Promax MC-377+, Инструкция по эксплуатации

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INSTRUCTION MANUAL MC-377+.
Page 21
May 2001
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4.2.4 Spectrum Analyser operating mode
The Spectrum Analyser operating mode enables you to be easily and quickly
informed on the signals present in each band of the zone or region you are currently in.
To select this operating mode, extract the MON./SPEC key [5] and an image will appear
on the monitor similar to the one shown in the following figure.
Figure 5.- Spectrum analyser mode, MAX mode.
The monitor will show a representation of the signals present in the band in function
of each frequency. The vertical axis corresponds to the frequency, the higher
frequencies being higher up on the screen and the lower ones further down. The
horizontal axis represents the level of the signals present in the band, the amplitude of
the lobes appearing on the screen represent the energy of the various signals present
in the band.
The bandwidth shown can correspond to the entire selected band (MAX mode) with
the SPAN/MAX key [6] released, or a smaller margin close to the current tuning
frequency (SPAN mode) with the SPAN/MAX key [6] pressed, then acting on the SPAN
control [23] in order to select the bandwidth to be shown, this may be chosen between
approximately 1/3 of the band (depending on the width of each band, to maintain the
power calibration) and a bandwidth of almost zero.
Having chosen a specific bandwidth, you may now vary the tuning with the TUNING
control [24] to gradually sweep the entire band of selected frequencies. The frequency
counter will show the tuned frequency.
In the complete band Spectrum Analyser mode (MAX, with the SPAN/MAX key [6]
released) a white horizontal line will appear on the monitor (tuning mark) showing the
tuning frequency (as can be seen in the previous figure). As you move across the
frequencies with the TUNING control [24] you will see the mark move across the entire
spectrum, allowing you to approximately pre-tune the frequency corresponding to the
lobe that the mark is on.