Garmin 128, 126 User Manual

GPS 126/128

ZOOM

Marine

Navigator

GPS 126 shown

Owner’s Manual

&

Reference

®

Software Version 2.0 or above
© 1997 GARMIN International, Inc

1200 E. 151st Street, Olathe, KS USA 66062
Tel: [phone] or 800-800-1020
Fax: [phone]
Web Site Address: www.garmin.com

GARMIN (Europe) Ltd.
Unit 5,
The Quadrangle, Abbey Park Industrial Estate,
Romsey, SO51 9AQ, U.K.
Tel: [phone]
Fax: [phone]

GARMIN (Asia) Corp.
4th Fl., No. 1., Lane 45,
Pao-Hsing Road,
Hsin Tein,
Taiwan R.O.C.
Phone: [phone]
Fax: [phone]

All rights reserved. No part of this manual may be reproduced or transmitted in any
form or by any means, electronic or manual, including photocopying and recording, for
any purpose without the express written permission of GARMIN.

Information in this document is subject to change without notice. GARMIN reserves
the right to change or improve its products and to make changes in the content without
obligation to notify any person or organization of such changes or improvements.

GARMIN, AutoLocate,TracBack, and are all trademarks of GARMIN International
and may not be used without the expressed permission of GARMIN.

January 1998 - Part #190-00151-00 Rev. A - Printed in Taiwan.

i

INTRODUCTION

GPS 126/128

OWNER’S

Packing List

MANUAL

Welcome to the easiest-to-use fixed-mount GPS on the water! The GPS
126 and GPS 128 represent GARMIN’s continuing commitment to provide
mariners with quality navigation information in a versatile, accurate, and
user-friendly design which will be useful for years to come. Due to the simi­larity between the GPS 126 and GPS 128, we have addressed both units in
one manual. This manual is organized into four sections for your conve­nience:

Introduction gives a quick overview of the manual and contains the
table of contents and glossary of navigation terms.

Getting Started introduces you to the basic features of the unit with a
quick-start orientation to the GPS 126/128. This section has been designed to
acquaint you with the unit and provide a basic working knowledge necessary
to use the unit in typical conditions.

Reference provides detailed explanations of advanced features and oper­ations in a topical format. This allows you to concentrate on a specific topic
quickly, without reading through sections of text that you may not need.

The Appendix section contains step by step instructions on how to ini­tialize the unit for first time use, installation instructions and items with mul­tiple listings, such as: map datums, time offsets, and the index.

Packing List

Before getting started with your GPS receiver, check to see that your
GARMIN GPS 126/128 package contains the following items. If you are miss­ing any parts, please contact your dealer immediately.

Standard Package:

• GPS 126/128 Unit • Mounting Bracket with knobs

• Power/Data Cable • Owner’s Manual

• Quick Reference Guide

* The GPS 128 also comes with an external antenna with 30’ cable.

See your GARMIN dealer for accessories, including our PC kit.

Thanks for choosing the GARMIN GPS 126/128. We hope it will meet all
of your navigation needs.

ii

INTRODUCTION

Caution

The GPS system is operated by the government of the United States,
which is solely responsible for its accuracy and maintenance. The system is
subject to changes which could affect the accuracy and performance of all
GPS equipment. Although the GPS 126/128 is a precision electronic
NAVigation AID (NAVAID), any NAVAID can be misused or misinterpreted
and, therefore, become unsafe.

Use the GPS 126/128 at your own risk. To reduce the risk of unsafe
operation, carefully review and understand all aspects of this Operator’s
Manual and thoroughly practice operation using the simulator mode prior to
actual use. When in actual use, carefully compare indications from the GPS
126/128 to all available navigation sources including the information from
other NAVAIDs, visual sightings, maps, etc. For safety, always resolve any dis­crepancies before continuing navigation.

NOTE: This device meets requirements for Part 15 of the FCC limits for
Class B digital devices for home or office use. It has been tested for compli­ance with all necessary FCC standards. 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
other equipment, which can be determined by turning the equipment off and
on, the user is encouraged to try and correct the interference by relocating the
equipment or connecting the equipment to a different circuit than the affected
equipment. Consult an authorized dealer or other qualified service technician
for additional help if these remedies do not correct the problem. Operation is
subject to the following conditions: (1) This device cannot cause harmful
interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation. The GPS 126/128
does not contain any user-serviceable parts. Repairs should only be made by
an authorized service center. Unauthorized repairs or modifications could
void your warranty and your authority to operate this device under Part 15
regulations.

iii

INTRODUCTION

Table of

Contents

SECTION ONE Introduction

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Navigation Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

SECTION TWO Getting Started

Keypad Usage & Data Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Primary Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Power On & Marking a Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Position Page and Map Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Going to a Waypoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Compass Page & Cancelling A GOTO . . . . . . . . . . . . . . . . . . . . . . . .12

Clearing the Map Display, Adjusting Contrast, & Power Off . . . . . . . .13

SECTION THREE Reference

Satellite Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Backlighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Position Page & User Selectable Fields . . . . . . . . . . . . . . . . . . . . . . . .16

Marking a Position & Position Averaging Function . . . . . . . . . . . .18, 19

Waypoint Pages & Managing Waypoints . . . . . . . . . . . . . . . . . . . . . . .19

TracBack Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Creating and Using Routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

Using the Compass & Highway Pages . . . . . . . . . . . . . . . . . . . . . . . .33

Map Page, Zooming, & Panning . . . . . . . . . . . . . . . . . . . . . . . . . .37, 38

Map Page & Track Log Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . .39, 40

Menu Page & Distance/Sun Calculation . . . . . . . . . . . . . . . . . . . . . . .43

System Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46

Navigation Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

Interface Setup & DGPS Interface . . . . . . . . . . . . . . . . . . . . . . . . .44, 45

Navigation Simulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

Appendix A––Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

Appendix B—Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

Appendix C—Specifications & Wiring . . . . . . . . . . . . . . . . . . . . . . . .58

Appendix D—Messages and Time Offsets . . . . . . . . . . . . . . . . . . . . . .60

Appendix E––Map Datums . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62

Appendix F––Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

1

INTRODUCTION

Glossary

The GPS 126/128 is a powerful navigation tool that can guide you any­where in the world. To better understand its operation and capabilities, it may
be helpful to review the basic terms and concepts briefly explained below.

Other navigation and GPS definitions used in the manual are defined in the
appropriate reference sections of the manual.

Almanac Data

Satellite constellation information (including location and health of satel­lites) that is transmitted to your receiver from every GPS satellite. Almanac data
must be acquired before GPS navigation can begin.

Bearing

The compass direction from your position to a destination.

Course Made Good (CMG)

The bearing from the “active from” position (your starting point) to your
present position.

Crosstrack Error (XTK)

The distance you are off a desired course in either direction.

Desired Track (DTK)

The compass course between the “from” and “to” waypoints.

Differential GPS (DGPS)

An extension of the GPS system that uses land-based radio beacons to
transmit position corrections to GPS receivers.

Estimated Time of Arrival (ETA)

The time of day of your arrival at a destination.

Estimated Time Enroute (ETE)

The time left to your destination at your present speed.

2

INTRODUCTION

Glossary

Grid

Coordinate system that projects the earth on a flat surface, using square
zones for position measurements. UTM/UPS and Maidenhead formats are grid
systems.

Ground Speed

The velocity you are traveling relative to a ground position.

Latitude

The north/south measurement of position perpendicular to the earth’s
polar axis.

Longitude

An east/west measurement of position in relation to the Prime Meridian,
an imaginary circle that passes through the north and south poles.

Navigation

The process of traveling from one place to another and knowing where
you are in relation to your desired course.

Position

An exact, unique location based on a geographic coordinate system.

Track (TRK)

The direction of movement relative to a ground position.

Universal Transverse Mercator (UTM)

A grid coordinate system that projects global sections onto a flat surface to
measure position in specific zones.

Velocity Made Good (VMG)

The speed you are traveling in the direction of the destination.

Waypoint

A specific location saved in the receiver’s memory.

3

INTRODUCTION

NORTH

“ACTIVE FROM”

WAYPOINT

NORTH

DTK

CROSSTRACK ERROR

BRG

TRK

GROUND SPEED

DISTANCE

“ACTIVE TO”

WAYPOINT

“ACTIVE LEG”

Navigation

Basics

The GPS 126/128 provides steering guidance and navi­gation information using degrees, a measurement measured
in a clockwise direction from a north reference. North is
described as 000º, east as 090º, south as 180º, and west as
270º. The diagram and compass rose below provide a graphic
illustration of the navigation terms used by the GPS 126/128.
More information on basic navigation and GPS are available
at your local library or bookstore.

4

P

J

M

Turns the unit on and off and
activates screen backlighting.

Scrolls through the main data
pages in sequence and returns
display from a submenu page
to the main page.

Captures a position and dis­plays the mark position page.

INTRODUCTION

Keypad Usage

and Data Entry

G

F

Q

B

I

H

UD

Displays the GOTO page with
the waypoint highlighted for
GOTO operation.

Confirms data entry and
activates highlighted fields
to allow data entry.

Returns the display to a previ­ous page, or restores a data
field’s previous value.

Marks your present GPS posi­tion and instantly sets a return
course while providing steer­ing guidance.

Decreases the scale of the
moving map.

Increases the scale of the
moving map.

Selects alphanumerical
characters and menu choices
and moves the field highlight
from field to field.

DATA ENTRY

The arrow keypad is
used for all data entry.
Use the

U and D

keys to select letters,
numbers, and menu
options; use the

R keys to move the cur-

sor forward or back­ward along the line.
Press
your entry.

L and

F to confirm

LR

Moves the selected character
field and moves the field
highlight from field to field.

5

INTRODUCTION

Primary Pages

Satellite Page

The Satellite Page will
allow you to monitor
satellite signal reception
and strength.

Primary Pages

Before we start the tour, let’s briefly look at the five
primary information pages used for the GPS 126/128.
To switch between pages press either the
keys (see below).

Q

or

J

J

Q

Satellite Page

The Satellite Page shows satellite positions and
signal strength. Satellite positions are displayed using
two circles and a center point. The outer circle shows
satellites on level with the horizon; the inner circle is
45º above the horizon; and the center point represents
satellites directly overhead. Knowing satellite positions
will show you the direction of any blocked signals.

The bottom of the page contains a row of signal
strength bars corresponding to each satellite being used.

Position Page

The Position Page shows you where you are, what
direction you’re heading, and how fast you’re going.

The top of the page contains a compass tape which
is a graphic representation of your heading.

Position Page

6

The graphic compass tape reflects your head-

!

ing only while you are moving.

#

Your track and speed are indicated immediately
below. Underneath are two user-selectable fields for a
variety of data. The current position is displayed in lati­tude and longitude or a user selectable grid format. A
12/24 hour clock is also provided.

Map Page

The Map Page acts as a window. It allows you to
view your position, the “path” you have traveled over,
and nearby waypoints.

A diamond icon in the center of the screen repre­sents your current position. As you move, you will see a
thin line called a track log appear along the path you

have just covered. Names of stored waypoints and
waypoint symbols can also be shown on the map.

The bottom corners of the screen always display
your current track and speed. When going to a way­point, highlighting an on-screen waypoint, or using the
panning target crosshair, the corresponding distance
and bearing are shown at the top corners of the screen.

Navigation Page

A navigation page gives you steering guidance when
going to a waypoint. The GPS 126/128 has two naviga­tion page choices: the Highway Page and the Compass
Page. The Highway Page is the default and will be
briefly explained here. The Compass Page is covered on
page 36.

The Highway Page uses a graphic highway to show
your movement in relation to your desired course. The
upper section shows bearing and distance to the way­point and your current track and speed. The middle
portion contains the actual highway. The highway indi­cates the crosstrack error, or distance and direction,
your are off-course from your waypoint. Always turn in
the direction the highway is pointing. For example, if
the highway points straight up, no turn is needed. If the
highway points right, you need to turn right until the
highway points straight up. The pointer just below the
CDI scale always points to your selected waypoint, rela­tive to the direction you are moving. The remainder of
the page contains two user-selectable fields.

Menu Page

The last primary page is the Menu Page. The Menu
Page gives you access to the GPS 126/128’s waypoint
management, route, and setup features through a list of
submenus. The Menu Page is covered on page 43.

INTRODUCTION

Primary Pages

Map Page

The Map Page shows your
progress on a moving track
plotter and gives you a
bird’s-eye-view of sur­rounding waypoints.

Highway Page

With the Highway Page,
you will get graphic steer­ing guidance when navigat­ing a route or going to a
single waypoint.

7

GETTING

STARTED

Power On &

Marking a

Position

The Welcome Page will
be shown while the unit
conducts a self test.

Getting Started Tour

Now that you are familiar with the primary pages,
it’s time to take a tour. This is a live tour and is to be
conducted with your unit installed and with the boat in
the water. The tour will take you through the receiver’s
basic features and functions as you move about on the
water and assumes that the GPS 126/128 is turned on
and initialized, (see page 52 for initialization proce­dure) and that you have not changed any of the factory
settings (units of measure, selectable fields, etc.). If
these settings have been changed, the pictures and
descriptions in this manual may not match what you
see on your screen.

Navigation Simulator

If you are not able to take the Getting Started Tour
with your boat in the water, you may use the built-in
navigation simulator to practice using the GPS
126/128. To use the simulator, see page 51.

Marking a Position

To begin the tour, let’s take the position you have
acquired (either by just initializing the unit or by hav­ing turned the unit on) and mark it as a waypoint for
future reference.

Press the UP arrow to
move forward through the
alphabet or numbers and
the DOWN arrow to
move backward.

8

1. Press the Mkey to capture and hold your position.

To mark a position, you must have obtained a

!

#

2D or 3D fix, or have the receiver in simulator
mode. If you try to mark a position without a
position fix, you will be alerted with a ‘No GPS
Position’ message.

The mark position page will appear, showing the
captured position and a default 3-digit waypoint name.
Let’s change the default name to something a little more
meaningful, like ‘DOCK’.

2. Press the down arrow once to move the field highlight
from the ‘SAVE?’ field to the name field.

3. Press Fto clear the default waypoint name.

GETTING

STARTED

4. Press and hold the
alphabet until the letter ‘D’ appears.

5. Press the
to the next character space.

6. Repeat steps 3 and 4 until the word ‘DOCK’ is dis­played.

7. Press

F

U

key to scroll through the

R

key once to move the character highlight

to complete entry of the name.

Each waypoint may also be assigned a custom way­point symbol for easy waypoint recognition on the map
page.

1. Press Fto activate the symbol menu.

2. Select the anchor symbol and press

3. Press the

4. Press

5. With the ‘SAVE?’ field highlighted, press
firm that you want to save the position as a waypoint
named ‘DOCK’.

key to highlight the ‘DONE?” field.

D

to confirm the selected symbol.

F

F

.

F

to con-

The mark position page will now be replaced by
the Position Page (or whatever page was displayed
prior to pressing the Mkey). The ‘DOCK’ waypoint
is now stored in the GPS 126/128’s memory, and will
remain there until you manually remove it or clear the
receiver’s memory. For more on waypoint management,
see pages 19-24.

Position and

Map Pages

The arrow keypad is used
for all data entry. Use the
UP and DOWN keys to
select letters, numbers, or
menu options, and use the
LEFT and RIGHT keys to
move the cursor forward or
backward along the line.

Using the Position and Map Pages

Now that you’ve marked a position, let’s see how
the Position and Map Pages can be used to monitor
your progress as you head out into the open water.

As always, ensure your primary focus is on

!

boating traffic and monitor the GPS126/128

#

briefly when operating your boat.

Position Page

9

GETTING

STARTED

Using the Position and Map Pages (cont.)

Position and

Map Pages

The Map Page displays
your present position as a
diamond icon and provides
a real-time graphic “bread­crumb” display of your
track right on the screen.

As you head out, the Position Page will help you

monitor your movement.

Graphic

Track Over

Ground

User-

Selectable

Field

Position
Display

Compass Tape

Current Speed

User-

Selectable

Field

12/24 Hour

Time

The direction you are moving (your track) and your
speed are displayed on the upper part of the page, just
below the graphic compass tape. The latitude and longi­tude, along with two user-selectable displays, are con­tinuously displayed in the middle of the page, and the
time of day is displayed below.

Now let’s change the display to the Map Page and
watch the track log of our tour:

1. Press the Jkey to change from the Position Page
to the Map Page.

To view a larger area on the Map Page, let’s change

the zoom scale from .2 (default) to 1.0 nautical mile.

To select a larger zoom scale on the

Map Page:

The moving map’s default
screen orientation is track­up. “Track up” means that
your current direction of
travel is always up (or
towards the top of) the
screen. It can also be set for
north up, or desired track­up orientation through the
map setup page.

10

1. Press the Hkey until ‘1.0 n.m. zoom scale’ appears.

Your current position is shown as the diamond in
the middle of the screen. The dark circle below the dia­mond represents the position you created, with the line
between the two showing your track.

1. Once you have reached an area that allows for gener­al changes in direction without interfering in the pas­sage of other boats, mark your current position again
and name this waypoint “CHANNL”. (See ‘Marking a
Position’ on page 18.)

2. Next, make a moderate turn in any direction thats safe
for navigation and proceed for another 3 minutes.

Going To a Waypoint

Once you’ve stored the “CHANNL” waypoint in
memory, you can use the GPS 126/128 to guide you to
it by performing a simple GOTO. A GOTO is nothing
more than a straight-line course from your present posi­tion to the destination you’ve selected.

Use caution when navigating. A “straight-line”

!

#

course reflects the shortest distance to a waypoint,
and does not navigate around obstructions, such
as land or buoys, etc.

Now that you have moved away from ‘CHANNL’ for
three minutes, let’s try navigating back to it.

GETTING

STARTED

Going To a

Waypoint

To select a GOTO destination:

1. Press the Gkey.

2. The GOTO waypoint page will appear, displaying all the
waypoints in memory in alphabetical order.

3. Use

U

or Dto highlight the ‘CHANNL’ waypoint.

4. Press the
gate to the displayed waypoint.

5. Press the

Bearing to

Waypoint

Track Over

Ground

Destination

Waypoint

“Finish Line”

Directional

Pointer

key to confirm that you want to navi-

F

key to view the Graphic Highway Page.

J

Destination Waypoint

User-

Selectable

Fields

Distance to

Waypoint

Speed Over

Ground

CDI Scale

Your Relative

Position

The GOTO waypoint page
allows you to select your
destination from a list of all
available waypoints in the
GPS 126/128’s memory.

Once a GOTO is activated,
the GPS 126/128 will
provid steering guidance
until the GOTO is can­celled. To cancel a GOTO,
highlight the cancel prompt
at the bottom of the page
and press ENTER.

11

REFERENCE

GOTO Waypoint

& Cancelling

GOTO

The 126/128 will also pro­vide steering guidance with
a graphic Compass Page.

To change the display from
the Highway Page, press
ENTER twice.

Going To a Waypoint (continued)

The GPS 126/128’s Highway Page provides graphic
steering guidance to a destination, with an emphasis on
a straight-line course to the desired waypoint and the
distance and direction you are off course. The bearing
and distance to a waypoint–along with your current
track and speed, are displayed at the top of the screen,
with two user-selectable fields shown at the bottom.

As you head toward your destination, the middle
section of the screen provides visual guidance to your
waypoint on a moving graphic “highway”. The pointer
just below the CDI scale always points to your selected
waypoint relative to the direction you are moving.

Your present position is represented by the diamond
in the center of the course deviation scale. The line
down the middle of the highway represents your
desired track. As you navigate toward a waypoint, the
highway will actually move, indicating the direction
you’re off course, relative to the position diamond on
the CDI scale. To stay on course, simply steer toward
the center of the highway.

While navigating, you may decide to use the
Compass Page (see picture above left) instead of the
Highway Page.

To select the Compass Page:

Once you reach the selected
distance from the destina­tion (based on your present
speed and course), an
arrival message will appear
on the message page.

12

1. While viewing the Highway Page, press Ftwice.

The Compass Page will now become the displayed
navigation page. This page provides a directional point­er to your destination by using a rotating compass dis­play to show direction of travel. It provides better steer­ing guidance at slower speeds for travel with many
directional changes.

To switch back to the Highway Page, press ENTER
twice.

Cancelling a GOTO

If you decide to stop navigating to the active way­point, all you have to do is cancel the GOTO.

To cancel an active GOTO:

1. Press the Gkey.

2. Use the arrow keypad to move the field highlight to
the ‘CANCEL GOTO?’ prompt at the bottom of the page
and press

F

.

Clearing a Cluttered Map Display

After you’ve used the GPS 126/128 for a few trips,
you may find that your map display has become a bit
messy from keeping track of your every move. For
practice, let’s clean up the screen by clearing the track
log (the plot points left on the Map Page) we’ve just
created during the Getting Started Tour.

REFERENCE

Clearing the

Map, Adjusting

Contrast, &

Power Off

1. Press Jor Quntil the Map Page appears and
press

2. Use the
‘TRACK SETUP’ option.

3. Press

4. Highlight the ‘CLEAR LOG?’ option. The clear log con­firmation page will appear.

5. Use the

6. Press

.

F

D

key to move the field highlight to the

to access the track setup page.

F

L

key to highlight the ‘Yes’ prompt.

to finish.

F

Adjusting the Contrast

You can adjust the screen contrast from the Satellite

Page and also from the Menu Page (see page 47)

To adjust the contrast from the Satellite Page:

1. Press the Jor Qkey until the Satellite Page
appears.

2. Press the arrow keypad left or right until the desired
level is reached, and press

F

.

Turning the Receiver Off

You’ve now gone through the basic operation of
your new GPS receiver. We encourage you to experi­ment with the GPS 126/128. If you encounter any
problems using the unit or want to take advantage of
the GPS 126/128’s more advanced features, refer to the
reference section of this manual.

To turn the GPS 126/128 off:

1. Press and hold the Pkey for 3 seconds.

Highlight the ‘CLEAR
LOG?’ prompt and press
ENTER to clear the track
log. Once all 1024 points
are used, the oldest point
will be continuously deleted
to make room for the latest
track log point.

Instantly change the screen
contrast by pressing the
arrow keypad while viewing
the Satellite Page.

13

REFERENCE

Satellite Page

Satellite Page

The GPS 126/128’s
Satellite Page will help
you determine which
satellites are in view, and
whether or not any satel­lites are being “shaded”
or blocked. (See satellites
07 and 19 above).

By periodically monitor­ing the signal strength
bars at the bottom of the
page and the north up
sky view, you will be able
to see how moving to
another area with a
clearer view of the sky
will improve satellite
reception and speed up
signal acquisition.

14

Status

Field

Horizontal
Accuracy

Skyview
Display

Signal Strength

Indicators

The GPS 126/128’s Satellite Page displays the status
of various receiver functions. The status information
will help you understand what the GPS 126/128 is
doing at any given time, and will tell you whether or
not the receiver has calculated a position fix.

Sky View and Signal Strength Bars

The sky view and signal strength bars give you an
indication of what satellites are visible to the receiver,
whether or not they are being used to calculate a posi­tion fix, and the signal quality. The satellite sky view
shows a bird’s-eye view of the position of each available
satellite relative to the unit’s last known position. The
outer circle represents the horizon (north or track up);
the inner circle 45º above the horizon; and the center
point directly overhead. You can use the sky view to
help determine if any satellites are being blocked, and
whether you have a current position fix (indicated by a
‘2D NAV’ or ‘3D NAV’ in the status field). You can also
set the sky view to a track-up configuration by changing
the “orientation” option on the Map Page. (See pg. 41
for Map Setup instructions.)

When the receiver is looking for a particular satel­lite, the corresponding signal strength bar will be blank
and the sky view indicator will be highlighted. Once the
receiver has found the satellite, a hollow signal strength
bar will appear, indicating that the satellite has been
found and the receiver is collecting data from it. The
satellite number in the sky view will no longer appear
highlighted. As soon as the GPS 126/128 has collected
the necessary data to calculate a fix, the status field will
indicate a 2D or 3D status.

Receiver Status and EPE

Receiver status is indicated at the top left of the
page, with the current horizontal accuracy (EPE, esti­mated position error, in feet or meters) at the top right.
The status will be shown as one of the following condi­tions:

Searching—

available satellites in view.

AutoLocate—

collecting new almanac data. This process can take

5 minutes, depending on the satellites currently in

view.

Acquiring—

available satellites, but has not collected enough

data to calculate a 2D fix.

2D Navigation—

good geometry have been locked onto and a 2-

dimensional position fix (latitude and longitude) is

being calculated. ‘2D Diff’ will appear when you are

receiving DGPS corrections in 2D mode.

3D Navigation—

geometry have been locked onto, and your position

is now being calculated in latitude, longitude and

altitude. ‘3D Diff’ will appear when you are receiving

DGPS corrections in 3D mode.

Poor GPS Coverage—

enough satellites for a 2D or 3D fix.

Not Usable—

due to abnormal satellite conditions. Turn the unit

off and back on to reset, and reinitialize the receiv-

er if necessary.

Simulator—

the GPS 126/128 is looking for any

the GPS 126/128 is initializing and

the receiver is collecting data from

at least three satellites with

at least four satellites with good

the receiver isn’t tracking

the receiver is unusable, possibly

the receiver is in simulator mode.

Screen Backlighting

The GPS 126/128 feature illuminates the screen
display for a user-defined interval (the default is 15 sec­onds). There are three stages of backlighting. When
backlighting is on, a bulb icon will appear at the bot­tom left of the sky view. To adjust the duration of
screen backlighting, refer to the system setup section
(see page 47).

Note: A bulb icon will appear on the Satellite Page

when backlighting is on.

REFERENCE

Receiver Status

& Screen

Backlighting

The signal strength bars at
the bottom of the page will
not appear until the GPS
126/128 has found the
satellites indicated at the
bottom of the screen.

When backlighting is on, a
bulb icon will appear on
the Satellite Page.

Use the icon to determine
if backlighting is turned
on during daylight hours.

15

REFERENCE

EZinit Prompt

and Memory

Erase

If you travel more than
500 miles with the receiv­er off, reinitialize the unit
to your new position by
using the EZinit feature.
To access EZinit, press
ENTER from the Satellite
Page before any satellites
are acquired.

Upon activating the
Memory Erase Function,
you will be asked to con­firm your decision.

EZinit Option Prompt

The Satellite Page also provides access to the EZ

init

prompt whenever a position fix has not been calculated.
(The unit must be in searching, AutoLocate, acquiring,
simulator, or poor coverage mode.) This allows you to
reinitialize the unit (see Appendix A), and is useful if
you have traveled over 500 miles with the receiver off
and must initialize your new position. (The EZ

init

prompt will automatically appear if the receiver needs
to be initialized. The prompt may also appear during
normal use if the antenna is blocked from receiving
satellite signals.

Note: The GPS 126/128 features an internal lithium
battery that will maintain the unit’s memory when the
receiver is not running.

Memory Erase Function

You may erase the GPS 126/128’s memory in four
quick steps. This will cause all stored data to be deleted,
including routes, waypoints, and the track log.

To erase all stored data:

1. Ensure that the GPS 126/128 is turned off.

2. While holding down the Mkey, press the Pkey
to turn the unit on. After the unit turns on, release the
keys. A warning message will appear with “Yes?”
highlighted, and ask you to confirm your selection.

3. If you do not wish to erase all stored data, press

and Fto cancel the emergency erase.

4. If you do wish to complete the emergency erase, press

to confirm.

F

R

Position Page

The second page in the GPS 126/128’s main page
sequence is the Position Page. This page shows you
where you are, what direction you’re heading, and how
fast you’re going. The Position Page is most useful when
you are traveling without an active destination way­point. The graphic compass tape across the top of the
page indicates the direction you’re heading (only while
you’re moving).

16

Position Page (continued)

Directly below the graphic compass tape are the
track and speed fields. Track is the compass direction
representing your actual course over the ground, and
Speed is how fast you’re moving. Below track and
speed are two user-selectable fields. Both user selec­table fields can display a variety of information that will
aid in navigation The left field offers options for TRIP
(default), AVSPD, MXSPD, TTIME, and ELPSD. The
right field offers options for ALT (default), TTIME,
ELPSD, and TRIP.

The following user-selectable options are available
on the Position Page:

Trip Odometer (TRIP)—

total distance

traveled since last reset.

Trip Timer (TTIME)—

total (cumulative)
time in which a ground speed has been
maintained since last reset.

Elapsed Time (ELPSD)—

hours and

minutes since last reset.

Average Speed (AVSPD)—

average speed

traveled.

Maximum Speed (MXSPD)—

maximum

speed traveled since last reset.

Altitude (ALT)—

vertical distance above

sea level.

To change the user-selectable fields

1. Highlight the left or right user-selectable field and
press

2. Use the
able options.

3. Press

.

F

U orD

F

key to scroll through the avail-

to confirm your selection.

The trip odometer, trip timer, and average speed
fields are linked. Resetting one of these options in a
user-selectable field will automatically reset the corre­sponding data in the other. This ensures that informa­tion shown in these fields reflects your current trip.

REFERENCE

Position Page

The speed and track dis­played on the position
page may fluctuate at
slow speeds (or when
you’re not moving)
because of position errors
caused by Selective
Availability.

The user-selectable fields
on the Position Page give
you a variety of informa­tion to choose from.

17

REFERENCE

Altitude Field &

Marking a

Position

Resetting the trip odome­ter will erase the previous
mileage and set the
odometer to 0.

You may enter a known
altitude to assist the GPS
126/128 in establishing a
3D fix.

Altitude Field

When the GPS 126/128 is acquiring satellites or
navigating in the 2D mode, the last known altitude is
used to compute your position. In cases where the GPS
126/128 has 2D coverage, entering your approximate
altitude will enable the receiver to determine a 3D fix.

Note: The altitude can not be changed when the
GPS 126/128 has a 3D position fix.

To enter an altitude:

1. Ensure that ‘ALT’ is displayed in the user-selectable
field.

2. Highlight the ‘ALT’ value field, and press

3. Enter a value, and press

F

.

F

.

Directly below the user-selectable fields is the
Position field. The position field shows the current GPS
position in latitude and longitude (default) or a user
selectable position format (see navigation setup page

47). Directly below the position field is the time. Time
can be displayed as a 12– or– 24 hour clock (see system
setup page 46).

Marking A Position

The GPS 126/128 allows you to mark and store up
to 500 positions as waypoints. A waypoint can be
entered by taking an instant electronic fix, by manually
entering coordinates (pg. 21), or using the bearing and
distance to a known position (pg. 22).

To mark your present position:

1. Press M. The mark position page will appear,
showing the captured position and a default three­digit name.

2. To save a default name and symbol, press
confirm the ‘Save?’ prompt.

To enter a different waypoint name:

1. Highlight the waypoint name field, and press F.

2. Make the appropriate changes, and press

3. Highlight ‘SAVE?’, and press

F

.

F

F

to

.

Note: To enter a different waypoint symbol or com-

ment, see pg. 23.

18

To add this waypoint to a route:

1. Highlight the ‘Add to route number’ field, and press
.

F

2. Enter a route number, press

press

again to save the waypoint.

F

to confirm and

F

Position Averaging Function

The GPS 126/128 positioning averaging function
will help reduce the effects of selective availability
when marking a waypoint.

Note: As the GPS 126/128 calculates the FOM, it
will rapidly change before it stabilizes on one number.

1. After you have pressed the Mkey, highlight the
‘AVERAGE?’ field and press
(FOM) field will display the value reflecting estimated
accuracy of the averaged position.

2. The unit will continue averaging until you have high-

lighted ‘SAVE?’ and pressed

. The Figure of Merit

F

.

F

Waypoint Pages

The GPS 126/128 has three waypoint pages that let
you quickly manage up to 500 waypoints. These
pages— nearest waypoints, waypoint list, and waypoint
definition— can be accessed through the Menu Page.

To select a waypoint page:

1. Access the Menu Page, and highlight a waypoint
page option.

2. Press

F

.

Nearest Waypoints Page

The nearest waypoints page shows the nine nearest
waypoints within 100 miles of your present position,
with the bearing and distance noted for each waypoint.
This page will let you retrieve a waypoint definition
page or GOTO a selected waypoint right from the list.

To review the waypoint definition page of a
selected waypoint:

1. Highlight the desired waypoint.

F

.

2. Press

REFERENCE

Position

Averaging &

Waypoint Pages

The GPS 126/128 will
save new waypoints with
a default three-digit
name. To add the way­point to a route, enter the
desired route number,
highlight ‘SAVE?’, and
press ENTER.

After initiating the posi­tion averaging function, a
Figure of Merit value will
be displayed, and the
‘SAVE?’ field will auto­matically be highlighted.

19