1-95
Making Measurements
Using Bandwidth Limits to Test a Bandpass Filter
Activating the Bandwidth Test
1. Start the bandwidth test by pressing the softkey until ON is
displayed.
The bandwidth test continues to run until the softkey is returned to the OFF position.
The test displays a message in the upper left corner of the graticule showing that the
bandwidth test is being performed and the channel on which the test is being
performed. For example, BW1: indicates that the bandwidth test is being run on
channel 1. See Figure 1-74.
The test also displays a message indicating whether the filter passes or fails the
bandwidth test. When the filter is passing the test, the message indicates Pass. When
the filter is failing the test, the failure message indicates either Wide (when the pass
band is wider than the maximum bandwidth input) or Narrow (when the pass band is
narrower than the minimum bandwidth input).
When the filter passes the bandwidth test, the color of the bandwidth test Pass message
is green. When the filter fails the bandwidth test, the color of the bandwidth test
Wide/Narrow message is red.
Figure 1-74 Filter Pass Band with Bandwidth Test Activated
Displaying the Bandwidth Markers
1. Display the bandwidth markers by pressing the softkey until
ON is displayed on the softkey.
When the bandwidth markers are displayed, a marker is placed on each side of the peak
amplitude at a position equal to the N dB Points value below the peak. The markers are
placed at the 40 dB points on the signal in Figure 1-75. The bandwidth markers
resemble the following symbol: T
BW TEST on OFF
BW MARKER on OFF