Aaronia SPECTRAN HF-2025, Manual

Page: 11 / 72

Directly beneath, a max. of 3 so-called “ Markers ” are being displayed. They
show the frequencies and levels of the strongest signal sources. In our example,
we got two
Markers : Marker 1 at 930MHz at -75dBm and Marker 2 at 950MHz
at -45dBm ( -45dBm also being the strongest signal and thus also shown on the
Main display ).
Beneath the Markers, a graphic with several “hills” is shown. It displays the level
distribution over the indicated frequency range. This is the so-called “ SPEC-
TRUM DISPLAY ”. The higher the “hills”, the stronger the signal at the respective
frequency. The aforementioned markers display the frequency and level at the
peaks of these “hills”.
The indicated frequencies allow exact mapping to origin and provider of the
transmitter. More details on this on page 44 ff., or in the frequency tables on
pages 64 ff.
5.2 The HOLD function
(The MODE status field displays “HOLD”)
As you have probably noticed, the display constantly
changes. This is completely normal, as the signal
strength of the high frequency radiation also
constantly
changes . This also depends on the alignment of the
antenna. Moving it only a few cm or a different bearing
can cause abrupt changes in readings. Just try it yourself
by aligning your antenna differently and checking out the
display.
Often, you will only want to evaluate the highest reading .
Though, as the display constantly changes, this proves
rather difficult. Thus, the so-called HOLD function is
used. To activate, press the Dot-key. “ HOLD ” appears in
the Mode status field . From now on, only the highest
value will be displayed. Also, the spectrum display does
not get erased anymore. The complete display now
appears “frozen”.
5.0 Your first measurements / Modes
11
Marker1
930MHz
-75dBm
Marker2
950MHz
-45dBm
Graphics display with
spectrum