Garmin 240 Fish Finder User Manual


 
1
Installation
Transducers
Transducers
The transducer acts as the eyes and ears of your new sonar. Proper
transducer selection and installation are critical to the operation of your
unit.
Included in the Optional Package is a 200/50kHz frequency (10°/40°
cone angle), depth and temperature sensing, transom mount transducer.
This transducer provides good all-around performance. Other optional
dual frequency transducers are available from your local dealer or GARMIN.
The transducer transmits sound waves toward the bottom in a cone
shape. The wider the cone angle, the larger the coverage area at a given
depth. While it is good to see as large of an area as possible, it is best to
select a frequency setting that suits the water that you are on.
With a dual frequency transducer, you may select either a 200kHz
frequency, a 50kHz frequency or both. The 50kHz frequency setting
provides a wide cone angle. This wide cone angle produces a large coverage
area, but less detailed bottom resolution. In areas where bottom contours
change quickly, this can result in “dead zones” where fish cannot be seen.
In contrast, the 200kHz frequency setting provides a narrow cone
angle. This narrow cone angle produces a smaller viewing area (compared
to a wide cone angle at the same depth), but with improved bottom
resolution and a smaller dead zone.
The Dual frequency setting will provide you the most accurate depth
and fish returns by transmitting signals at both 200kHz and 50kHz.
X
X
50 kHz
wide cone angle
200 kHz
narrow cone angle
dead zone
fish not seen
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