Bottom Line Fishin Buddy 4200 Operation Manual page 8

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FISHING WITH THE FISHIN' BUDDY 4200™
HOW YOUR FISHIN' BUDDY 4200™ WORKS
The Fishin' Buddy 4200™ uses active SONAR, short for Sound Navigation and Ranging, to locate
and identify objects in the water. The transducer sends out short bursts of ultrasonic sound waves
into the water and then listens for echoes to come back from objects and the bottom. The further
away the object or bottom is, the longer it takes the echo to return.
These ultrasonic waves "illuminate" the water, forming a beam that is strongest in the direction
that the transducer is pointed. Weaker side-lobes split off from the main beam and with enough
gain can be used for finding fish as well. You can calculate the approximate diameter of the main
beam on the bottom as the depth divided by six.
Fishin' Buddy 4200™ Display
SONAR beam (cross-section)
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