MHz
aircraft band that‘s especial-
ly interesting. Our test cen-
ter was thus outfitted with a
proper antenna and using an
Icom R3 we could listen in to
the aircraft band.
Since there aren‘t continu-
ous transmissions on these
frequencies and since I want-
ed to more closely analyze
the sensitivity and reception
capabilities of the USB re-
ceiver, it was once again time
to put the Handheld Satcom
Test Source to work.
The test setup was ex-
tremely simple: the USB
DVB-T receiver was connect-
ed to a PC and installed with
the special SDR drivers that
can be found in the Inter-
net under the name ”Zadig“.
This freely available SDR#
software was automatically
recognized by the USB re-
ceiver with its RT-L2832U
chips and just like that the
signal can be displayed on
the PC as a spectrum. De-
modulation takes place in
the modulations typical for
a scanner radio: AM, FM, CW
etc., whereby the bandwidth
can be individually set.
On the Handheld Satcom
Test Source a variety of fre-
quencies were tried between
50 and 180 MHz with empha-
sis on frequencies from 117
to 137 MHz.
The results can be seen in
the pictures and vary from
spectacular to disappointing.
The resolution of the signal
displayed by the Handheld
Satcom Test Source was ex-
cellent. In the aircraft fre-
quency band it appeared
that the USB DVB-T receiv-
er would be able to provide
a usable signal so the next
step was to connect it to
the outdoor antenna. Sure
enough, after only a few
minutes an aircraft could be
heard making an approach
to an airport.
The disappointment came
about because the USB DVB-
T receiver in no way could
receive this popular fre-
quency band correctly. The
signal from the Handheld
1...,102,103,104,105,106,107,108,109,110,111 113,114,115,116,117,118,119,120,121,122,...260
Powered by FlippingBook