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TELE-satellite International — The World‘s Largest Digital TV Trade Magazine
— 1 -12/2012
—
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tuned to. It could not be sim-
pler!
The AE120 has selectable
wavelengths. As you could
expect, there are the com-
mon 1310 nm, 1490 nm and
1550
nm bands. But not only.
One can order additional,
user defined wavelengths.
Our test unit had four addi-
tional bands: 850 nm, 980
nm, 1300 nm and 1610 nm –
so seven in total. The λ but-
ton is used to cycle through
different wavelengths. On
power up, the smallest one
is selected (850 nm in our
case). You should switch to
the correct wavelength in or-
der to get the correct result.
You can easily guess the
function of the other but-
tons. The dBm/W button is
used to cycle the units of
the measured power. The
REF button is used to store
the current measurement
result as the reference level
to which you will be able to
compare the next measure-
ment – most likely - in the
other nodes of the network.
To store the reference level
you press and hold a but-
ton for a longer while. An-
other short press - and you
are back in the normal mode
when you measure the pre-
sent value.
Having stored a result as
the reference, you can press
the dB button to express the
current measurement with
respect to the stored value in
decibels. For example, if you
had measured in one node
a value of +3.66 dBm and
stored it as a reference and
then moved to another node
of the network and meas-
ured -3.38 dBm, pressing
the REF button would show
you -7.04 dB. The meaning
of this would be that at the
second node the signal was
7.04
dB weaker than in our
reference point. In this way,
we can conveniently check if
the optical splitters located
between the two nodes do
not introduce too much at-
tenuation.
The function of the two
remaining button is self-ex-
planatory: one turns on and
off the back-light of the dis-
play and the other is just the
power on/off switch. As you
can see, once you get famil-
iar with this meter, you will
never forget how to use it -
it is so straightforward and
logical.
In order to test the AE120
meter, we used an optical
transmitter converting a
DVB-T signal into an optical
one. We compared the me-
ter to another similar tool
dedicated for the installers.
(
graph 1.)
As you can see in the at-
tached graph, the results
of both meters were quite
similar. However, when we
attenuated the signal, AE120
was still able to measure it
(-19.97
dBm) while its com-