application and capabilities of this
instrument. The benefits of using the
LST-1700 include:
The Model LST 1700 can be
used as a portable tagger.
The Model LST 1700 can be
used to generate mini-sweep. The LST-
1700 can be inserted at the tap end of
the drop, or at the ground block and
used to measure subscriber terminal
locations using the Model CLI-1750.
The LST-1700 allows the installer to
look for significant variations in the fre-
quency response, which could include
standing waves, excessive loss, roll-
offs, or suck-outs.
The Model LST 1700 Signal
Transmitter can be used to pro-
vide a source for a frequency domain
reflectometry (FDR) test of in-house
wiring to help locate faults. Frequency
domain reflectometry is a method of
determining transmission characteris-
tics by analyzing the reflections in a
sweep response.
If a cable fault is buried, inside a wall,
or otherwise hidden, use the FDR
mode of the CLI-1750. More accurate
than TDR, the LST-1700 is used as a
sweep generator, injecting a sweeping
signal into the beginning of the net-
work (street, home, apartment build-
ing). Bad cables, connectors, taps,
splitters, etc. will cause reflections or
standing waves. Analyzing these
standing waves by the CLI-1750 gives
a distance-to-fault diagram; reflection
in dBrl vs. distance in feet or meters.
Set-Up and Use Your LST-1700
To use the LST-1700, simply connect
the LST-1700 to the cable outlet (usu-
ally from the tap source into the
home) and turn up the frequency. The
LST-1700 will send a signal through
the targeted residential system which
can be detected by the CLI-1750 meter.
3-22
Frequency
response in
MiniSweep
26 dB loss
30 dB slope
8 dB standing
waves
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