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can be supplied. The extra length enables the antenna
to be carried by a diver on a riverbed or seabed while the
locator is used in a surface vessel. It is crucial to have
effective communication between the operator with the
locator and the diver with the antenna.
Alternatively, the antenna can be fastened to the end of
a non-metallic boom from a barge and lowered to the
riverbed or seabed.
How to use a submersible antenna
Apply the transmitter signal to the target line at an
access point on the shore. The submersible antenna line
for tracing the line underwater is plugged into the
accessory socket of the locator. The locator is used
onboard a boat, which should by positioned directly over
the line. The transmitting signal should be applied by
Direct Connection with the strongest possible signal and
at the frequency that the submersible antenna is
calibrated to. Make a ground connection about 50m
(160ft) from the transmitter. Test the quality of signal on
the line before locating on the water.
NOTE: The submersible antenna is calibrated to work at
one frequency.
Tips for using a submersible antenna:
The user in the boat should be a specialist or have
considerable experience using a locator so that they can
give concise instructions to the diver.
It is prudent for the pair to practice working together on
dry land before attempting to locate underwater. Using
the antenna the diver should locate and trace a known
line blindfolded receiving directions from the user with
the locator out of sight of the line and the diver.
Because of rapid signal loss and a combination of large
surface area and very conductive soil there may be
problems applying a suitable signal for tracing a large
diameter pipe. It may be necessary to use a high power,
low frequency tracing signal.
It is necessary to define a method of recording target line
position and depth before starting work in the boat or on
the seabed.
Figure 9.11: Using a submersible antenna
WARNING! Only properly licensed and experienced
divers should attempt to use the submersible antenna
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