Keysight N9927-90001 User’s Guide                                                            213
RTSA (Real-Time Spectrum Analyzer) Mode—Option 350 (CPU2 Only)
RTSA Mode Settings
— Then choose from the following:
— Auto
 Res BW is coupled to the frequency span. As the frequency 
span is narrowed, the Res BW is also narrowed providing increased 
ability to resolve signals.  
To change this setting from Man to Auto, press Res BW twice.
— Man
 Enter a Res BW value using the numeric keypad, the   
arrows, or the rotary knob. Then press a multiplier if necessary or 
press Enter
The current Res BW setting is shown at the bottom of the screen. 
#Res BW x.xx XHz (#) means manual setting.
This setting could impact the accuracy of the measurement. See Specifications 
in Appendix B. 
Triggering
External, Video, and RF Burst triggering enable you to initiate an RTSA mode 
sweep using an external event such as a signal burst. 
Trigger Type
—Press Sweep 3
—Then Trigger Settings
—Then Trig Type
— Then choose from the following:
— Free Run
 Triggering is provided by the FieldFox internal circuitry. A new 
sweep begins when the previous sweep ends. 
— External
 A sweep is triggered on an external TTL signal at the Ref In/Trig In 
connector on the FieldFox top panel. Choose to trigger on the rising slope 
at about 1.7 V or on the falling slope at about 1.0 V using the Trigger Slope 
setting (below). 
The following two selections are similar in that they both trigger a sweep from 
a signal at the SA RF Input connector. Experiment with both selections to find 
the best trigger type for your application.
Triggering only applies to Density Spectrum and Real-Time Spectrum.