TELE-audiovision - The World’s Largest Digital TV Trade Magazine - page 30

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TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine
— 03-04/2014
14. Measuring analogue CATV channels
is very simple and quick. Just select the
required frequency and off you go. All
relevant information is displayed in one
single screen and PASS/WARNING/FAIL
icons show immediately if the channel to
noise ratio, video to audio ratio and signal
level are adequate.
15. If only one measuring parameter is
important it can be displayed exclusively in
a larg font.
16. One of the special features of the R&S
EFL210 is its capability of mixing different
information into one single screen. For
analogue channels visualizing the image
is often not enough. Being able to evaluate
the line signal allows to check for example
if the sync signals are within conformity.
17. This oscilloscope functionality can be
displayed individually. It is possible to
select the line to be analyzed and to zoom
in.
18. Zooming in reveals some noise within
the line blanking interval. Despite having
an acceptable picture quality, this shows a
potential problem.
19. A different visualization mode shows
the demodulated image next to the
spectrum view of the current transponder.
The relevant measurements are displayed
as well.
20. The tuner and demodulator are of the
finest quality and despite the considerably
weak signal a good image is rendered. This
only shows how important it is to rely on
the measurements and explains why you
can never use a normal receiver or TV to
evaluate a CATV signal.
21. One interesting measurement is the
channel/noise ratio of a selected video line.
Instead of measuring against an average
of all lines you can select a specific line,
against which you measure the ratio to
the noise level. This is very handy if you
are working with test pictures, where the
desired pattern occupies only part of the
image.
22. You can specify the level thresholds.
Once the set level is reached the
instrument stops the search. The search
function can be done in both directions
and the spectrum updates in real-time,
following the frequency.
23. Once a channel is found with at least
the specified signal level the search stops
and immediately the measurements are
presented.
24. To make the channel tuning easier it is
possible to select from a list of predefined
channel plans. I have created my own
channel plan, covering all analogue
channels of my cable operator using the
R&S EFL Suite on the PC.
25. Configuring the audio.
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