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10.11.2 Frequency
10.11.3 RBW
The Spectrum mode function is divided into five sub windows:
• Frequency
• Resolution Bandwidth
• Level
• Marker
• Wide Mode
The fifth button is used to change the spectrum view to wide screen mode,
as shown in the picture 4-1, and with the Esc button the original view can be
restored.
Always use Esc button to return to the previous view/condition.
Allows the User to set the tuning frequency and also the Span.
The Center frequency of the Spectrum window can be directly edited into the
window or set by the arrow buttons or by the rotary knob, which frequency
steps are set under the Manual mode.
Depressing the Center button the figures 0, 1, 2, 3, and 4 are selectable;
with the right arrow key it is possible to select the figures from 5 to 9, and
pressing again the right arrow key the units kHz, MHz and GHz becomes
accessible, as well as the decimal dot and the Back Space. The left arrow
key can be used as well to move back and forth from one screen to the
other. Pressing 0 as the first figure the decimal dot appears automatically.
To set a given frequency it is therefore enough to edit the value with the soft
keys and the left an right arrows, confirming the selections entering the units
value (kHz, MHz or GHz).
The figures entered appear in a small window just below the graph and the
default unit is MHz, so 100 kHz = 0,1 MHz; 10 kHz = 0,01 MHz;
1 kHz = 0,001 MHz and 100 Hz = 0,0001 MHz.
Using the Start and Stop buttons it is possible to select any start and stop
value in the frequency range 10 Hz to 3 GHz band.
Another method for setting the frequency is to enter the Center frequency
and the appropriate Span.
In this mode of operation the frequency step (spectrum resolution) is set
automatically, therefore it cannot be changed manually.
The Resolution Bandwidth command is used to select the bandwidth of the
measuring filter. Seven bandwidth filters are available:
• 120 kHz CISPR 16 shaped at -6dB
•
3 kHz at -3dB
•
10 kHz at -3dB
•
30 kHz at -3dB
• 100 kHz at -3dB
• 300 kHz at -3dB
•
1 MHz at -3dB
The four larger filters are selectable from the first RBW screen, and pressing
the More RBW button it is possible to select all the other filters.
These filters are mathematically modeled using FIR (Finite Impulse
Response) technique and they are exactly as required by the standards.
More filters will be available as an option for specific applications, e.g. to
cover Military Standards requirements, etc.
PMM 9030 Frequency Extension
10-19
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