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 pro-

 

portionately; 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 noise;

propeller

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 GR16 Finding the Cause of Noise, Possible Source of Noise Isolation Other electronic devices, Boat’s engine