Fluke 990DSL - WB Longitudinal Balance and Send Tone

XDSL Testing and Loop Qualification
The XDSL Toolbox
5
5-35
WB Longitudinal Balance Test
The WB Longitudinal Balance test measures the metallic (T-R) effect of
applying a common-mode disturbing signal (single-tone or multi-tone set) on
the pair. This effect is directly related to the pair’s balance to Ground. The
CopperPro tester applies the common-mode tone(s) and measures the metallic
tone at the near end, thus not requiring a far-end termination device.
Setting Up a WB Longitudinal Balance Test
To set up a WB Longitudinal Balance test, select the test on the XDSL
Toolbox, and then press D(
Setups). Refer to Table 5-6 for setups.
Termination Impedance and Filters are automatically selected based on choice
of Tone Type and Frequency (< 1.2 MHz: 135 Ohms, 1.3 MHz Filter; >1.2
MHz: 100 Ohms, 20 MHz Filter). This test is restricted to the Pair 1 shielded
test lead set, which provides the measurement balance required for the
broadband frequency range (up to 18 MHz).
Table 5-6. Longitudinal Balance Test Setup Parameters
Parameter Setting (default in bold)
Disturbing Tone Type Multi, Single (Multi = 0.25 MHz to 17.5 MHz)
Disturbing Single Tone 25.000 kHz (Range = 25 kHz to 17664 kHz)
Long. Balance Pass
Threshold
30 dB (Range = 0 to 100 dB)
Running a WB Longitudinal Balance Test
To run a WB Longitudinal Balance test, select WB Long. Balance from the
XDSL Toolbox and then press K.