Table of Contents
Advertisement
VF Longitudinal Balance Test
This test applies a locally-generated common-mode disturbing tone to the pair,
and simultaneously measures the metallic noise caused by this tone.
Longitudinal balance is the difference in dB between the two signals.
Setting Up a VF Longitudinal Balance Test
Enter setup parameters as instructed in Chapter 3, referring to Table 4-9.
Table 4-9. VF Longitudinal Balance Setup Parameters
Parameter
Pass Threshold
Disturbing Frequency
VF Longitudinal Balance Test Results
Figure 4-28 shows VF Longitudinal Balance test results on a good pair.
The Longitudinal Balance result is shown in the upper right corner of the
screen, along with setup information.
represents the locally applied disturbing tone, and
Vg
metallic signal due to resistive or capacitive imbalance to Ground.
Longitudinal Balance
Press A(
Contin. VF Long. Bal.
POTS Testing and Fault Location
≥60 dB
1000 Hz
(dB) =
(dBm) –
Vg
) to view continuous test results.
The POTS Toolbox
Setting (default in bold)
(Range = 0 to 80)
(Range = 200 to 2500)
is the resulting
Vm
(dBm)
Vm
4
4-47
Advertisement
Table of Contents
