Spectrum Monitoring And Interference Hunting - Keysight HSA N9342C Demonstration Manual

17 | Keysight | N9342C/N9343C/N9344C HSA Handheld Spectrum Analyzer - Demonstration Guide
Demonstration 6

Spectrum monitoring and interference hunting

Option SIM provides a spectrogram that provides a three-dimensional
display of the spectrum with power over frequency and time. This
feature helps find intermittent interference signals, as well as locate
and identify unwanted signals that cause dropped calls and poor
quality service in communications systems. The X-axis represents
frequency as in a normal spectrum display, but amplitude is
represented by color: red for a strong signal and blue for noise floor.
The Y-axis represents time, with the trace from the newest sweep
displayed at the bottom of the screen. Earlier traces move up towards
the top of the screen with each new sweep. Two coupled markers allow
you to place a marker on any trace in the spectrogram and view the
normal spectrum for the time of that sweep. The time interval between
sweeps can be adjusted, and up to 1,500 traces can be displayed and
saved.
In this demonstration, the N9311X-500 whip antenna is used to receive
over the air GSM uplink signal. For interference hunting application, a
directional antenna like the N9311X-504 is recommended.
Instructions for HSA
Connect the N9311X-500 whip antenna to the N934xC HSA RF input connector
Set the center frequency and span
Set Y scale/div and On Hi- Sensitivity to On
Note: If Hi-Sensitivity is On, parameters below can be set automatically:
– Reference level -50 dBm
– Attenuator 0 dB
– Preamp On
Turn on spectrum monitor (N934xC-SIM option needed)
Instructions for HSA
Set the update interval time between two frames
Turn on Marker 1 and Marker 2
(Note: Marker 1 is on by default)
Move marker to the location by setting frequency or time
Turn on file logging
Note: There are manual and automatic methods to save data, and the filename's
format is <Prefix>_<Index>_HHMMSS
– <Prefix> is N934X by default, you can edit the <Prefix> by pressing {File Path},
{Setup}, {Prefix Edit}, input the name in the "Save as" dialog box, [Enter]
– <Index> is 0, 1, 2, 3....
– HHMMSS is the time to start saving
Manual save data
Note: To stop saving press {Stop Save}
Automatic save data
Note: To stop saving pressing {Return}, {Stop Save}
Recall the saved spectrogram file and playback (Figure 20)
Figure 20. Spectrum
Keystrokes for HSA
[FREQ], {Center Freq}, [925], {MHz}, [Span], [70], {MHz}
[Amptd], {Scale/Div},
{5/DIV}, {More 1 of 2},
{Hi-Sensitive (On)}
[Meas], {Spectrum Monitor}
Keystrokes for HSA
{Update Int. (On)}, rotating knob or pressing numeric keypads to set
the update interval time
[MARKER], {Marker (2)}, {State (On)}
{Frequency} or {Time}, rotating knob or pressing numeric keypads to
change the marker's location as desired
[Meas], {File Logging}
{Start Save}
{Timed Setting}, {Start Date}, date format is YYMMDD, such as:
[20100712], [Enter], {Start time}, time format is HHMMSS, such
as: [145945], [Enter], {Stop date}, [20100712], [Enter], {Stop time},
[133000], [Enter], {Time Save (On)}
[Shift], [File], rotating knob and highlight the spectrogram file, {Re-
call}, {Spctrg View}, {Playback}, {Play}