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Q u i c k i n t r o d u c t i o n
Q u i c k i n t r o d u c t i o n
4 Quick introduction
The following chapters are intended to introduce you to the
most important functions and settings of your new HAMEG HMS
spectrum analyzer (here: HMS3010) in order to enable you to
immediately use it. You find more detailled explanations in the
chapters following these ones.
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4
5
8
10
12
13
6
7
9
A
Fig. 4.1: Area A of the control panel
4.1
How to measure a sine wave signal
The fundamental measurement with a spectrum analyzer is
the measurement of the level and the associated frequency
of a sine wave signal. The following measurement example
demonstrates the steps to be taken for the settings which
allow to effectively perform this measurement with the HMS
series. The signal source is a HF synthesizer, e.g. the HM8135.
Connect the HF output of the synthesizer to the HF input of the
spectrum analyzer.
Settings on the synthesizer:
–
Frequency 100 MHz
–
Level –10 dBm
Press the AUTO TUNE key
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to scan the whole measuring range in order to find the highest
signal peak and to display it at the screen center together with
the proper RBW and span settings. This procedure may take
several seconds.
Fig. 4.2: Display with the AUTO TUNE function
4.2
Level measurement
In order to now perform the previouly automatically taken steps
manually, press the key PRESET
to its initial settings.
42
Subject to change without notice
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17
15
16
18
in order to cause the instrument
which resets the instrument
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The analyzer displays the frequency spectrum of its full frequency
range from 100 kHz to 1.6 GHz resp. 3 GHz. At 100 MHz the genera-
tor signal will be discernible as a line. Harmonics of the oscillator
are also displayed at multiples of 100 MHz (not visible here). In
order to analyze the generator signal further, use the frequency
settings menu (key FREQ
) to set the start frequency to 50 MHz
6
and the stop frequency to 250 MHz. The spectrum analyzer now
displays the signal with a higher resolution.
In order to determine the level of the signal, the HMS series
offers up to 8 markers. The marker is always attached to the
measuring curve. The instrument indicates the level and the
frequency at the relevant position on the screen.
Press the key MARKER
to enter the marker settings menu.
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Marker [1] will be activated by the soft key DISPLAY, it will be
automatically positioned to the center frequency of the actual
curve. The marker frequency is indicated by a cross resp. arrow
symbol (next to the activated marker). The spectrum analyzer
displays the level and the frequency of the marker position
numerically at the top of the screen.
Now move the marker [1] to the displayed level at 100 MHz by
pressing the soft key POSITION and, after selecting the marker
(the marker indication will turn to orange), use the knob to
move it to the left; you may also enter the desired frequency of
100 MHz directly via the keyboard.
Fig. 4.3: Level measurement with marker
4.3
Measurement of the harmonics of a sine wave
signal
Due to the property of a spectrum analyzer to resolve different
signals in the frequency range, it is well suited to measure
harmonics or the distance between harmonics and the funda-
mental. The HMS offers extended marker functions which allow
to arrive at a result after just a few key pressures.
Due to the previous settings in chapter 4.2, the first marker is al-
ready located on the fundamental which should stand clearly out
of the noise floor in the lefthand screen area. The marker should
also display the selected level of –10 dBm in the upper screen
area. The first harmonic of the sine wave should now appear at
200 MHz. Depending on the purity of the signal this harmonic
may be well or hardly visible with the presently active settings.
In order to measure the distance of the first harmonic to the
fundamental proceed as follows:
Press the soft key MARKER and move the knob by one detent
position to the right in order to select a second marker (M2).
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