Introduction - NorthStar EXPLORER 443S Installation And Operation Manual

1 Introduction

Congratulations on choosing a Northstar
fishfinder. For maximum benefit, please read this
manual carefully before installation and use.
This manual describes the installation and operation
procedures for the Explorer 443s/443sp.
The Northstar Fishfinder
The Explorer 443s/443sp is an ultrasonic fishfinder
with four levels of greyscale. It provides powerful
software and a large, high-resolution screen with
a zoom facility and a choice of fish symbols. As
well as detecting fish, the Explorer 443s/443sp
measures the water depth, battery voltage,
engine hours and water temperature.
The Explorer 443sp also measures boat speed and
has two distance logs (Trip Log and Total Log).
An installed Explorer 443s/443sp has two parts:
- The transducer attached to the hull.
- The display unit.
The transducer generates an ultrasonic pulse
(sound that is above the hearing range of the
human ear), which travels down towards the
bottom, spreading out into a cone shape.
When the pulse meets an object, such as a fish
or the bottom, some of the pulse is reflected
back up towards the boat and is received by
the transducer. The depth of an object can be
calculated by measuring the time between
sending the pulse and receiving its echo. The
Northstar Explorer 443s/443sp will detect
the bottom down to 600 feet (180 metres),
depending on the clarity of the water and the
type of transducer used.
The strength of an echo can vary for a number
of reasons. Larger fish usually return stronger
echoes, and so do fish in the middle of the
cone, where the pulse is strongest. Reasons for
weak echoes include the fish or object being in
deep water, turbid water or in the edge of the
cone where the pulse is weakest. Turbid water
scatters the ultrasonic pulse and is difficult to
'see' through. Turbidity can be caused by air in
the water (e.g. from another boat's wake) or by
mud in the water.
Northstar Explorer 443s/443sp Installation and Operation Manual
Important
It is vital to the performance of the fishfinder that
the transducer is installed in the best location.
Please follow the instructions in the Transducer
Installation manual very carefully.
All of the Northstar 400 Series fishfinders use
proprietary SBN Technology for sonar processing to
improve signal enhancement, bottom recognition
and noise rejection. SBN Technology uses the
latest in digital adaptive filter algorithms to
enhance all returned signals. At the same time,
SBN Technology uses active noise control to
reject interference, which can often be mistaken
by fishfinders for true returns. Using SBN
Technology, the Explorer 443s/443sp analyses the
reflections from each pulse, filters false returns,
and displays what is in the water under the boat.
The distinctions between the four levels of
shading help the user to better interpret what is
in the water and what type of bottom is under
the boat.
Assisting with navigation
The Explorer 443s/443sp can be used to find
fish, to locate features on the bottom such as
reefs or wrecks, and to help recognise favorite
fishing spots from the profile of the bottom. Use
the Northstar fishfinder to assist navigation by
following the depth contours marked on charts.
CAUTION
!
IMPORTANT NOTE ON USE. While any fishfinder
can be used as an aid to navigation, accuracy
can be influenced by many factors including
the location of the transducer. It is the user's
responsibility to ensure that the Explorer
443s/443sp is installed and used correctly.
How to find fish
Underwater features like reefs, wrecks and rocky
outcrops attract fish. Use the Explorer 443s/443sp
to find these features, then look for fish by
passing over the feature slowly several times
using the ZOOM screen (see section 3-4). Where
there is a current, the fish will often be found
downstream of the feature.
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