Page 68 - TELE-audiovision - The World’s Largest Digital TV Trade Magazine

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03-04/2013
TELE-audiovision.com/13/03/antiference
68 TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine — 03-04/2013 — TELE-audiovision.com
A Professional
DTT Headend
TEST REPORT DTT Headend
Frequency spectrum is a
valuable asset. There are
various international and
national bodies who grant
parts of the spectrum for
particular services. Digital
television is just one of such
services and it has to coex-
ist with the others like the
new LTE Internet communi-
cation, or digital radio DAB
or the old FM radio. Such
coexisting services, even if
they occupy different but
neighboring frequencies,
could negatively interact
with one another.
In a cable system supply-
ing terrestrial TV signals to
every apartment in a large
block, apart from install-
ing cables and splitters, we
need to significantly ampli-
fy the signal received from
the antennas on the roof.
Should we do that with a
simple wideband amplifier,
the signal reaching many
apartments would be very
noisy. That is because there
would be inevitable inter-
modulation in a high gain
amplifier and many unde-
sired spurious signals would
be created.
No matter if this is the
old analog technology or
the modern contemporary
digital communication, the
solution is always the same:
block unwanted interfer-
ence signals and only then
process what is left – your
desired signal. And such
anti-interference function
is the main feature of the
new headend offered by
Antiference in the UK. It is
designed to receive up to
ten different DTT channels,
filter them from unwanted
“neighbors”, amplify and
then move them to other
frequencies if desired. So, it
is not for converting terres-
trial or satellite TV to cable
TV. This headend by Antifer-
ence is a chain link of a ter-
restrial distribution system.
If you add a suitable trans-
mitter and antenna at the
output of this headend, you
could convert it to a TV re-
peater retransmitting DTT
channels on different fre-
quencies.
Oh, and we are intention-
ally using the term DTT
here, because this headend
is designed for any digital
channel with 7 or 8 MHz
bandwidth and this means
DVB-T/T2 as well as the
Chinese DTMB standard.
Other DTT modes like ATSC
or ISDB-T are based on 6
MHz channel bandwidth and
would not be suited for the
Kingray headend by Antifer-
ence.
Antiference provided us
with the KR-110 headend
rack, the KLA-110 Launch
Amplifier/Power Supply
and three KCC-110 Chan-
nel Convertor/Processor
units. Workmanship of all
the components left abso-
lutely nothing to be desired.
Everything looked perfectly
finished off. Antiference
even attached a foiled paper
with a channel plan listing
channel numbers and cor-
responding frequencies for
analog and digital channels.
This is a nice accessory and
it proves that the manufac-
turer really cares about the
customer. The accompany-
TELE-satellite editor Jacek
Pawlowski testing the Kingray
headend by Antiference. In his
setup he connected the system
to a live DTT signals and
measured the output results.
KLA-110 Launch Amplifier &
KCC-110 Channel Convertor/Processor
Professional handling
of DTT signals