Humminbird 120 Fish Finder User Manual


 
INSTALLATION PREPARATION
INSTALLATION OVERVIEW
Determining How to Mount the Transducer
Your Humminbird fishfinder includes a standard
transducer. This transducer can be mounted on the
transom of the boat or bonded to the inside of a fiberglass
hull boat.
The transom installation, which is the most widely used,
places the transducer on the outside of the boat hull. This
technique produces the least signal loss, and provides a
way to adjust the transducer after installation. The
mounting hardware included is designed to protect both
the boat and the transducer should the boat strike debris in
the water or when trailering.
As an alternative to transom mounting, it is possible on many
fiberglass-hulled boats to glue the transducer on the inside of
the boat hull. Since fiberglass has similar sonar
characteristics as water, the sonar signal can pass through
the boat hull with minimal loss. The hull of the boat must be
single layer construction (not double-hulled) Also, any air
trapped in the lamination of the fiberglass would prevent the
sonar signal from passing through.
Inside the hull installations require no holes be drilled into the
boat and through experimentation, high-speed operation
comparable to transom mounting can be achieved. Two-part slow cure epoxy (not
included) is required to glue the transducer in place.