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TELE-satellite International — The World‘s Largest Digital TV Trade Magazine
— 04-05/2012
— www.TELE-satellite.com
you use your receiver’s actual
address!). Use ‘root’ without
a password to log in and once
you’re in the Linux shell type
in the command ‘passwd’.
Then you set the password
and key it in a second time to
make sure it is correct. From
now on that password is re-
quired for logging in as ‘root’
user.
Now the time has finally
come for checking out the new
blind scan functions. All fea-
tures are seamlessly incorpo-
rated in the firmware and can
be found in the signal search
menu – right where we would
have expected them. With the
new firmware the ‘Blind Scan’
option is added to the exist-
ing ‘Multisat’, ‘Single Tran-
sponder’ and ‘Single Satellite’
modes.
Blind scan with the AZBox
ME is a three-step affair:
First, the tuner scans the en-
tire frequency band for tran-
sponders. Next, reception pa-
rameters are determined for
each found frequency. In case
‘Network Scan’ is active all
associated transponder data
are extracted from the NIT
stream. The third step com-
prises the actual blind scan,
which means the individual
transponders are scanned for
channels.
In our test we were looking
for answers to the following
questions:
• How many channels are
found using blind scan as op-
posed to the pre-defined tran-
sponder list?
• How fast is blind scan?
• Are channels with low
symbol rates also found using
blind scan?
• Are the data of transpon-
ders found with blind scan
stored in the transponder list
so that those transponders
will also be found using regu-
lar search modes?
To find those answers we
started out with deleting all
channels transmitted from
HISPASAT 30.0W and initi-
ated a standard transpon-
5. The new blind scan functionality is seamlessly integrated in
the service scan menu.
6. Initialisation of the tuner.
7. Pass 1: The tuner searches for active frequencies.
8. Pass 2: All found frequencies are analysed to determine
the correct Symbol Rate and to obtain other transponders
broadcasted in the NIT.
der search (‘Single Satellite’
mode) with active network
scan. In general, providers
take advantage of ‘their’ tran-
sponders to transmit informa-
tion on other transponders
they also use, so that users
can be sure their receivers
find all channels of individual
providers, no matter over how
many transponders they are
spread. More often than not,
pre-defined transponder lists
are not fully up-to-date and
therefore it makes sense to
always use the benefits of net-
work mode to make sure your
receiver can find all available
channels. The search on HIS-
PASAT 30.0W took some 24
minutes and yielded a total of
548 channels.
We then proceeded with
performing the same search
on the same satellite using
the newly added blind scan
function. Once again, we
made sure ‘Network Scan’
was turned on. This time the
search only lasted 18 minutes
and resulted in 613 identified
channels. Needless to say, we
were rather impressed with
the capabilities of the AZBox
ME’s blind scan mode.
We gave the channel list
a quick look and stumbled
across three channels that
might be of particular interest
to satellite DXers. (table 1)
Many tuners struggle with
symbol rates of around 2000
Kbit/s and if that happens
these channels are either not
found at all in a search or not
demodulated correctly. We
were all the more surprised
to find out that the AZBox ME
seems to be in a league of its
own as far as low symbol rates
are concerned.
Excited by those promising
first results we hooked our 1m
offset antenna to the AZBox
and aligned it towards TEL-
STAR 12 (15.0W). This is a po-
sition that is not widely known
and used in Central Europe
as it only transmits few FTA
channels. Transponder 10 at
12608H seems to be the most
obvious choice – it is used by
Globecomm to broadcast BBC
Persian, among others.
To be frank, there is anoth-
er reason we chose TELSTAR
12 for a blind scan search: It
Tabel 1