51
Measuring a Low−Level Signal
Using the Average Detector and Increased Sweep Time
6 Select the average
detector.
• Press Trace/Detector,
More 1 of 2, Detector,
Average (Log/RMS/V).
The number 1 (Trace 1 indicator) in the
Trace/Detector panel (in the upper
right-hand corner of the display)
changes from green to white, indicating
that the detector has been chosen
manually. In addition, the letter in the
Det row has been set to “A” indicating
that the Average detector has been
selected. See Figure 3-5.
7 Increase the sweep time. • Press Sweep/Control,
Sweep Time (Man), 100,
ms.
The noise smooths out, as there is more
time to average the values for each of the
displayed data points.
8 Change the average type
to log averaging.
• Press Meas Setup,
Average Type, Log-Pwr
Avg (Video).
Note how the noise level drops.
Figure 3-5 Varying the sweep time with the average detector
Step Action Notes