Humminbird 917C - Manual (Page 31)

4. Fill the hull with enough water to submerge the transducer body.
Use a sand-filled bag or other heavy object to hold the transducer in
position. The transducer cannot transmit through air, and the water
purges any air from between the transducer and the hull, and fills
any voids in the coarse fiberglass surface.
5. View the sonar signal on the display and compare against what you
observed in Step 2, making sure that the boat is in the same location
as it was during your observations in Step 2. If the results are
comparable, move on to Step 6. Otherwise, locate a new position in
the hull and repeat Steps 3 through 5.
6. Run the boat at various speeds and water depths while observing
the screen on the control head. If depth performance is required,
test the transducer in water at the desired depth. If the performance
is acceptable, move on to Step 7. If the performance is not
acceptable, repeat Steps 3 through 6.
7. Once you have determined the best mounting location using the
above steps, mark the position of the transducer.
3. Route the cable
1. Once the mounting location is determined and you have marked the
position of the transducer, route the cable from the transducer to
the control head.
4. Permanently mount the transducer
1. Make sure the position of the transducer is marked.
2. You may have to disconnect the cable to the control head and
reconnect it at the end of this procedure.
3. Remove the water from inside the hull and thoroughly dry the
mounting surface. If the surface is excessively rough, it may be
necessary to sand the area to create a smooth mounting surface.
4. Slowly and thoroughly mix an ample quantity of two-part slow cure
epoxy. Avoid trapping air bubbles.
5. Coat the face of the transducer and the inside of the hull with epoxy.
6. Press the transducer into place with a slight twisting motion to
purge any trapped air from underneath, keeping the end of the
transducer that has the mounting ears pointed forward, towards the
bow of the boat.
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