531526-1_A - 747c_&_777c2_Man_Eng.qxp 10/2/2006 1:42 AM Page 78

Finding the Cause of Noise

Electrical noise usually affects the display with many black dots at high speeds, and high sensitivity readings. One or more of the following sources can cause noise or interference:

Possible Source of Noise

Isolation

Other electronic devices Turn off any nearby electronic devices to see if the problem goes away, then turn them on one at a time to see if the noise re-appears.

The boat’s engine

To determine whether the boat’s engine is the

 

source of the noise, increase the RPMs while

 

the boat is in neutral and stationary to see if

 

the noise increases proportionately; if noise

 

appears when you rev the engine, the

 

problem could be the spark plugs, alternator,

 

or tachometer wiring. Replace the spark plugs

 

with resistor plugs, install an alternator filter,

 

or route the control head power and

 

transducer cables away from the engine

 

wiring.

Cavitation from the boat’s

Turbulence created by the propeller can cause

propeller

noise; make sure the transducer is mounted at

 

least 15” (38 cm) from the propeller, and that

 

the water flows smoothly over the face of the

 

transducer at all times.

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Humminbird 747c, 777c2 manual Finding the Cause of Noise, Isolation
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747c, 777c2 specifications

The Humminbird 777c2 and 747c are exemplary fish finders that have made a significant impact on the fishing community, offering a host of features and technologies aimed at enhancing the angling experience. These devices are particularly revered for their user-friendly interfaces and advanced sonar capabilities, catering to both novice and seasoned fishermen alike.

One of the main features of the Humminbird 777c2 is its high-resolution color display. The 7-inch screen provides vibrant visuals, allowing users to easily interpret sonar readings and underwater structures. The screen's clarity ensures that users can spot fish and understand their surroundings in a variety of lighting conditions.

The DualBeam PLUS sonar technology in both models allows for versatility in fishing. This technology combines a wide cone beam for locating fish in a broader area with a narrow beam that provides detailed imaging of the bottom. This dual capability allows anglers to adapt their strategies depending on the fishing situation, whether they are exploring shallow waters or searching deeper depths.

Another notable characteristic is the built-in GPS functionality. The Humminbird 777c2 and 747c come equipped with advanced mapping capabilities, including the ability to create and save waypoints. This feature is a game-changer for fishermen, as it enables them to mark productive fishing spots and navigate efficiently back to them. The integration of navionics charts enhances navigation, providing detailed maps of lakes and coastal waters.

Furthermore, both models boast a user-friendly menu system, making it easy to adjust settings and access various functions. The interface is designed to minimize distractions, allowing users to focus on fishing. Customizable display options enable anglers to tailor the information they see, ensuring that vital sonar data is always at their fingertips.

The durability of the Humminbird 777c2 and 747c is another critical aspect, as these devices are built to withstand harsh marine environments. With weatherproof casings and reliable power sources, anglers can trust that their fish finder will perform consistently, even in challenging conditions.

In conclusion, the Humminbird 777c2 and 747c represent some of the best technology available in modern fish finders. With features such as a high-resolution color display, advanced sonar capabilities, built-in GPS, and a rugged design, these devices significantly enhance the fishing experience, making them a worthwhile investment for anyone serious about the sport.
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