80 Keysight N9923-90001 User’s GuideCAT (Cable and Antenna Test) ModeCAT Mode Settings— Ref Level Manually set the value of the reference line.Enter a negative value by pressing Run/Hold (+/-) eitherbefore or after typing a value— Ref Position Manually set the position of the referenceline. Values must be between 0 (TOP line) and 10(BOTTOM line)3. Set Top and Bottom graticule values. The scale per division iscalculated.— Top to set the value of the Top graticule.— Bottom to set the value of the Bottom graticule.— Enter a negative value by pressing Run/Hold (+/-) eitherbefore or after typing a value.AveragingTrace Averaging helps to smooth a trace to reduce the effects of random noiseon a measurement. The FieldFox computes each data point based on theaverage of the same data point over several consecutive sweeps.Average Count determines the number of sweeps to average; the higher theaverage count, the greater the amount of noise reduction.An average counter is shown in the left edge of the screen as Avg N. Thisshows the number of previous sweeps that have been averaged together toform the current trace. When the counter reaches the specified count, then a‘running average’ of the last N sweeps is displayed. Average Count = 1 meansthere is NO averaging.This setting can be changed at any time without affecting calibration accuracy.How to set Trace Averaging— Press BW 2.Scale annotation on the FieldFox screenReference Line = red arrowRef Level = -40 dBRef Position = 1Scale = 2 dB per divisionAveraging is often used to increase the dynamic range of a measurement.To achieve the highest dynamic range, select NA mode and reduce the IFBandwid th setting. Learn more about dynamic range in “Increase DynamicRange” on page 58.
