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HISTORY
TELE-satellite Archives
RO.VE.R. SDA-5 Digisky
Although it comes with a very long name, this new
measuring tool is one of the smallest professional
analyzers we have seen so far. It has been
designed for measuring analogue and digital
signals. It is light-weighted, only 1.3kg, and is very
small. It comes in a yellow carrying case, which
also has room for adapters and other accessories.
A shoulder strap makes it easy to carry. A
first look at this device will show you that is must
be easy to operate. It doesn’t feature many buttons,
which most of the times are hard to reach.
No just a few buttons, seven to be precise, will
do the trick. And that is just what you need when
you are high up on the roof, in combination with
a two-line LC display (16 characters each.)
The SDA-5 from Digisky is designed for measuring
satellite signals only, and can therefore
only handle signals between 950 and
2150MHz. This way you won’t pay for things
you don’t need. For terrestrial signals, RO.VE.
R offers the TDA-4, which looks the same.
For analogue signals, the measuring takes place
in dBµV or dBm together with a C/N figure.
Additionally, you can test external devices
like LNBs and multiswitches. If problems with
cross-polarisation occur, in most cases this
is caused by miss-configuration caused by
not using proper measuring equipment.
Use the SDA-5 to reach a perfect offset
for your LNB. For analogue channels, a
quick glimpse of the screen will do a lot.
But for digital signals this is impossible.
There is only one way to measure the quality of
digital signals: facts and numbers. Good measuring
with good measuring equipment is the answer.
A simple signal strength measuring tool won’t
help. It is the very strength that doesn’t say much
about the digital quality of it. For digital signals,
the quality is measured in BER (Bit Error Rate),
before and after Viterbi. You will need a tool like the
SDA-5 from Digisky for real professional installations
and measuring. A perfect BER depends
on the size of the dish, LNB and cable lengths
and quality of the multiswitches in between. This
Digisky will continuously show this figure.
DVBeam IP Card
Teleworking has been some kind of utopia for
many years. Geographically separated offices
only could communicate using expensive
data lines, using low data rates and being
only suitable for slow traffic. For larger files
good old snail mail was just the answer. And
although video conferences has been around
for many years now, most of the time it is based
on ISDN lines, with a maximum of 128Kb (at
double rate.) For data-intensive requirements,
such as for instance an advertising agency
wanting to show their latest commercial, it
is far too slow. And another problem is the
absolute lack of compatibility between the
different platforms around. The introduction
of MPEG2 meant a full globally compatible
digital platform for transferring satellite television
and radio. But the DVB standard can also
integrate packages of business information.
This way it created a cost-effective way to
have permanent on-line connections to
all branch offices. Not only data, but with
video and audio as well. Now it is possible
to show that new commercial without
visible or audible quality loss.
For training purposes, you can think of the
possibilities regarding remote education. You
can cut the cost for travelling and hotels, and
organising training by satellite is done much
faster and easier. Back channels are of course
possible although they still use landlines. In
future, this will be also done via satellite; offering
higher speeds and a full interactive solution.
128 TELE-satellite & Broadband — 06-07/2009 — www.TELE-satellite.com
Nowadays, Internet connections are a must
for every company. Transferring data between
two branch offices using an ISDN connection
to the Internet, will take a lot of time
when larger files are involved. For instance,
a 120Mb file will take up to several hours to
transfer. Using a satellite connection this can
be reduced to 36 minutes. Almost all satellite
operators offer the same platform, but
there is still a big need on PC hard/software.
Enter the DVBeam IP-Card from Sican. It
integrates all we have discussed so far:
Business-TV, Internet on satellite, satellite
radio and TV (MPEG2, European DVB). You
can use it as a simple MPEG-2 receiver, but it
can do much more than just that: it can turn
your PC into a real multimedia terminal.
At TSI, we recently received a pre-production
sample. Although we expected a lot of trouble
installing this test board, we were really surprised
by the ease of installation. As long as
you use Windows NT4, Windows 95 or Windows
98 there is no real problem. For Windows NT4
you need to do the installation yourself, on Windows
95 and 98 the system will recognise the
card and install all drivers and software needed.
The minimum system requirement is a PC with
at least 90MHz. But Sican suggest a better
performance with at least a 166MHz, and
this is true. The same goes for the minimum
memory requirements: 16Mb, but in practice
just ensure that your system has at least 32Mb
of RAM installed. The VGA card should be
of the SVGA type and should use DirectX.