TELE-audiovision - The World’s Largest Digital TV Trade Magazine - page 80

TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine
— 01-02/2014
Filter for SCR Distribution System
single cable commands that
refer to the correct carrier
So, for example, if the
end user accidentally re-
programs his receiver to
another carrier frequency
which is assigned not to him
but to his neighbor, the SMA
8 F will stop the improper
commands generated by
the receiver. In this way, it
will block them from enter-
ing the line and interfering
with another user’s recep-
tion. The same holds true
if the end user reconfigures
his receiver to a universal
LNB rather than a single
cable signal. Of course, the
user who tampered with
the settings of his receiv-
ers will loose the reception
but not one of his neighbors
will suffer. And it will be
very easy for the installer to
fix the situation, as he can
easily check the SMA 8 Fil-
ter for the assigned carrier
frequency number and then
adjust the SCR receiver ac-
Enables the creation of an error-tolerant
SCR distribution system
Installing a reliable and error-free
SCR distribution system
A Single Cable Router dis-
tribution system can feed up
to 8 SCR satellite receivers,
giving each of the receiv-
ers the full satellite IF signal
with just one single Quattro
LNB. How is it done? Switch-
ing between the 4 levels
(Vertical and Horizontal,
Low and High Band) is done
by assigning each of the SCR
receivers their unique car-
rier frequency to transmit
the switching signals back to
the LNB.
So far so good, the system
works perfectly as long as
each SCR receiver is indeed
using its assigned carrier
frequency. But then some-
one tampers with his receiv-
er, or buys a new receiver
without contacting the sys-
tem’s administrator, or does
a re-set of his box. Eventu-
ally two SCR receivers in the
system might end up using
the same carrier frequency.
The system becomes unsta-
ble and the installer is called
in to find what’s wrong. In
order to locate the source of
the mixup checking all SCR
receivers is required, but
how to get access to the re-
ceivers, when people are not
at home, or on holiday or the
receiver can’t be accessed
for any other reason?
SPAUN invented a very
easy solution to this prob-
lem: the SMA 8 F filter. This
is a small box to be inserted
between the subscriber’s
socket and the IF input con-
nector of the SCR receiver.
It does not filter the signal
spectrum but prevents a re-
ceiver from interfering with
other receivers connected
to the same single cable
line. The filter has a 8 pole
DIP-switch, which needs to
be set to the carrier’s fre-
quency number of the corre-
sponding SCR receiver con-
nected to this outlet. Now
the filter passes only those
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