Keysight Technologies FieldFox A Series, User Manual

Page: 79 / 756

Keysight N9927-90001 User’s Guide 79
TDR (Time Domain Reflectometry) - Option 215
TDR Measurement Settings
— Clear All then Yes . Remove all Freq/Loss pairs from the table and
resets header information
— Press Done to close the Cable Editor.
How to Save or Recall a Cable
— Press Save Cable to save your changes to the specified Storage Device.
Enter a filename using the FieldFox labeler (see “How to use the FieldFox
labeler ” on page 674 . Learn more about Cable files below
— Press Recall Cable to load a Cable file from the specified Storage Device
— Storage Device Changes the device used to save or recall Cable files. This
is a different setting from the Save/Recall Storage Device setting. Choose
from Internal (default setting),
USB (must be connected) or SD card.
About Cable files
— Cable files are saved to, and recalled from, the Cables folder. If the folder
does not already exist on a USB or SD card, it is created automatically
before storing the file.
— Cable files are stored as *.xml files. Existing cable files that are preloaded
into the FieldFox firmware can be overwritten. Your edited file will NOT be
overwritten when firmware is updated.
— To DELETE a Cable file, use the Manage Files feature. Learn more in
“Manage Files” on page 680 .
How the Freq/Loss pairs are applied
When the cable file contains one Freq/Loss pair, that correction value is
applied to the entire displayed frequency span.
When the cable file contains two or more Freq/Loss pairs, the Loss value that is
used is interpolated from the Freq/Loss pairs and the TDR center frequency.
For example, using a cable file with the following Freq/Loss pairs:
The center frequency for the measurement is determined from the calculated
(Stop – Start) frequency values (seen on the second page of TDR Settings):
1 GHz: 0.1 dB/m
2 GHz: 0.2 dB/m
Calculated Start = 2.0 MHz
Calculated Stop = 3.598 GHz
Center Freq = 1.80 GHz