Inductive Antenna Description; Application Tips - Textron Greenlee 501 Tracker II Manual De Instrucciones

Inductive Antenna Description

The inductive antenna (See Fig. 13) is used to apply a tracking tone into a cable,
wire or metallic pipe by radiating a signal from the ground surface. This method is
used when there is no accessible way to make a direct connection.
The inductive antenna or transmitter loop is fitted inside the carrying case of the
501 System and is powered by the Model 501T transmitter.
Operation
Plug the two antenna leads into the 501T transmitter. Turn transmitter to full power;
place the transmitter in its compartment with the leads facing to the rear of the
case. Close the carrying case. (See Fig. 14) Place activated antenna on the ground
parallel with and approximately one foot to either side of the utility to be tracked.
(See Fig. 14) Radius the area approximately 20 feet away from the inductive
antenna with the Tracker II receiver to determine the path. Proceed down the cable
path following the peak signal.
Note: As progress is made down the cable path, gradual increases in the gain
control of the receiver will be necessary to maintain reception.
Eventually reception will be effectively lost, even at the maximum transmitter
setting. Retrieve the antenna and place it at the point where the signal was last
effectively received.
Resume tracking the line and repeat the relocation of the inductive antenna as
necessary.
Searching for Underground Utilities
The activated inductive antenna will radiate the tracking signal through the ground
surface and the target utility will receive the signal and effectively transmit it down
the path.
One craftsperson will carry the antenna case close to the ground and move in a
specified direction.
Another craftsperson will hold the receiver (501R) at a distance of at least 20 ft.
away and simultaneously move parallel with the first person.
When the receiver is directly over a utility, strong signal will be detected.
(See Fig. 16)
Keep in mind that even though this is the easiest and most convenient way to
locate, caution should be used because the radiated signal may be induced into the
other utilities.

Application Tips

Remember that any conductive line in the immediate area can collect the radiated
signal. In locations such as trailer parks or other areas with congested facilities,
minor reductions in the transmitter output level may eliminate unnecessary signal
bleed.
The very nature of the inductive antenna may be a problem to the operator if he is
not prepared to pick up the tone from the antenna itself. Begin using the receiver 20
feet or more away from the antenna to avoid receiving signal on a direct basis.
Fig. 14 applies to situations involving shorter runs or work relatively close to the
antenna.
To achieve maximum distance, orient the activated antenna parallel to the suspect
path and set the Tracker II case up on its back, as shown in Fig. 15.
The inductive antenna is permanently installed and is weather sealed; no attempt
should be made to field repair the unit.
Provisions have been made to retrofit existing carrying case with the inductive
antenna.
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