Performing a Basic Interference ID Measurement


Step
 		Notes
1
 		Select Spectrum Analyzer.
  • Mode
  1. [Spectrum Analyzer/Tools]
  2. [Spectrum Analyzer]

2
 		Enter the channel standard.
  1. [Chan Std]
  2. Select the standard using the up and down arrow buttons.
  3. [Select]
  4. On [Units] select Chan.
Each time you press the [Units] menu key, the selected option changes.
3
 		Enter the channel number.
  1. [Channel]
  2. Enter the channel number using the numeric keypad.
  3. Select [Fwd] or [Rev].

4
 		Set the span.
  1. [Span]
  2. Enter the frequency using the numeric keypad.
  3. [Hz], [kHz], [MHz], or [GHz]

5
 		Connect to the base station.
6
 		For an Over The Air measurement, connect an antenna and an external filter to the RF input.
 		The external filter is necessary to eliminate out-of-band signals that would otherwise reduce the dynamic range of measurements in the band of interest. The effect of the out-of-band signals is to raise the noise floor, possibly hiding some or all of the signal of interest. However, the external filter is optional in this set up:
  • If you want to limit your search to a specific band of interest, then you should use the external filter.
  • If you want to search beyond a specific band, then you can leave the filter off.
7
 		Set the level to Autoscale.
  1. [Level]
  2. [Autoscale]

8
 		Select the Interference ID Measurement.
  1. [Measurements]
  2. [Interference ID]
  3. On [Interference ID] select On.
A marker will appear on the trace at the left of the display. The Frequency and power level at the marker (Signal Pointer) is displayed in the data window below the trace display window. The type of signal that is causing the interference is also indicated.
9
 		You can set marker to a signal peak by:
  1. [Signal Pointer]
  2. Enter the frequency using the numeric keypad.
  3. Select [GHz], [MHz], [kHz], or [Hz].
  4. OR by:
  5. [Pointer to Peak]
  6. Enter the frequency using the numeric keypad.
  7. Select [Pointer To Next Peak] to mark successively lower peaks.
The number displayed at the bottom of the Pointer to Peak button indicates the number of the marked peak and the total number of peaks. For example, 1/22 indicates the peak with the highest power on the display and a total of 22 peaks displayed. 2/22 would indicate the second highest peak, 3/22 the third highest, and so forth.
 Pointer to Peak always returns the marker to the highest peak.
10
 		You can set the threshold level to automatically set value or manual select a value by:
  1. On [Threshold] select Auto
  2. Or
  3. On [Threshold] select Manual
  4. Enter the threshold value using the numeric keypad.
  5. Select [dBm].
The threshold limit line is displayed on the graticule at the desired level. Ensure that the threshold value you enter is within the graticule range or the threshold limit line will be off the display.
 The threshold is used to determine the "edges" of the signal. Manual adjustment may be required to correctly identify some signals, especially in crowded spectrums.
11
 		You can set center frequency of the display to the marker frequency by:
  1. [Zoom to Signal]
  2. [Zoom In]
The marker will track with the new center frequency at the center of the display. The Span will be decreased to enhance viewing of the designated interference signal.
12
 		Under [Zoom to Signal] you may also select [Zoom Out]
 		[Zoom Out] will back out the [Zoom In] series. If you Manually set the Frequency/Channel or Span, it will clear the [Zoom Out] history.