Keysight N9938-90003 User’s Guide                 39
CAT (Cable and Antenna Test) Mode
CAT Mode Settings
CAT Mode Settings
Select CAT Mode before making any setting in this chapter.
How to select CAT Mode
—Press Mode. 
—Then CAT/TDR.
Measurement Selection
How to select a CAT Mode Measurement
Learn more about the following measurements in the Supplemental Online 
Help: http://na.support.keysight.com/fieldfox/help/SupHelp/FieldFox.htm
Press Measure   1
.
Then choose one of the following: These softkeys also appear after CAT Mode 
is selected.
— Distance To Fault
 1-port reflection measurement that uses Inverse Fourier 
Transform (IFT) calculations to determine and display the distance to, and 
relative size of, a fault or disruption in the transmission line. Units are in 
return loss format, expressed as a positive number in dB, unless the 
measurement selected is DTF (VSWR). Learn more about DTF 
Measurements refer to Chapter 4, “DTF (Distance to Fault) 
Measurements.”.
— Return Loss & DTF
 Displays both a Return Loss measurement and a DTF 
measurement. Use this format to display the frequency settings that are 
used to make the DTF measurement. The frequency range settings for these 
two measurements can be coupled or uncoupled. Learn more on page 46.
Calibrations are applied to both traces
When in Hold mode and Single sweep is performed, only the active 
trace is triggered. Use the   arrows to activate a trace
— Return Loss
 1-port reflection measurement that displays the amount of 
incident signal energy MINUS the amount of energy that is reflected. The 
higher the trace is on the screen, the more energy being reflected back to 
the FieldFox. Learn how to measure Return Loss on page 48.
— VSWR
 (Voltage Standing Wave Ratio – also known as SWR) 1-port 
reflection measurement that displays the ratio of the maximum reflected 
voltage over the minimum reflected voltage. The higher the trace is on the 
screen, the more energy being reflected back to the FieldFox.
— DTF (VSWR)
 Distance to Fault in VSWR format.