6100-Gfast Multifunction Network Analyzer Operation Manual
102
© 2020 Radiodetection Ltd
Frequency
Tests
The purpose of the frequency tests is to perform VF
(voice frequency) and WB (wide band) level
measurements, calculate the reduction of signal
strength during transmission, measure the balance of a
circuit, and count and detect the presence of load coils.
To access frequency tests:
From the
Copper Main
pane, highlight
Frequency
Tests
and press
to open the menu.
12.1 Frequency Tests Main Page
The
Frequency Tests
menu allows you to select and
run the displayed tests:
VF/AC Balance
WB Balance
WB Attenuation
Return Loss
Load Coils
Locator Tone
TX/RX Tone
RX Tone with FED
To start/stop a test:
1. Press the up/down left/right arrow keys on the
keypad to select the desired test icon.
2. Press to confirm your selection.
3. The test will start automatically if the
Setup/Application Settings/General - Test
Startup Mode
is set to
Auto
. If not, press
Start/Stop on the keypad.
12.2 VF/AC Balance
The VF/AC Balance test allows you to check that the
VF longitudinal balance ratio for the twisted pair
complies with applicable standards so as to reduce the
effects of common-mode voltage to ground.
The test is a measurement of how much the T/A leg is
like the R/B leg in electrical characteristics, measured
by how much noise the line can mitigate (in dB). It is an
overall health indicator and a quick way to tell if the line
is in good condition. The better the longitudinal balance
of the cable pair, the higher the dB reading.
The name of the frequency test depends on the
selected Standard:
ANSI: VF Balance
ITU: AC Balance
Active
The
Active
function takes a balance measurement,
displaying and updating results in
real time
, until you
stop the test. The last valid results then remain
displayed.
