Inductive Coupler Description - Textron Company GREENLEE 501 Tracker II Manuel D'instructions

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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