501
Locating the End of an Open Cable
Follow the peak receiver indications as outlined in the "Operating
Receiver" section. Reception of the signal will diminish rapidly and
be lost once past the end of the cable. (See Fig. 4)
Note: These results may not be achieved if the faulted cable
occupies a common trench that is congested with other wires or
cables.
Locating Underground Cable Splices
Locate and mark cable path as described in the "Locating Path"
section of this practice. Place 501 receiver antenna parallel to
cable path. (See Fig. 5)
Keeping the receiver antenna parallel with the cable, proceed
down the cable path. Watch and listen for increases in signal
(peaks). (See Fig. 6)
Fig. 4. Locating the End
of Open Cable
When the increase in signal is seen, check to see if it continues to
the left or right of the cable path. A signal that continues out to
either side of the cable path is a drop wire or branch cable. Mark
these paths. (See Figures 7 & 8)
A peak in signal without a continued path indicates the presence
of a splice. Mark this point. (See Fig. 6)
A branch splice will peak over the cable path, and then a peak
can be followed over the path of the branch cable. (See Fig. 7)
Note: The same signal can be produced by a drop wire running
parallel to the cable from a splice at the point it turns 90° from
the cable path.
Fig. 5. Signal Over Cable
with No Splice
Fig. 6. Signal Changes Over Splice
Fig. 7. Signal Over
Branch Splice
7