6
Version 2.0.0
6
A
ERIAL
M
ODE
The Aerial mode uses a high-gain audio monitor to display signal levels. A time-based graph is displayed
providing a history of signal strength along with a matching audible tone. The graph is extremely useful when
analyzing signal level changes as the sensor is moved over the cable.
The graph records from left to right and takes approximately 20 seconds to complete the initial pass. The graph
then shifts left by one-half screen and continues recording signal levels.
6.1
F
AULT
L
OCATION
C
ONCEPT
Fault location is accomplished by measuring the signal received from the cable. Current flow through the
fault requires a source voltage and a complete path for the current. The ST-101, or other transmitter,
provides the source voltage and the resistive fault completes the path back to the source. This means
open faults, bridge tap, and other non-resistive faults are not located using the SR-101.
The technician monitors the cable at points along the cable to determine if the tone is present and
comparing the tone with the last position. Depending on the fault type, the tone will be significantly
lower, shorts and crosses, or higher, splits.
The location of the fault can be confirmed by moving back to a location between the fault and the
transmitter and comparing the signals.
6.2
F
AULT
T
YPE
I
DENTIFICATION
Use a cable pair test set, such as the D-105, to identify the type fault to be located. Estimate the distance
to the fault from the test location.
The following aerial resistive faults may be located:
•
Short Tip connected to Ring
•
Cross Tip or Ring of one pair is connected to the Tip or Ring of another pair
Signal decreases when
passed a resistive fault
such as a Short, Cross.
