Garmin Dual Frequency Installation Instructions - Page 2

6. Make sure that the transducer is aligned parallel with the water line. 7. Tighten the 10-32 locking nut until it touches the mounting bracket and then tighten 1/4 turn more (do not overtighten). 8. If you would like to route the cable through the transom, choose a passthrough location well above the waterline ➍ and mark it. 9. Use a 5/8 in. (16 mm) drill bit to drill a pass-through hole completely through the transom. 10. Place a cable clamp on the transducer cable ➎, approximately one third of the distance between the transducer and the top of the transom or the pass-through hole. 11. Mark the pilot-hole location for the cable clamp, and, using a 1/8 in. (3.2 mm) bit, drill a pilot hole approximately 3/8 in. (10 mm) deep. 12. Apply marine sealant to the included 12 mm M4 screw, and attach the cable clamp to the transom. 13. Repeat steps 10-12 to install the other cable clamp approximately two thirds of the distance between the transducer and the top of the transom or the pass-through hole. 14. Route the transducer cable to the sounder. • If you are routing the cable using a pass-through hole, feed it through the hole you drilled in step 8, and install the cable-entry cover ➍ (page 2). • If you are not routing the cable using a pass-through hole, route the cable up and over the top of the transom ➏. Avoid routing the cable close to electrical wires or other sources of electrical interference. Installing the Cable-Entry Cover If you routed the cable through the transom after you installed the transducer, install the cable-entry cover to keep water from entering your boat. 1. Place the cable-entry cover ➊ over the hole and the cable, with the opening pointing downward, and mark the location of the two pilot holes. ➊ 2. Remove the cable-entry cover, and, using a 1/8 in. (3.2 mm) bit, drill the pilot holes approximately 3/8 in. (10 mm) deep. 3. Fill the pass-through hole with marine sealant so that it covers the cable completely, and so that there is excess sealant around the hole and the cable. 4. Place the cable-entry cover over the hole and the cable, with the opening pointing downward. 5. Apply marine sealant to the included 12 mm M4 screws, and attach the cable-entry cover to the transom. 6. Wipe away any excess marine sealant. Testing the Installation Notice Do not leave your boat in the water for an extended period of time without checking for leaks. Because water is necessary to carry the sonar signal, the transducer must be in the water to work properly. You cannot get a depth or distance reading when out of the water. When you place your boat in the water, check for leaks around any screw holes that were added below the water line. Testing the Transom-Mount Transducer Installation Notice When adjusting the depth of the transducer, make the adjustments in small increments. Placing the transducer too deep can adversely affect the performance of the boat and put the transducer at risk of striking underwater objects. Test the transom-mount-transducer installation in open water free of obstacles. Pay attention to your surroundings as you test the transducer. 1. With the boat in the water, turn on the sounder. 2. Drive the boat at a slow speed. If the sounder appears to be working properly, gradually increase speed while observing the screen. If the sonar signal is suddenly lost or the bottom return is severely degraded, note the speed at which this occurs. 3. Return the boat to the speed at which the signal was lost, and make moderate turns in both directions while observing the screen. 4. If the signal strength improves while turning, adjust the transducer so that it extends another 1/8 in. (3 mm) below the transom of the boat. 5. Repeat steps 2-4 until the degradation is eliminated. 6. If the signal does not improve, move the transducer to a different location on the transom. About Transducer Fine Tuning To obtain the most symmetrical arch returns from the sounder, the transducer should be level with the water. For the best speed performance, the transducer should be tilted forward slightly. Tilting the transducer forward improves the clean water flow over the transducer by reducing cavitation bubbles. When the transducer is tilted forward, though, it is no longer level with the water, and the arch returns become skewed. Adjusting the Transducer Angle You can adjust the transducer angle to provide the most symmetrical arches at the desired speed. 1. With the boat in the water, turn on the sounder. 2. Drive the boat at a slow speed and observe the symmetry of the arch returns. 3. Slowly increase speed until the sonar signal is lost, the bottom return is severely degraded, or you have reached an acceptable speed at which you plan to use the sonar. Note the speed at which this occurs. 4. Complete an action: • If the arch returns look good, but the speed is not acceptable, tilt the transducer forward slightly and repeat steps 2-4 until you see the most symmetrical arches at the desired speed. • If the speed is acceptable, but the arch returns are skewed more than you like, tilt the transducer back slightly and repeat steps 2-4 until you see the most symmetrical arches at the desired speed. 2 Dual-Frequency Transducer Installation Instructions