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2-29 Span Menu Spectrum Analyzer
2-58 PN: 10580-00349 Rev. M Spectrum Analyzer MG
2-29 Span Menu
Press the
Span
main menu key. This is equivalent to pressing the
Span
submenu key under
the Freq menu. The Span menu is used to set the frequency range over which the instrument
will sweep. The span can be set from 10 Hz to the maximum frequency of the instrument. The
Span can also be set to zero span.
Key Sequence:
Span
Span: This submenu key shows the current value for span in units
of GHz, MHz, kHz, or Hz. When the Span button is pressed, span becomes
the active parameter and may be changed. Use the keypad, the directional
arrow keys, or the rotary knob to increase or decrease the span frequency.
If the span is changed using the arrow keys, the span changes in a 1-2-5
sequence for each key press.
Span Up 1-2-5: This is a convenient way to quickly arrive at a wider span
value. The first time the submenu key is pressed, the span value increases to
the nearest even value that starts with 1, 2, or 5. For example, if the span is
1.8 MHz, then pressing the submenu key for the first time changes the span
to 2.0 MHz, and the next press takes the value to 5.0 MHz, and so on.
Span Down 1-2-5: This is a convenient way to narrow the frequency span.
The first time the submenu key is pressed, the span value decreases to the
nearest even value that starts with 1, 2, or 5. For example, if the span is
1.8 MHz, then pressing the submenu key for the first time changes the span
to 1.0 MHz, and the next press takes the value to 500 kHz, then 200 kHz, and
so on.
Full Span: Pressing this button sets the span to cover the entire tunable
spectrum of the instrument.
Zero Span: This submenu key sets zero span. In this mode, the display
shows amplitude changes at a single frequency. This function is frequently
used to allow the easy monitoring of power variations over time. For example,
if information about the amplitude of an 802.11a access point signal is
needed, then the access point frequency would be set as the center
frequency, resolution bandwidth would be set to a value wide enough to
encompass as much of the signal as possible, and the tester would walk
around the access point usable area while the instrument records the
amplitude using slow sweep.
Zero Span (Option 89): If Option 89 is installed on your instrument, press
the Zero Span key again (after the circle is red) to access the “Zero Span
IF BW Menu (Option 89)” on page 2-59 .
Last Span: This submenu key returns the span to the most recent span
value immediately before a change was made.
Back: Returns to the previous menu.
Figure 2-43. SPA Span Menu
Back
Span
Span
1.000 MHz
Span Up
1-2-5
Span Down
1-2-5
Full Span
Last Span
Zero Span
Zero Span