Installing The Transducer - Garmin GPSMAP 392, 398, 492, 498 Owner's Manual

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PPENDIX NSTALLING THE RANSDUCER

Installing the Transducer

The transducer acts as the eyes and ears of your new sonar. Proper
transducer installation is critical to the operation of your unit. The
transducer transmits sound waves toward the bottom in a cone
shape. The larger the cone angle, the larger the coverage area at a
given depth.
Wide cone angle
Narrow cone angle
Dead zone
fish not seen
90
X
X
A wide cone angle transducer works best in shallow water. The
wide cone angle provides a large coverage area, but at a decreased
bottom resolution. In deeper water this can result in a large dead
zone where fish cannot be seen. A narrow cone angle transducer
is better suited to deep-water installations. The narrow cone angle
provides a smaller viewing area (compared to a wide cone angle
transducer at the same depth) with improved bottom resolution and
a smaller dead zone. Dual frequency transducers give you the best
of both wide and narrow cone angles.
A 50/200 kHz dual frequency 40°/10° cone angle, temperature
sensing, transom mount transducer is included in the GPSMAP 498
(with transducer) package. This transducer provides good all-
around performance.
A 80/200 kHz dual beam 40°/14° cone angle, temperature sensing,
transom mount transducer is included in the GPSMAP 398 (with
transducer) package. This transducer provides good all-around
performance.
GPSMAP 392/398/492/498 Owner's Manual