75
Measuring Noise
Measuring Noise Using the Noise Marker
7 Move the marker. • Press Marker, 50, MHz. The noise marker value is based on the
mean of 5% of the total number of sweep
points centered at the marker in the
initially selected span. The points that are
averaged span one-half of a division.
Changing spans after enabling the noise
marker will result in the marker
averaging a progressively wider or
narrower portion of the newly selected
span and corresponding sweep points.
This occurs because the marker is locked
to 5% of the initially selected span.
8 Adjust the width of the
noise marker relative to
the span.
• Press Marker Function,
Band Adjust,
Band/Interval Span, and
adjust the value to the
desired marker width.
Notice that the marker does not go to the
peak of the signal unless the
Band/Interval Span is set to 0 Hz because
otherwise there are not enough points at
the peak of the signal. With a Band
Interval Span greater than 0 Hz, the noise
marker is also averaging points below the
peak due to the narrow RBW.
9 Widen the resolution
bandwidth.
• Press BW, Res BW, 10,
kHz.
This allows the marker to make a more
accurate peak power measurement using
the noise marker as shown in Figure
7-2.
Step Action Notes