Perform The Srl Cable Scan - Agilent Technologies 8712ET User Manual

Making SRL Measurements
How to Make and Interpret SRL Measurements

5. Perform the SRL Cable Scan

Once the connector model has been established for the best response, the
cable should be scanned at narrow frequency resolution to look for
narrow response spikes that are characteristic of periodic defects in the
cable. The SRL cable scan is required to determine the cable's SRL with
125 kHz resolution.
By taking five sweeps of 1601 points each at slightly different frequency
ranges (see
frequency points to achieve the desired frequency resolution of 125 kHz.
The resolution of the SRL measurement is determined by the following
formula:
where N is the number of measurement points. See the table below.
No Cable Scan
Using Cable Scan
1. With the cable under test still connected as shown in
2. The analyzer first displays a pop up message that says: Setting up
3. Pressing any key will abort the scan.
4-16
Table 4-3 on page
F
stop
Resolution = ------------------------------- -
F
start
5 MHz
5 MHz
5 MHz
press Cable
BEGIN
SRL Cable Scan.... The message Scanning Cable... appears while
the scan is in process.
4-17), the analyzer can obtain 8005 distinct
– F
start
N
F
stop
1000 MHz
1000 MHz
1000 MHz
SRL SRL Cable Scan
Option 100 Fault Location and SRL
N Resolution
201 4.95 MHz
1601 612 kHz
125 kHz
8005 125 kHz
Figure 4-4,
.