Page 1
Explorer 435/438
Fishfi nder
Installation and Operation Manual
www.northstarnav.com
Page 2
Page 3
IMPORTANT SAFETY INFORMATION
Please read carefully before installation and use.
This is the safety alert symbol. It is used to alert you to
DANGER
!
WARNING
!
CAUTION
CAUTION
potential personal injury hazards, Obey all safety messages that
follow this symbol to avoidpossible injury or death.
WARNING indicates a potentially hazardous situation which, if
not avoided, could result in death or serious injury
CAUTION indicates a potentially hazardous situation which, if
not avoided, could result in minor or moderate injury.
CAUTION used without the safety alert symbol indicates a
potentially hazardous situation which, if not avoided, may
result in property damage.
DISCLAIMER: It is the owner’s sole
responsibility to install and use the instrument
and transducers in a manner that will not cause
accidents, personal injury or property damage.
The user of this product is solely responsible for
observing safe boating practices.
BRUNSWICK NEW TECHNOLOGIES INC. AND ITS
SUBSIDIARIES AND AFFILIATES DISCLAIM ALL
LIABILIT Y FOR ANY USE OF THIS PRODUCT IN A
WAY THAT MAY CAUSE ACCIDENTS, DAMMAGE
OR THAT MAY VIOLATE THE LAW.
Governing Language: This statement,
any instruction manuals, user guides and
other information relating to the product
(Documentation) may be translated to, or
has been translated from, another language
(Translation). In the event of any conf lict
between any Translation of the Documentation,
the English language version of the
Documentation will be the of ficial version of the
Documentation.
This manual represents the Explorer 435
and Explorer 438 as at the time of printing.
Brunswick New Technologies Inc. and its
subsidiaries and affiliates reserve the right to
make changes to specifications without notice.
Copyright © 2006 Brunswick New Technologies
Inc. Northstar™ is a registered trademark of
Brunswick New Technologies Inc
FCC Statement
Note: This equipment has been tested and found to comply with the limits for a Class B digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against
harmful interference in a normal installation. This equipment generates, uses and can radiate radio
frequency energy and, if not installed and used in accordance with the instructions, may cause harmful
interference to radio communications. However, there is no guarantee that interference will not occur in
a particular installation. If this equipment does cause harmful interference to radio or television reception,
which can be determined by turning the equipment off and on, the user is encouraged to try to correct
the interference by one or more of the following measures:
Reorient or relocate the receiving antenna.
Increase the separation between the equipment and receiver.
Connect the equipment into an output on a circuit different from that to which the receiver is
connected.
Consult the dealer or an experienced technician for help.
A shielded cable must be used when connecting a peripheral to the serial ports.
Page 4
Contents
1 Introdu ction .......................................................................................................................................... 6
1-1 Benefits of the Explorer 435 and Explorer 438 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1-2 How the Explorer 435 and Explorer 438 work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2 Basic Op eration ......................................................................................................................................8
3 Setti ng up the Explore r 435 and Explo rer 438 ....................................................................................... 10
3-1 Setup > System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3-2 Setup > Sonar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3-3 Setup > Fuel (Explorer 438 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3-4 Setup > Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3-5 Setup > Logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3-6 Setup > Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3-7 Setup > Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3-8 Setup > Comms (Explorer 438 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3-9 Setup > Calibrate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4 Using the E xplorer 435 and Expl orer 438 ............................................................................................... 16
4-1 Interpreting the display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
4-2 Fish detection and display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4-3 Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
4-4 Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
5 The Disp lays ......................................................................................................................................... 21
5-1 Sonar display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
5-2 Sonar Zoom display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
5-3 Sonar Bottom display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
5-4 Sonar A-Scope display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5-5 Fuel display (Explore r 438 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
5-6 Data display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
6 Instal lation and Mainten ance ..............................................................................................................24
6-1 What comes with this product? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
6-2 Options and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
6-3 Mounting and removing the display unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6-4 Wiring Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
6-5 Systems of several instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
6-6 Cleaning and maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Northstar Explorer 435/438 Installation and Operation Manual4
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Append ix A - Specifica tions ..................................................................................................................... 27
Append ix B - Troubleshooting ................................................................................................................. 28
Important
It is your sole responsibility to install and use Northstar’s instrument & transducers in a manner that
will not cause accidents, personal injury or property damage. Always observe safe boating practices.
The choice, location, angle and installation of the instrument & transducers are critical to
performance of the system as intended. Follow instructions in this manual carefully. If in doubt,
consult your Nor thstar dealer.
Ensure that any holes cut are in a safe position and will not weaken the boat’s structure. If in
doubt, consult a qualified boat builder.
Do not install plastic through hull transducers in solid wooden hulls. Leaking through the hull
may result.
Do not install bonze transducers in metal hulls. This will cause electrolytic corrosion that may
result in damage to the hull or transducer.
Sonar Performance: The accuracy of the sonar depth display can be affec ted by many factors,
including the type and location of the transducer and water conditions. Ensure that the transducer
is located and used correctly.
Fuel Computer: Do not rely on the fuel computer as the sole source of information regarding
available fuel onboard. Fuel economy can change drastically depending on boat loading and sea
conditions. Fuel Computer information should be supplemented by visual or other check s of the
fuel load. This is necessary due to possible operator errors such as forget ting to reset the fuel used
when filling the tank, running the engine with the Fuel Computer not switched on, or on other
operator ac tions that may render the device inaccurate. Always carry adequate fuel onboard for the
intended trip, plus a reserve to allow for unforeseen circumstances.
Failure to adhere to these warnings may lead to death, serious injury or property damage.
Northstar disclaims all liability for installation or use of this product that causes or
contributes to death, injury or property damage or that violates any law.
As Northstar is continuously improving this product we retain the right to make changes to the
product at any time which may not be reflected in this version of manual. Please contact your
nearest Nor thstar office if you require any further assistance.
The Explorer 435 and Explorer 438 are set up with default units of feet, °F (Fahrenheit), US
gallons and knots. See section 3-7 Setup > Units, to change the units.
Northstar Explorer 435/438 Installation and Operation Manual 5
Page 6
1 Introduction
Congratulations on choosing a Northstar fishfinder.
For maximum benefit, please read this manual
carefully before installation and use.
This manual describes how to install and set up
the Explorer 435 or Explorer 438. Refer to seperate
Transducer Installation Instructions supplied with
the transducer.
1-1 Benefit s of the Explorer 435 and Expl orer 438
The Explorer 435 and Explorer 438 are high quality
fishfinders that are supplied with a transducer.
Both use TFT (Thin Film Transistor) technology
to provide a color display for easy daylight
viewing. The LED backlight can be dimmed for
night fishing. The bracket mounting option also
allows the fishfinder to be tilted and swivelled for
optimum viewing.
The colors on the sonar displays are customizable, with a choice of four 16 color palettes
and one 8 color palette. The colors represent
different signal strengths, making the sonar
displays easy to interpret.
This capability, combined with a variable power
output of up to 200 W RMS, ensures that the
Explorer 435 and Explorer 438 operate effectively
in shallow and deep water.
The Explorer 435 and Explorer 438 can detect
the bottom to a depth of 600 feet (180 metres)
depending on the clarit y of the water and the
type of transducer used.
The Northstar fishfinder can be used to find fish,
to locate features on the bottom such as reefs or
wrecks and to help recognize favourite fishing
spots from the bottom profile.
The Northstar fishfinder can also assist with
navigation by providing depth information to
This manual also explains how to operate the
Explorer 435 and Explorer 438 ef fectively and
gives troubleshooting and performance tips.
Important
It is vital to the performance of the fishfinder
that the transducer is installed in the best
location. Please follow the installation
instructions very carefully.
CAUTION
IMPORTANT NOTE ON USE. While any
fishfinder can be used as an aid to navigation,
accuracy can be limited by many factors,
including the location of the transducer. It is
the user’s responsibility to ensure the Northstar
fishfinder is installed and used correctly.
help identify the depth contours marked on
charts.
With the optional fuel kit, the Exp lorer 43 8 also
becomes a sophisticated and easy-to-use
fuel computer.
All of the Nor thstar 400 Series fishf inders use
proprietary SBN Technology for sonar processing
to improve Signal enhancement, Bottom
recognition and Noise rejec tion.
SBN Technology uses digital adaptive filter
algorithms to enhance all returned signals. At the
same time, SBN Technology uses active noise
control to rejec t interference, which can often be
mistaken by fishfinders for true returns.
Using SBN Technology, the fishfinder analyses the
reflec tions from each pulse, filters false returns
and displays what is in the water under the boat.
See section 4-1 Interpreting the display, for more
information.
Northstar Explorer 435/438 Installation and Operation Manual6
Page 7
1-2 How the Explorer 435 and Explo rer 438 work
The Explorer 435 and Explorer 438 have 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 at a speed of about 4800 f t/sec
(1500 m/sec), spreading out into a cone shape.
When the pulse meets an object, such as a fish or
the bottom, it is partly reflected back up towards
the boat as an echo. The depth of the object
or bottom is calculated by the E xplorer 435
and Explorer 438 by measuring the time taken
between sending a pulse and receiving the echo.
When an echo has been returned, the next pulse
is sent.
The Explorer 435 and Explorer 438 convert each
echo into an elec tronic signal, displayed as a
vertical line of pixels. The most recent echo
appears on the extreme right of the display, with
the older echoes being scrolled towards the left,
eventually disappearing of f the display.
The scroll speed depends upon the water depth
and scroll speed setting. See section 3-2 Setup >
Sonar and section 4-1 Interpreting the display, for
more information.
The appearance of echoes displayed are af fected
by:
• the fishfinder settings (range and gain
settings)
• echoes (different fish t ypes, different bot tom
types, wrecks and seaweed)
• noise (water clarity and bubbles).
See section 4-1 Interpreting the display, for more
information.
Northstar Explorer 435/438 Installation and Operation Manual 7
Page 8
2 Basic Operation
Key Names
Returns to the previous menu / zooms in.
,
Cursor keys move the selection highlight and
change settings / scrolls up or down.
Confirms changes / zooms out.
MENU Press to show the Display menu
Press again to show the Setup menu.
+ Increases the Range.
_
Decreases the Range.
Press and hold to power On and Off; pressing once shows
the Gain controls. Press twice to show Backlight control.
Hold for Auto Range
Key Operatio n
The fishfinder is operated through menus.
To select a menu item:
1. Press
2. Press
To change a setting:
1. Use the cursor keys
2. Press
or to move the highlight to the
item.
to select the item.
change(s).
to confirm ; to cancel.
or
to make the
Power On / Auto Power
Press to turn the fishfinder on.
If the fishfinder is wired for auto power, it turns
on automatically whenever the boat’s ignition
Northstar Explorer 435/438 Installation and Operation Manual8
is turned on. This ensures that the engine hours
counter and optional fuel functions are activated.
A title display appear s briefly. This is followed
automatically by the Installation m enu only the
first time the fishfinder is switched on. Use this
menu to specif y the language (see section 3-1 Setup
> System) and units (see section 3-7 Setup > Units).
At all other times, the title display is followed by
the display that was used most recently.
If the transducer is not connected, the message:
No transduc er detected. Enter
simulate mode? will appear. Press
select and press to accept. (If the transducer
was not intentionally disconnected, turn off
the fishfinder and refer to the section on
Troubleshooting in Appendix B.)
or to
Page 9
Power Off
To turn the fishfinder off, hold . A countdown
box appears. Continue to hold for 3 seconds
until the fishfinder turns off.
Note: If the unit is wired for Auto Power (section
6-4 Wiring options) the fishfinder can be turned
off only when the boat’s ignition is turned off.
Simulate Mode
An internal simulator allows
users to learn how to operate
the fishfinder off the water.
In Simulate mode the word
Sim ulat e flashes at the
bottom of the display. The
fishfinder generates data
so that all the main displays
appear to be operational.
Use Setup > Simulate as follows:
1. Press MENU twice to show the Setup menu.
2. Highlight Simulate.
3. Press
to select On or Off.
Gain Adjustment
Gain (sensitivity)
controls the amount
of detail displayed on
the screen. Refer to
section 4-3 for more
information.
1. Press
2. Press
3. Press
4. Press
briefly
to show the gain
controls.
or to
adjust gain.
to switch between auto and manual
gain.
or MENU to confirm and exit.
Display Adjustment
The display and keys
are backlit, with a
choice of 16 brightness levels. To change
the backlight level:
1. Press
2. Press
3. Press
twice to
show the backlight
control.
to dim or
to brighten.
to confirm.
Northstar Explorer 435/438 Installation and Operation Manual 9
Page 10
3 Setting up the Explorer 435 and Explorer 438
Press MENU twice to show the Setup menu, then selec t a particular option using the
keys. (Section 2 Basic Operation, describes how to use the keys in more detail.)
The Setup menu and options are summarized below. The factory default settings are shown where
applicable. Each Setup menu option is explained in the following sections.
The Setup menu a nd options
System - see section 3-1 Sonar - see section 3-2
Data - see section 3-4
Fuel - see section 3-3
Logs - see section 3-5
Alarms - see section 3-6
Units - see section 3-7
or
cursor
Comms - see section 3-8
Simulate - see section 2
Northstar Explorer 435/438 Installation and Operation Manual10
Calibrate - see section 3-9
Page 11
3-1 Setup > System
Press MENU twice to display the Setup menu,
then select System:
Language
Select the language for the displays. The options
are: English, Italian, French, German, Spanish,
Dutch, Swedish, Portuguese, Finnish and Greek.
Tip: In case you can’t read the current langu age, the
language settin g is found at the top of the system
menu.
Backlight
The backlight control
is displayed. The bar
setting represents
the current level of
backlighting.
Key beep
Enables or disables the
beep when a key is
pressed.
3-2 Setup > Sonar
Press MENU twice to display the Setup menu,
then select Sonar:
Northstar Explorer 435/438 Installation and Operation Manual 11
Auto power of f
Select On to have the fishfinder power off
automatically every time the boat’s ignition is
switched of f. This applies only if the display unit
is wired for Auto Power. See section 6 -4 Wiring
Options.
Snooze Mode
This power
saving option
slows the
sounding rate
(time between
each ultrasonic pulse) to a user specified interval
from 5 minutes to 2 hours. The fishfinder appears
to turn off, however all alarms operate normally.
To return to normal operation, press any button.
Ideal to be used as an anchor alarm.
Factory re set
This option returns all of the fishfinder settings
(except the language) to the default factory
settings shown in section 3 Setting up the
Explorer 435 and Explorer 438.
“Reset to factory defaults?” appears.
Press to
select Yes or No. Then press MENU or
to reset and exit.
Scroll speed
Use this to set the scroll speed on the display. There
is a choice of: Very Fast , Fast, Medium,
Slow and Pause. The depth of the water also
affec ts the speed of the display.
Faster scroll speeds combined with a slow boat
speed (typically between 2 and 6 knots) shows the
most fish detail. Medium or Slow scroll speeds
result in sonar information being displayed over a
longer period, but wit h less detail. See Sec tion 4-1
Interpreting the display, for more information.
Fish f ilter
Use this to select the minimum fish symbol size to
be detected and displayed. There is a choice of:
Small, Medium and Large.
Page 12
Pale tte
Use this to selec t a color palette. Each color
within the palette represents a different echo
strength, as shown on the sonar displays.
There is a choice of five co lor palettes: Black, Blue,
White, Vivid and 8 color. The first four display
more detail, whilst the 8 color palette shows a
greater distinction of signal strength between
each adjacent color. For the 16 color palette, each
color covers 1.5 dB signal range. For the 8 color
palette, each color covers 3 dB signal range.
Color bar
This shows the range of colors used for the
selected color palette.
It can be switched On or Off. If switched On, it is
displayed down the left hand side of all the sonar
displays.
Digit size
Use this to change the size of the depth display
on the sonar displays. There is a choice of:
Small, Medium and Large.
Bottom lock
If Bottom lock is On, the zoom section moves
so the bottom is always displayed in the zoom
section, regardless of changes in depth.
If Bottom lock is Off, the bottom will not be
displayed in the zoom section when it is outside
the range covered by the zoom bar.
Using the Bottom Lock and the A-Scope features
together can be a powerful aid in recognising the
type of bottom.
Fish sy mbols
These appear only in the main sonar displays. Fish
symbols can be shown in three ways:
• As a fish symbol (On).
• As a fish symbol with the depth
(On+depth). The depth is shown beside the
fish symbol.
• Switched off (Off) so that echoes are not
converted to fish symbols but are displayed
directly.
See section 4-2 Fish detection and display, for
more information about fish symbols.
Interference filter
This filters the echo signal to reduce high-level,
spiky inter ference, such as engine noise.
It can be switched On or Off.
Data header
The data header can be turned On or Off.
When On, it is a customizable feature that can be
used to display up to 6 data items, such as boat
speed or fuel used.
To customize the size of the Data header,
highlight Size and press
Small and Large.
To customize the data items to be displayed:
1. Highlight Data setup and press
header increases in size to display all 6 data
fields. Some data fields may b e blank.
or to move from data fi eld to data field.
2. Use
3. Press
4. Highlight the required data item and press
5. Press
at any data field to show the list of data
items that can be displayed there.
. The data item is immediately displayed in that
data field.
or MENU when finished and the Data
header resizes automatically.
. There is a choice of
. The Data
3-3 Setup > Fuel (Explore r 438 only)
These features can
be used only when
the optional single
or twin engine
fuel kit has been
installed.
Press MENU twice
to display the
Setup menu,
then select Fuel:
Northstar Explorer 435/438 Installation and Operation Manual12
!
WARNING
Nor ths tar fuel kits are only suitable for petrol/
gasoline engines. Fuel cons umption can change
drastically depending upon the boat loading
and the sea conditions. Always carry adequate
fuel for the journey, plus a reserve.
Page 13
It is recommended that the fuel tank capacit y is
measured by draining the fuel tank, then filling it
to capacit y. After filling, note the reading from the
fuel dispenser’s gauge.
Note: Beware of air pocke ts, especially in underf loor
tanks .
Tan k full
Select Tank f ull each time the fuel tank(s)
are completely refilled. When asked Are you
sure? select Ye s. Otherwise, the reading on
the Fuel display (see section 5-5 Fuel Display) and
the Low Fuel Alarm (see section
3 -6 Setup > Alarms) are meaningless.
Set remaining
Before doing a partial refill of the tank or removing
fuel manually from the tank (for example, by
siphoning it of f):
1. Note the Remaining reading on the
Fuel display.
2. Note how much fuel is added or removed.
3. Calculate how much fuel is now in the tank.
4. Select Set remaining and update
the reading.
It is essential to do this whenever some fuel is
added or removed. Other wise, the reading on the
Fuel display (see section 5-5 Fuel Display) and
the Low Fuel Alarm (see section
3-6 Setup > Alarms) are meaningless.
3-4 Setup > Data
Press MENU twice to display the Setup menu,
then select Data:
Data setup
To change data items (Explorer 438 only):
1. Se le ct Data setup, and press
2. Use
field.
or
to move from data field to data
Clear Used
Select Clear used to set Used (the amount
of fuel used) to zero. Do this to start measuring
the amount of fuel used over a cer tain time or
distance.
When asked Are you sure? select Ye s.
Tan k size
Enter the capacity of the fuel tank.
Num. engines
Set the number of engines to 0, 1 or 2. If 0 is
selected the fuel features are turned of f.
Calib rate
See section 3-9 Setup > Calibrate.
Flow f ilter
Most engines do not draw fuel from the tank at a
steady rate. To give a stable fuel flow reading, the
fishfinder calculates the flow value(s) by taking
several measurements and averaging them. Use
the Flow filter to set the period over which the
fuel flow is averaged.
For twin engine installations, the fuel f low for
each engine must be adjusted separately.
The Flow filter can be set from 0 to 10 seconds.
Use the lowest value which gives a stable flow.
Usually a value of 5 seconds (default setting)
will give a satisfactory result for two -stroke
carburettor engines.
This setting affects the Fuel flow and Fuel
economy reading on the Fuel display (see
section 5-5. Fuel display) but it does not af fect the
Fuel used reading.
3. Press
4. Highlight the required data item and press
5. Press
at any data field to show the list of
data items that can be displayed there.
The data item is immediately displayed in that
data field.
or MENU when finished.
Time base
To change the Time base of the temperature
graph, select Ti me base and press . Choose
between 5 mins, 10 mins, 20 mins, 1 hour and 2
hours and press to confirm.
.
Northstar Explorer 435/438 Installation and Operation Manual 13
Page 14
3-5 Setup > Logs
Press MENU twice to display the Setup menu,
then select Logs:
The values can be changed independently of
each other. These log values are saved when the
unit is turned off.
Reset trip di st (Explorer 438 only)
This resets the trip distance to zero.
Reset total d ist (Explorer 438 only)
This option resets the total distance to zero.
Reset engine hours
Use this option to reset the engine hours to zero.
This can be useful after an engine service or to
count the engine hours between service intervals.
3-6 Setup > Alarm s
Press MENU twice to display the Setup menu,
then select Alarms:
Alarms can be set (enabled) to automatically detect
certain conditions, such as the water being too
shallow. Alarms that are enabled are shown as black
icons in the Alarm status box on the sonar displays.
When an enabled alarm is triggered, the beeper
sounds, an alarm message is displayed and the
alarm status icon is shown in red.
Press
the beeper and close the alarm window. This
does not disable the alarm.
Alarms automatically re-enable
Trigger settings can be defined to suit the boat
and individual preferences as follows:
c Alarm Beeper Alarm condi tion is
Name Cycle met when the:
Too
1
/5 sec depth is less than
shallow the alarm trigger value
1
Too
/2 sec depth is greater than
deep the alarm trigger value
Fish 1 short echo matches the fish
beep profile selected by
fish filter
1
Temp.
/2 sec temperature equals
the alarm trigger value
1
Temp.
/2 sec rate of change of
rate temperature equals the
alarm trigger value
1
Low
battery less than the alarm
/2 sec battery voltage is
trigger value
1
Low
fuel the alarm trigger value.
/2 sec fuel remaining equals
Northstar Explorer 435/438 Installation and Operation Manual14
The Too shallo w, Too De ep and Low
battery alarms automatically re-enable when
the value moves outside the alarm trigger setting.
The Temp erature alarm automatically
re-enables when the temperature is more than
0.45°F (0.25°C) above or below the alarm trigger
setting.
The Temperature rate alarm automatically
re-enables when the rate of temperature change
falls below the trigger setting by more than 0.2°F
(0.1°C) per minute.
Flashing Light a nd/or External
Beeper (E xplorer 438 only)
If a secondary alarm indicator is required, a flashing
light and/or external beeper can be installed. These
can be positioned anywhere suitable on the boat.
See section 6- 4 Wiring options.
or MENU to acknowledge the alarm, stop
Page 15
3-7 Setup > Units
Press MENU twice to display the Setup menu,
then select Units:
The default units
are shown in this
example.
Distance
Select from:
• nm (nautical miles)
• mi (miles)
Speed
Select from:
• kn (knots)
• mph (miles per hour)
• kph (kilometres per hour)
• km (kilometres)
3-8 Setup > Comms (E xplorer 438 only)
Use this feature when the Explorer 438 is
connected to other Northstar instruments or any
NMEA compatible instrument.
Press MENU twice to display the Setup menu,
then select Com ms:
3-9 Setup > Calibrate
Press MENU twice to display the Setup menu,
then select Calibrate:
The fuel options can
be calibrated only
when the optional
single or twin engine
kit is installed on
petrol/gasoline
engines.
Speed
be required because different hull shapes have
different flow characteristics.
Obtain an accurate measurement of the boat's
speed from a GPS receiver; or by following
Calibration may
Northstar Explorer 435/438 Installation and Operation Manual 15
Depth
Select from:
• ft (feet)
• m (metres)
• fa (fathoms)
Fuel
Select from:
• Litres
• USGal (US gallons)
• ImpGal (Imperial Gallons)
Tem per atu re
Select either:
• °F (Fahrenheit)
• °C (Celsius)
NMEA
NMEA is generally used with third party
instruments. Select On to transmit NMEA
sentences (see Appendix A - Specifications).
Otherwise, select Off.
NMEA data
Use this to specify which NMEA sentences will be
transmitted (see Appendix A - Specifications and
section 5-6 Data display, for information about
how to display NMEA data).
another boat travelling at a known speed; or by
making a timed run over a known distance.
Note: for accurate calibration:
• The speed from a GPS receiver should be
greater than 5 knots.
• The speed from another paddlewheel
transducer should be between 5 and 20
knots.
• Best results are achieved in calm conditions
where there is minimal current (best at high
or low tide).
Use the cursor ke ys to display the speed readou t box,
then increase o r decrease the readout to match the
independ ent speed value.
Page 16
Tem per atu re
The factory settings should be sufficiently accurate
for normal usage. To calibrate the temperature
readout, first measure the water temperature with a
thermometer known to be accurate.
Use the cursor keys to display the temperature
readout box, then increase or decrease the
value to match the measured temperature. The
temperature can be set from 32° to 99.9°F (0° to
37.7°C) with a resolution of 0.1° unit.
To change the units between °F (Fahrenheit) or °C
(Celsius), see section 3-7 Setup > Units.
Fuel
Calibrating the fuel usage can improve the
accuracy of fuel measurements.
Twin engine installations require each fuel
transducer to be calibrated. This can be done
at the same time with two por table tanks or at
different times using one portable tank.
Calibrating the fuel transducer(s) requires accurate
measurement of the fuel consumption. This is best
done using a small portable tank. At least 4 gallons
(15 litres) of fuel should be used to ensure an
accurate calibration.
It is often very difficult to fill underfloor tanks to the
same level twice due to air pockets, so the more
fuel used, the more accurate the calibration.
To calibrate the fuel transducer(s), perform the
following steps:
1. Record the level of the fuel in the tank(s).
2. Connect the portable tank(s) to the engine
through the fuel transducer(s).
3. Run the engine at normal cruising speed
until at least 4 gallons (15 litres) of fuel has
been used per engine.
4. Check the actual amount of fuel used per
engine by refilling the por table tank(s) to the
original level and noting the reading(s) from
the fuel dispenser’s gauge.
5. Select Fuel. Use
reading to match that on the fuel dispenser’s
gauge.
6. Press
when the reading is correct.
or
to change the
Note: If the fuel calibration opti ons appear to give
erroneous readings af ter a while, first check that the
fuel sensor has been installe d correctly according to
the installation instructions supplied with it, then see
Appendix B - Troubleshooting .
Keel Off set
Keel offset is a depth correction representing the
vertical distance between the depth transducer and
the location from which the depth is to be measured.
Enter a positive keel offset value when the
transducer is located below the water surface but
the total depth is required.
Enter a negative keel offset value when the
depth below the deepest part of the boat is
required (such as the keel, the rudder or the
propeller) and the transducer is located closer to
the water surface.
Use the cursor keys to selec t Keel offset,
then press
Use the
to display the Keel offset box.
or cursor keys to adjust the value.
Water surface
Depth of transducer
Tra nsd uce r
Note: Boat illustrated uses a through hull transducer
Positive
value
Negative
value
4 Using the Explorer 435 and Explorer 438
This section explains how to interpret the sonar
displays and how fish are detected and displayed.
It also describes Gain and Range and shows
4-1 Interpreting the d isplay
The sonar displays do not show a fixed distance
travelled by the boat; rather, they display a
history, showing what has passed below the boat
during a certain period of time.
The histor y of the sonar signal displayed depends
Northstar Explorer 435/438 Installation and Operation Manual16
examples of some of the different sonar displays.
Also see section 1-2 How the Explorer 435 and
Explorer 438 works.
the depth of the water and the scroll speed
setting.
In shallow water, the echoes have a short distance
to travel between the bottom and the boat. In
deep water, the history moves across the display
Page 17
more slowly because the echoes take longer to
travel between the bottom and the boat. For
example, when the scroll speed is set to Fast,
at depths over 600 ft (180 m) it takes about 2
minutes for each ver tical line of pixels to move
across the display, whereas at 20 ft (6 m) it takes
only about 25 seconds.
The scroll speed can be set by the user to display
either a longer history with less fish information
or a shorter history with more fish details. See
section 3-2 Setup > Sonar.
If the boat is anchored, the echoes all come from
the same area of bottom. This produces a flat
bottom trace on the display.
The screen shot shows a typical sonar display
with the Fish symbols turned Off.
Single fish
Large school
of fish
Small school
of fish
Bottom
Strength of echoes
The colors indicate dif ferences in the strength of
the echo. The strength varies with several factors,
such as the:
• Size of the fish, school of fish or other object.
• Depth of the fish or object.
• Location of the fish or objec t. (The area
covered by the ultrasonic pulse is a rough
cone shape and the echoes are strongest in
the middle.)
• Clarity of water. Particles or air in the water
reduce the strength of the echo.
• Composition or densit y of the object or
bottom.
Note: Planing hulls at speed produce air
bubbles and turbulent water that bombard the
transducer. The resulting ultrasonic noise may
be picked up by the transducer and obscure the
real echoes.
Kelp / Weed
Soft bottoms
such as mud,
weed and
sand show as
narrow bands
Hard bottoms
such as rock
or coral show
as wide bands
Bottom typ es
Mud, weed and sandy bot toms tend to weaken
and scatter the sonar pulse, resulting in a weak
echo. Hard, rocky or coral bottoms reflect the
pulse, resulting in a strong echo. See section 5-3
Sonar Bottom display.
Frequency a nd cone width
The pulse generated by the E xplorer 435 and
Explorer 438 transducer travels down through the
water, spreading out wards to form a rough cone
shape. Inside the cone, the return signals are the
strongest. The cone width is dependent upon
the transducer design and the frequency of the
pulse: with Northstar’s transom mount supplied,
it is about 15°. The chart shows how the cone
width varies over depth for each frequency used.
Figures are approximate.
Northstar Explorer 435/438 Installation and Operation Manual 17
Depth 200 kHz
0
50
100
150
200
250
15°
13
27
40
54
67
Page 18
Shadows
Shadows are created around areas where the ultrasonic beam cannot ‘see’. These areas include hollows
on the bottom or beside rocks and ledges, where the strong echoes returned of f the rocks obscure the
weak echoes of the fish and may also create a double bottom trace. See following for an example of the
sonar display in such an environment. A double bottom trace is shown on the display.
Example of shadows
fish is visible on the display
fish is hidden by the strong echoes off the
bottom and is not shown on the display
fish is visible on the display
Northstar fishfinders display the most recent events on the right of the screen.
Moving boat
1 minute ago
30 seconds ago
Sonar display of same area
Now
When the fish symbol
option is on, any echo
returned that fits
the profile of a fish is
displayed on the screen
with a fish symbol.
Northstar Explorer 435/438 Installation and Operation Manual18
Page 19
Stationary boat
1 minute ago Now
When a boat is stationary, all bottom echoes will come from the same
small area of bottom. This will produce a flat bottom trace on the
screen.
The appearance of the Sonar and Zoom screens can be
changed to suit individual preferences.
Note: Times indicated are for illustration only.
4-2 Fish detection a nd display
Where to find f ish
Underwater features like reefs, wrecks and rocky
outcrops attract fish. Use the sonar to find these
features, then look for fish by passing over the
feature slowly several times using the Zoom
display (see section 5-2 Sonar Zoom display). If
there is a current, the fish will of ten be found
downstream of the feature.
When fishing with the Exp lorer 435 and Explorer
438 with the Fish symbols Off, a weak fuzzy band
may appear between the bottom trace and
surface.
This might indicate a thermocline - a
rapid change in water temperature, such as the
edge of a warm or cold current. The temperature
difference can form a barrier which the fish
may not swim through. In fresh water, fish often
collect around a thermocline.
Fish sy mbols
The fish symbol can be customized or switched
off altogether so that the echoes are not
converted to fish symbols on the display. See
section 3-2 Setup > Sonar. The differences
between Fish symbol On and Off are:
Fish symbols On
Using Northstar’s SBN sonar technology the
fishfinder analyses all echoes and eliminates most
false signals and clutter so that remaining targets
are most likely fish. Depending on the strength of
Northstar Explorer 435/438 Installation and Operation Manual 19
the remaining
echoes,
they are
displayed as
either small,
medium or
large fish
symbols
- with or
without
depth. While
the SBN
processing
is very
sophisticated
it is not
foolproof - there will be times when the fishfinder
will not be able to differentiate between large
air bubbles, rubbish containing air, fishing floats
etc. and fish.
The following picture shows the Sonar display with
the Fish symbol: On + depth:
Fish symbol Off
For experienced users this always provides the
best information as every echo is displayed,
whether it is sur face clutter, a thermocline or a
fish.
The picture in section 4-1 Interpreting the display,
shows the Sonar display with the Fish symbols
Off. The fish appear as arches.
Time
Page 20
Fish a rches
In good conditions and with Fish symbols Off, a
fish passing through the cone-shaped ultrasonic
pulse is displayed as a fish arch.
A fish arch occurs when a fish enters the weak
edge of the sonar cone, generating a weak echo
that is displayed as the first pixel of the fish arch.
As the fish moves closer to the middle of the cone,
the distance between the transducer and the fish
reduces and the echo is displayed at progressively
shallower depths, producing the start of an arch.
When the fish passes directly beneath the middle of
the cone, the echo becomes strongest and thickest.
As the fish passes out of the middle of the cone the
reverse happens with a progressively weaker and
deeper echo.
There are many reasons why fish arches may not
be seen. For e xample:
• Poor transducer installation (see Tran som
4-3 Gain
Gain (sensitivity) controls the amount of detail
displayed on the Explorer 435 and Explorer 438.
Understanding how to set suitable Gain settings
is important for optimum performance.
The Northstar fishfinder has two gain modes,
Auto Gain and Manual Gain. Normally the
best results are obtained in Manual Gain, but
practice and experience are required to obtain
the optimum settings for different conditions.
Therefore, the use of Auto Gain is strongly
recommended when learning to use the
fishfinder or when travelling at speed.
• In Auto Gain, the gain adjusts automatically to
compensate for water depth and clarity.
• In Manual Gain, the gain can be adjusted by
the user to compensate for water depth and
clarity.
High Gain set tings may amplify the normal
background noise until it appears as random
pixels.
Changing b etween Auto and Man ual
To change between Auto Gain and Manual Gain:
1. From any Sonar display, press
2. Use the
cursor key to select Auto or
Manual.
.
Adjusting Gain settings
1. From any Sonar display, press .
2. Use the
or cursor keys to change the gain.
Northstar Explorer 435/438 Installation and Operation Manual20
Transducers Installation Guide).
• If the boat is anchored then fish will tend to
show on the display as horizontal lines as they
swim into and out of the transducer sonar
beam. Slow speeds in deeper water give the
best fish arch returns.
• Range is important. It will be much easier to
see fish arches when using zoom mode to
concentrate on a particular section of water,
rather than just displaying everything from
the surface to the bottom. Zooming increases
screen resolution up to 100 times.
• It is difficult to get fish arches in shallow water
as the transducer sonar beam is very narrow
near the surface and fish do not stay within
the beam long enough to display an arch.
Several fish in shallow water tend to display as
randomly stacked blocks of pixels.
• Wave motion may result in distorted fish arches.
Note: The Gain mode
automatically changes to
Manual Gain if the gain
setting is adjusted by
the user.
Obtaini ng the
best results
To obtain the best
detection capability for
both fish and bottom
we recommend the user adjusts the gain in the
A-Scope display until the threshold line is just to
the right of the unwanted noise:
Gain
Threshold
line
Unwanted
signal
Gain line
Page 21
4-4 Range
Range is the ver tical depth displayed on the
Explorer 435 and Explorer 438.
The Northstar fishfinder has two range modes,
Auto Range and Manual Range:
• In Auto Range, the fishfinder adjusts the
depth range automatically so the bottom is
always shown in the lower part of the display.
The use of Auto Range is recommended for
normal conditions.
• In Manual Range, the fishfinder shows only
a selected depth range. In areas of rapidly
changing bot tom depth, such as the sea floor
around pinnacles, it can be useful to prevent
the display from rescaling to always show
the bottom. If the bottom is deeper than the
specified depth range, it will not be shown
on the display.
5 The Displays
Press MENU once to show the Display menu,
then selec t a particular display using the or
cursor keys then press to confirm. (Section 2
Basic Operation, describes how to use the keys in
more detail.)
The Display me nu
Full screen display of Sonar histor y (section 5-1)
Split display with Sonar and zoomed section (section 5-2)
Bottom trace displayed as f lat line in zoomed sec tion (section 5-3)
Split display with Sonar and echo strength (section 5-4)
Fuel dat a (sec tion 5-5)
Water temperature, depth history and other boat data (sec tion 5- 6)
See below.
Changing th e Range Mode
To change between Auto Range and Manual
Range, hold the + or -. The Range mode is
displayed at the bottom of the screen.
Press the + or - key to change to increase or
decrease the range to the desired depth. Values
can be set between 10 ft (3 m) to 600 ft (180 m).
Zoom Range and Zoo m Offset
On the Sonar Zoom and Sonar Bottom displays, a
vertical bar is shown on the far right of the display.
This is the zoom bar. The zoom bar shows the zoom
range; that is, the area that is magnified.
Use the
or cursor keys to adjust the
zoom range.
Use the
or cursor keys to adjust the
zoom offset.
The Display menu is summarized here and each
display is shown in the following sec tions.
Most displays have an Options menu so that
relevant features can be changed quickly.
Split Ratio
Use this to change the split ratio bet ween the zoom and the sonar history sections displayed. The
default split ratio is 50% .
1. Highlight Split Ratio and press
A left arrow and right arrow appear on either side of the divider line.
2. Use the
Hint: Press
selected display. Use this to switch between two frequently used displays.
Refer to Section 3-2 Setup > Sonar, for information about customizing features on the sonar displays.
or cursor keys to adjust
to return to the last sonar display used. Press MENU then to return to the previously
Northstar Explorer 435/438 Installation and Operation Manual 21
.
Page 22
5-1 Sonar display
To show the Sonar display highlight Sonar and
press :
Data header, set up to show
the water temperature, battery
voltage (See section 3-2 Setup
> Sonar)
This display scrolls from right (most recent
echoes) to left (oldest echoes). (see section 3-2
Setup > Sonar).
Surface
Depth (medium size digits)
Color bar
5-2 Sonar Zoom displa y
To show the Sonar Zoom display, highlight
Sonar Zoom and press :
Sonar history
Zoom bar
Zoom section
Divider line
5-3 Sonar Bottom d isplay
To show the Sonar Bottom display, highlight
Sonar Bottom and press .
This shows a split display, with the sonar history
on the right side and the zoom sec tion on the
left. The bottom signal is shown as a flat trace in
the centre of the zoom section.
Showing the bottom as a flat trace can make it
easy to compare the echo strengths shown in the
Fish symbols with depth
Bottom
Range
The split display shows the sonar history on the
right side and the zoom section on the left.
The zoom bar on the far right shows the area that
is magnified in the zoom sec tion. See section 4-4
Range, for information about adjusting the Zoom
Range and Zoom Offset.
bottom signals. This can help to identify the type
of bottom and objects close to the bot tom.
The zoom bar can only indicate the zoom range.
It cannot indicate the zoom of fset as this changes
for each sounding displayed on the display. The
zoom bar is fixed in the middle of the display.
See section 4-4 Range, for information about
adjusting the Zoom Range and Zoom Offset.
Northstar Explorer 435/438 Installation and Operation Manual22
Page 23
5-4 Sonar A-Scope di splay
To show the A-Scope display, select Sonar
A-Scope and press . Use this to analyse the sonar
data in detail and optimize the Gain settings.
Divider line
between
sonar history
and A-Scope
Gain setting
(strongest
echo for
display)
Gain threshold
(weakest echo
for display)
5-5 Fuel display ( Explorer 438 only)
To show the Fuel display, select Fuel and press
(See section 3-3 Setup > Fuel for information about
setting up the fuel values. If the number of engines is
set to 0, the fuel features are turned off.)
Used shows total fuel used since this was last
reset with the Cle ar Use d command.
The user can define the level of the weakest and
strongest echoes to be shown on the sonar displays,
by using the Gain setting. See sec tion 4 -3 Gain, for
more information.
The strength of an echo at a par ticular depth
is shown by the length of the horizontal line at
that depth. A strong echo produces a long line
whereas a weak echo produces a short line.
Fish recogniti on
The echo strengths shown on the A-Scope can
be useful in recognising the type of fish. Different
species of fish have different sizes and shapes
of swim bladders. The air in the swim bladder
reflec ts the ultrasonic pulse, so the strength of
the echo varies between fish species according to
the size and shape of the swim bladder.
When fishing among a school of fish and
catching them, note the fish species and the
strength of the echo that it returns on the
A-Scope. Then, when that particular echo is seen
at future times on the fishfinder, it is likely to be
the same fish species.
Remaining shows the amount of fuel
remaining in the tank(s).
Flow shows the fuel consumption per hour.
For twin engine installations, the fuel f low for
each engine is shown separately. This is useful
for checking that both engines are under the
same load.
Economy is the distance travelled per unit of fuel
used. The fishfinder calculates this from the boat
speed and fuel used. The bigger this number, the
better the fuel economy. Adjust the throttle and
trim to achieve the best fuel economy. Note that
the Explorer 438 uses a paddlewheel transducer
to measure speed, used to calculate the fuel
economy. Therefore, calibration of the boat
speed measurement is essential for an accurate
.
fuel economy reading. See section 3- 8 Setup >
Calibrate.
Northstar Explorer 435/438 Installation and Operation Manual 23
Page 24
5-6 Data di splay
To show the Data display, select Data and press . The data display
shows a graph of the water temperature and depth over time and oth er
selected data items.
The graph is useful for locating warm and cold spots in the water.
Refer to section 3-4 Setup > Data to change the displayed data items
and temperature graph time base. To change units, refer to section 3-7
Setup > Units.
time base
(Select from 5 minutes to 2 hours)
6 Installation and Maintenance
Correct installation is critical to the performance of the Explorer 435 and Explorer 438. There are two
components to install, the display unit and the transducer. It is vital to read the entire installation section
of this manual before attempting to install the components.
6-1 What comes with th is product?
Standard configuration:
• Explorer 435 or Explorer 438 display unit
• Power cable*
• Mounting bracket (screws included)
• Warrant y registration card
• This manual
• Sun cover for display unit
• Flush mounting kit*
• Transom transducer (includes cable kit and screws)
• Transom Mount Transducer Installation Manual.
*
denotes Explorer 438 only.
Display unit
6-2 Options and Acce ssories
• Explorer 500 series chartplot ters
• Through hull depth transducer
• Through hull speed/temperature transducer*
• Fuel flow kit (single or twin engine)*
• Replacement paddle wheel*
• Carry bag
• Explorer R310 (see section 6-5 Systems of several instruments).
Please consult your Northstar dealer for more information.
* denotes Explorer 438 only
6-3 Mounting an d removing the display un it
There are two mounting arrangements:
• Flush mounting requires a solid panel with
access behind for wiring and mounting
screws. Af ter flush mounting, the Explorer 435
Northstar Explorer 435/438 Installation and Operation Manual24
and Explorer 438 cannot be tilted or moved
after installation to reduce any unwanted
glare or reflections. Carefully select the best
viewing position before installation. This
would generally be in a shaded area.
Transom transducer
Explorer 550
chartplotter
Mounting bracket
Screws
Power cable
Fuel flow kit
Page 25
• Bracket mounting requires a panel for
mounting the bracket. Ensure that the panel
is not likely to deform and is not subject to
excessive vibration. The bracket can be tilted
and rotated so the Explorer 435 and Explorer
438 can be removed af ter each use.
Select a position where the display unit will be:
• At l east 4" (100 mm) away from the co mpass.
• At least 12" (300 mm) away from any radio
transmitter.
• At least 4 ft (1.2 m) away from any antenna.
• Easy to read by the helmsman and crew while
underway.
• Protected from physical damage during
rough sea passages.
• Easy to access the 12 V DC power source.
• Convenient to route the transducer cables.
Flush Mountin g
1. Cut a hole in the bulkhead for the display unit
using the flush mount template.
2. Drill four holes for the mounting studs using
the flush mount template.
6-4 Wiring O ptions
The power/data cable contains 5 wires:
Wire Function
Black Ground (power negative)
White* NMEA out
Red Positive power in, 12 V DC
Yellow Auto power in (connect to red wire.
Positive power in, to enable Auto power).
Green* External beeper or light out, switched
to ground, 30 V DC 200 mA maximum.
Note: The cable shield is connec ted to Pin 1 (black
wire) and does not nee d to be grounded. * Denotes
Explorer 438 only.
CAUTION
1 Amp fuses must be positioned where shown
in the wiring diagrams.
3. Screw the four studs into the brass inserts in
the back of the display unit.
4. Sit the display unit in place and fit the
washers and nuts to the studs.
Bracket Mounting
1. Fix the mounting bracket onto the boat using the
three stainless steel screws. Do not overtighten
the screws, as the bracket may not rotate.
2. Push the display unit onto the mounting
bracket and tighten it firmly using the knob
on the mounting bracket.
3. At tach the cables.
Removing the d isplay unit
The display unit can be removed af ter each
use for protection against the environment or
security reasons.
When removing the display unit, ensure that
the plugs lef t in the boat are not exposed to the
elements. Push the attached dust covers over the
exposed ends of the plugs. Keep the display unit
in a dry clean place such as the optional Northstar
carry bag.
Six wiring options are described in this section:
• Basic wiring. This does not start the
fishfinder automatically when the boat
ignition is switched on and it disables the
engine hours counter.
• Auto power wiring. This must be used for
the engine hours and fuel computer options.
• Secondary Alarm wiring
• NMEA wiring
• Single engine fuel wiring
• Twin engine fuel wiring
Note: If a wire color is not specifical ly mentioned, it is
not used in that wiring option.
Section 6-5 Systems of several instruments,
describes NMEA and NavBus.
Basic wiring
This requires the Explorer 435 and Explorer 438 to
be powered on manually with the key.
Black wire: Connect this to the negative battery
terminal.
Northstar Explorer 435/438 Installation and Operation Manual 25
Red wire: Connect this to the positive battery
terminal af ter the main switch. Fit a 1 Amp fuse
as shown.
Yellow wire: Connect this to the black wire. This
disables the engine hours counter.
Power on the fishfinder manually whenever the
main switch is on.
Page 26
Basic wiring
Fuse
Main
switch
12 V DC
Red
Yellow
Black
NMEA wiring Option (Expl orer 438 only)
White Wire: Use this, if desired, to connect
the fishfinder to other NMEA instruments such
as Northstar’s Explorer R310. (See section 6-5
Systems of several instruments.)
Secondary alarm wiring option
(Explo rer 438 only)
Green Wire: Use this to connec t a secondar y
alarm indicator such as a flashing light or external
beeper with a built-in drive circuit. See the Auto
power wiring diagram.
If the external beeper or light requires more than
200 mA total, fit a relay. Consult your Northstar
dealer for more advice.
Fuel kit wiring (E xplorer 438 only)
See the Fuel Kit Installa tion Guide for information
about the fuel transducer cable.
Wire the power cable for Auto power (as
described in this section) to make sure the fuel
counter star ts as soon as the engine starts.
For twin engine installation, a T-connec tor needs
to be installed on the fuel transducer cable.
Auto power op tion
Black wire: Connect this to the negative
battery terminal.
Red wire: Connect this to the positive battery
terminal af ter the main switch. Fit a 1 Amp fuse
as shown.
Yellow wire: To enable the engine hours counter
and fuel counter; and to star t the fishfinder
automatically when the ignition is turned on,
connect the yellow wire to the ignition sys tem
through a 1 Amp fuse.
Note: The fishfinder cannot be tur ned off while the
ignition is on.
Auto power op tion
To ignition system
Ignition
switch
Main
switch
Fuse
Fuse
External Beeper
or Light
12 V DC
White (NMEA out)
Yellow
Red
Green
Black
Through hull tran sducers
Through hull transducers are supplied wth ‘Y’ adapter cable for
connection of both transducers into top socket with blue nut.
Speed/Temperature through hull transducer
Through hull depth transducer
6-5 Systems of several i nstruments
Several Nor thstar instruments can be connected
together to share data.
NMEA
NMEA is an industry standard for marine
instrument connections. Data sent by one
instrument over an NMEA line can be read and
Northstar Explorer 435/438 Installation and Operation Manual26
displayed by another instrument that accepts
NMEA 0183 Version 2. It requires dedicated
connections between instruments.
Please contact your Northstar dealer for
information on Northstar’s full range of NMEA
enabled instruments and connection options.
8 pin
phono
Page 27
Explo rer R310: Repeater
for depth, speed, water
temperature and battery
voltage. Accepts NavBus or
NMEA data inputs from other
instruments.
Explorer D210:
Depth Repeater
6-6 Clea ning and maintena nce
Clean the screen only with a damp cloth and mild
detergent when dirty or covered in sea salt. Avoid
abrasive cleaners, petrol or other solvents.
Cover or remove a transom-mounted transducer
when repainting the hull. If painting over a
through hull transducer with antifouling paint, use
only one coat of paint. Remove the previous coat
of antifouling paint by sanding it lightly.To optimize
performance, avoid walk ing on or jamming cables
Appendix A - Specifications
Depth range
• 2 ft (0.6 m) to 600 ft (180 m).
Display type
• TFT Color.
• Screen resolution 320 high x 240 wide (pixels).
• LED multi-level backlighting.
Supply voltage
• 10 to 16 V DC.
Supply current at 13.8 V
• 300 mA min - no back lighting.
• 400 mA max - full backlighting.
Output power
• Variable, up to 200 W RMS.
Operating temperature
• 32° to 122°F (0° to 50°C)
Transom transducer cable length
• Explorer 435 33 ft (10 m).
• Explorer 438 26 ft (8 m).
Typical depth acquisition time from startup
• 2 seconds at 100 ft (30 m).
Receiver sensitivity
• Better than 10 micro volts RMS.
• Dynamic range 4.0 million to 1 (120 dB).
Temperature measurement range
• 32° to 99.9°F (0° to 37.7°C)
Resolution of 0.1° unit.
Transducer frequency
• 200 kHz.
Northstar Explorer 435/438 Installation and Operation Manual 27
Explorer 550:
Color GPS
Chartplotter
with worldwide
coverage
and connec tors. Keep the transducer free of weed,
paint and debr is.
blast on a spe ed sensor paddlewhe el as it may
Do not use a high pre ssure water
damage the bearings.
When not in use, the Explorer 435 or Explorer 438
can be removed f rom the installation bracket and
stored in the No rthstar carry b ag, or left on the
installatio n bracket and securely covered wi th the
sun cover.
Speed range
• 1 to 50 kn (57.5 mph, 96.6 kph).
Standards Compliance
• EMC:USA FCC Part 15 Class B.
Europe (CE) EN50081-1 and EN50082-1
New Zealand and Australia (C Tick)
AS-NZS 3548.
· Environment: IPx6, IPx7.
NMEA Output (Explorer 438 only)
NMEA 0183 (Ver 2.0) 4800 baud is a standard
for interfacing marine electronic devices. T he
Northstar fishfinder can output the following
sentences:
• DBT (Depth Below Transducer)
• DPT (Depth and Keel offset)
• MTW (Water temperature)
• XDR (Battery voltage and fuel flow).
• VHW (Speed)
Fuel Computer (Explorer 438 only)
(optional fuel transducer(s) required)
• Outboard carburetted two stroke and EFI
petrol/gasoline engines: 30 to 300 hp.
• Outboard four stroke petrol/gasoline engines:
90 to 300 hp.
• Inboard p etrol/gasoline engines : 50 to 300 hp.
• Minimum f low rate: 1.3 U.S. gallons per hour
(5 litres per hour).
• Maximum flow rate: 34 U.S. gallons per hour
(130 litres per hour).
Page 28
5.0" (126.0 mm)
5.7" (143.5 mm)
5.0" (126.0 mm)
Explorer 435: 89 mm (3.5")
Explorer 438: 97 mm (3.
1.1" (27.9 mm)
1.2" (30.5 mm)
8")
Explorer 435 and 438
Appendix B - Troubleshooting
This troubleshooting guide is written with the
assumption that the user has read and understood
the relevant sections in this manual.
It is possible in many cases to solve difficulties
without having to send the display unit back to
the manufacturer for repair. Please follow this
troubleshooting section before contacting the
nearest Nor thstar dealer.
There are no user serviceable parts. Specialized
methods and testing equipment are required
to ensure that the display unit is reassembled
correctly and is waterproof. Users who ser vice the
product themselves will void the warranty.
Repairs to the product may only be carried out
by a service centre approved by Northstar. If the
product must be sent into a ser vice centre for
repair, it is essential to send in the transducer(s) at
the same time.
More information can be found on our Website:
www.Northstarnav.com.
1. The fishfinder won’t turn on:
a) The Explorer 435 and Explorer 438 are
designed to operate on a 12 volt battery
system, where the voltage may vary from
10 to 16.5 volts. If an excessive voltage is
supplied, a resettable fuse will be tripped,
turning the display unit off.
b) Check that the p ower cable connector at the
back of the disp lay unit is securely plugged in
and the collar is l ocked in place. The collar must
be secure fo r watertight connec tion.
Northstar Explorer 435/438 Installation and Operation Manual28
3.5" (88.5 mm)
c) Measure the batter y voltage while the bat tery
is under load - turn on some lights, radio or
other elec trical equipment connected to the
battery. If the voltage is less than 10 volts:
- the batter y terminals or wiring on the
terminals may be corroded.
- the batter y may not be charging correctly or
may need replacing.
d) Inspect the power cable from end to end for
damage such as cuts, breaks, squashed or
trapped sections.
e) Ensure that the red wire is connected to the
positive bat tery terminal and the black wire to
the negative battery terminal. If wired for the
Auto Power option, ensure the yellow wire is
connected to the ignition circuit. Also check
the boat’s main switch circuit (see section 6-5
Wiring options).
f) Check for corrosion on the power cable
connector and clean or replace if required.
g) Check fuses that are placed in line with the
power cable. A fuse can be blown despite
appearing to be good or the fuse may be
corroded. Test the fuse or replace it with a
fuse known to be good.
2. T he fishfinder won’t turn off:
The fishfinder may have been wired for Auto
power. In this case, the fishfinder cannot be
turned of f while the ignition power is on.
(See Auto power wiring in section 6-4 Wiring
options.)
Page 29
3. The fishfinder operates erratically:
a) Check that the transducer does not have
debris (e.g. weed, plastic bag) caught
around it.
b) The transducer may have been damaged
during launching, running aground or while
underway with debris etc. If the transducer
has been impacted, it may have been kicked
up on the bracket. If it is not physically
damaged, reset the transducer back to its
original position. (See the Tr anso m Tra nsdu cer
Installation Guide.)
c) When the transducer is less that 2 ft (0.6 m)
from the bot tom, the depth readings may
become inconsistent and erratic.
d) Manual Gain may be set too low, which may
cause weak bottom echo or no fish signals. If in
Manual Gain, tr y increasing the Gain.
e) Ensure the back of the bottom surface of the
transducer is slightly lower than the front and
the front is as deep in the water as possible
in order to minimize the generation of
bubbles through cavitation. (See the Tr ans om
Transducers Installation Guide.)
f) Check the transducer and power cable
connectors at the back of the display unit
are securely plugged in and the collars are
locked in place. The collars must be secure for
watertight connection.
g) Insp ect the power cable from end to end for
damage such as cuts, breaks, squashed or
trapped sections.
h) Ensure there is not another fishfinder or
depth sounder turned on, which may
interfere with this fishfinder.
i) Electrical noise from the boat’s engine or
an accessor y may be interfering with the
transducer(s) and/or the Northstar fishfinder.
This may cause the fishfinder to automatically
decrease the Gain unless using Manual Gain.
The fishfinder thus eliminates weaker signals
such as fish or even the bottom from the
display. This may be checked by switching
off other instruments, accessories (e.g. bilge
pump) and the motor until the offending
device is located. To stop problems from
electrical noise, try:
- re-routing the power and transducer cable (s)
away from the boat’s other electrical wiring.
- routin g the display unit’s power ca ble directly to
the batter y with an in-line f use.
Northstar Explorer 435/438 Installation and Operation Manual 29
4. Bottom is not displayed:
a) The fishfinder may have Manual Range
selected and the depth may be outside the
range value selected. Either change the
fishfinder to Auto Range or select another
depth range (see section 4-4 Range).
b) The depth may be outside the fishfinder’s
range. While in Auto Range, the display unit will
display “--.-” to indicate that there is no bottom
detected. A display of the bottom should
reappear when in shallower water.
5. The bottom is displayed too far up
the screen:
The fishfinder may have Manual Range
selected and the selected Range value is
too high for the depth. Either change the
fishfinder to Auto Range or select another
depth range (see section 4-4 Range).
6. Bottom echo disappears or erratic digital
reading while the boat is moving:
a) Ensure the back of the bottom surface of
the transducer is slightly lower than the
front and the front is as deep in the water as
possible in order to minimise the generation
of bubbles through cavitation. (See the
Tran som Trans duce rs I nsta lla tio n Gu ide, for
more information.)
b) The transducer may be in turbulent water.
Air bubbles in the water disrupt the echoes
returned, interfering with the fishfinder’s
ability to find the bottom or other targets.
This often happens when the boat is
reversed. The transducer must be mounted
in a smooth flow of water in order for the
fishfinder to work at all boat speeds.
c) Elec trical noise from the boat’s motor
can interfere with the fishfinder. Try some
suppression spark plugs.
7. If the fishfinder beeps when turned on but
nothing is displayed:
The fishfinder may be operating, but the
backlight settings may have been set too low.
See section 2 Basic Operation, to adjust the
fishfinder backlight. (Press
twice)
8. The wrong language is displayed:
See section 3-1 Setup > System.
Page 30
9. Fuel used or remaining seem inaccurate:
a) If the engine is run while the fishfinder is
powered of f, the fishfinder does not record
the amount of fuel used during that engine
run. Consequently, the Fuel remaining
value will be higher than the actual amount
of fuel remaining in the tank.
To avoid this problem, use the Auto Power
Wiring option described in section 6-4 Wiring
options. This ensures that the fishfinder powers
on automatically whenever the boat’s ignition
is switched on.
b) In rough seas, fuel may surge back and forth
through the fuel transducer, resulting in
incorrect readings. Try installing a one-way
valve between the fuel transducer and the
fuel tank.
c) The Set remaining fuel value must be
reset after every refuelling (see section 3-3
Setup > Fuel).
d) The fuel tank may not refill to the same capacity
each time due to air pockets. This is particularly
noticable with underfloor tanks.
e) Fuel transducers wear out over time and
should be replaced after every 5000 litres of
fuel.
10. Flow indicates no fuel or low fuel:
a) Check that the number of engines is set to 1.
See section 3-3 Setup > Fuel.
b) Check that the fuel cable connectors are
securely plugged in and the collar is locked
in place. The collar must be locked in place to
give a watertight connection.
c) A fuel transducer may be clogged. If so,
remove the transducer from the fuel line
and gently blow through it in the opposite
direction to the fuel flow.
A fuel filter between the fuel transducer and
the fuel tank must be installed as per the
fuel installation guide. Failure to do so will
void the warranty.
d) Insp ect the fuel cable from end to end for
damage such as cuts, breaks, trapped or
squashed sections.
e) Check that the fuel filter is clean.
11. A twin engine installation shows only one
flow rate:
a) Check that the number of engines is set to
2. See section 3-3 Setup > Fuel.
12. Erratic Fuel Flow readings:
a) The fuel flow transducer may have been
mounted too close to the fuel pump or may
be subject to excessive vibration. Refer to the
installation instructions supplied with the fuel
transducer.
b) Check for leaks in the fuel line or in the fuel
pickup in the tank.
c) The Flow filter v alue is not suitable for the
engine. Check t hat the value is not set to zero,
then try i ncreasing the value until a stead y flow
rate is shown. Se e section 3-3 Setup > Fuel.
13. There is no reading for fuel economy:
a) The boat must be travelling through the
water to generate an Economy reading.
b) Check that the paddlewheel o n the transducer
is spinning fre ely and that the two magnet s in
the paddlewheel are still in place.
14. There is a double bottom trace displayed:
a) The boat may be in an area that generates
shadows. See section 4-1 Interpreting the
display.
b) In shallow water, the echoes may bounce.
Reduce the gain setting (see section 4-3
Gain).
c) Decrease the Range.
Northstar Explorer 435/438 Installation and Operation Manual30
Page 31
Page 32
AMERICAS
30 Sudbury Road,
Acton, MA 01720, USA
Ph: +1 978.897.6600
Ph: +1 800.628.4487
Fax: +1 978.897.7241
EUROPE
Unit 2, Ocean Quay,
Belvidere Rd, Southampton,
SO14 5QY, ENGLAND
Ph: +44 2380 339922
Fax: +44 2380 330345
AUSTRALIA
PO Box 479,
Gladesville, NSW 2111,
AUSTRALIA
Ph: +61 2 9879 9060
Fax: +61 2 9879 9009
www.northstarnav.com
NEW ZEALAND
PO Box 68 155,
Newton, Auckland
Auckland, NEW ZEALAND
Ph: +64 9 481 0500
Fax: +64 9 481 0590
Made in New Zealand
MN000598A-G
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