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Fig. 8. Signal Over Dropwire Splice
Inductive Coupler
Description
The inductive coupler is designed to induce
a tracking tone into a subject cable or wire
without establishing metallic contact or
removing bonds. (See Fig. 9)
The inductive coupler is constructed of
plastic and iron and can accommodate up to
a 3 inch cable.
Operation
Clamp the inductive coupler around the insulation of the buried cable to be tracked. The
coupler must be completely closed to transmit the maximum signal. Connect both transmitter
leads to the two terminals on the face of the coupler. Turn transmitter on to approximately a #5
output setting and radius the immediate area with the Tracker II receiver to determine path. The
power output may be increased for greater distance.
Positioning of Coupler
1.
Coupling Points: The bond is one aspect which enables the inductive coupling method
to work. For proper placement of the clamp at a pedestal, place it between the bonding
point and the point where the cable goes into the ground. In CATV applications, these
positioning points would be at the end of the main line or at the subscriber's house.
Applying the coupler above the bond will effectively "block" the tone from transmitting
past the grounding point. (See Fig. 10) By strategically placing the clamp in the direction
of the transmitter, tone may be controlled.
2.
Mid Run Coupling: If the subject cable is relatively long, current is permitted to flow
back through earth as tone is transmitted in both directions. (See Fig. 11)
3.
Near End Coupling: To supply tone from the end of a cable, the end of the cable must
be bonded or grounded. (See Fig. 10)
4.
Reduced Tone At Branch: When tone is applied to a cable which has a branch, the
tone will be split and be effectively decreased relative to each conductor's length and size.
(See Fig. 12)
Fig. 9. The Inductive Coupler
Fig. 10. Coupling Points
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