Garmin GPS 48 Personal Navigator Manual

The Garmin GPS 48 is a rugged, waterproof personal navigator designed for outdoor use. It features a 12-parallel-channel GPS receiver, built-in quad-helix antenna, NMEA 0183 interface for marine applications, and stores up to 500 waypoints with graphic navigation screens. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: Waterproof case (IPX7), backlit LCD display, external antenna port, NMEA 0183 data port, power/data cable connector.

Installation

Unpack and inspect contents. Mount using optional bracket or carry in hand.

1. Install batteries: Open battery compartment, insert 4 AA batteries observing polarity.
2. External power: Connect red wire to positive (+), black wire to negative (-) of 10-40V DC source.
3. Mounting: Use optional mounting bracket with supplied hardware.
4. External antenna: Connect to MCX connector if needed for improved reception.

WARNING! Ensure proper polarity when connecting external power. Do not short circuit power wires.

First-Time Setup

Power on unit; follow initialization procedure.

1. Acquire satellites: Place unit outdoors with clear sky view, power on, wait for satellite acquisition.
2. Set preferences: Press MENU, navigate to Setup menu to configure units, time format, etc.
3. Initialize position: If prompted, enter approximate position for faster satellite acquisition.
4. Calibrate compass: Follow on-screen prompts if using magnetic compass features.

CAUTION! Initial satellite acquisition may take several minutes. Ensure clear view of sky.

Specifications

• GPS Channels: 12 parallel channels, WAAS enabled.
• Update Rate: 1 second continuous.
• Accuracy: Position: <15 meters RMS, Velocity: 0.1 knot RMS.
• Dynamics: Up to 999 knots, altitude limit 18,000 meters.
• Interfaces: NMEA 0183, RTCM 104 differential input.
• Power: 4 AA batteries (alkaline or NiMH), 10-40V DC external.
• Battery Life: Approximately 20 hours (alkaline, backlight off).
• Operating Temp: -15°C to 70°C (5°F to 158°F).
• Storage Temp: -40°C to 85°C (-40°F to 185°F).
• Waterproof: IPX7 standard.

Controls and Settings

Front Panel: POWER, PAGE, ENTER, QUIT, ROCKER key (up/down/left/right).

Key Functions: POWER: Turns unit on/off. PAGE: Cycles through display pages. ENTER: Selects options/marks waypoints. QUIT: Returns to previous screen. ROCKER: Navigates menus/moves cursor.

Setup Menu: Units (statute/nautical/metric), Time (12/24 hour), North Reference (True/Magnetic), Display contrast, Backlight timeout, System mode (normal/battery save). Navigation Menu: Waypoint management, Route creation, Track log controls, Goto navigation, MOB (Man Overboard) function.

Connecting Devices

NMEA 0183: Connect to chart plotters, autopilots, or other marine electronics. Power/Data cable: For external power and data transfer.

1. Turn off all devices before connecting cables.
2. Connect NMEA wires: TX+ to RX+ on receiving device, TX- to RX-.
3. Power connection: Red to positive, black to negative, shield to ground.
4. Secure connections with waterproof sealant in marine environments.

Tip: Use shielded cable for NMEA connections to reduce interference.

Navigation & Waypoints

Create and navigate to waypoints, build routes, track your path.

1. Mark waypoint: Press ENTER at current location, name waypoint, select symbol.
2. Goto navigation: Select waypoint from list, press GOTO, follow bearing/distance display.
3. Create route: Select New Route, add waypoints in sequence, activate for navigation.
4. Track log: Enable track recording, use Trackback to retrace path.
5. MOB function: Press and hold ENTER for 3 seconds to mark Man Overboard position.
6. Project waypoint: Create new waypoint at specified distance/bearing from existing.
7. Navigate route: Follow active route with turn-by-turn guidance.
8. Arrival alarm: Set proximity alarm for waypoint arrival.

WARNING! GPS accuracy affected by atmospheric conditions, obstructions. Always use with caution for critical navigation.

Advanced Features

DGPS capability: Connect to external differential beacon receiver for improved accuracy. Sun/Moon information: Display sunrise/sunset, moon phase data. Proximity waypoints: Set alarm radius around critical points. Simulator mode: Practice navigation without satellite signals.

Care & Maintenance

Clean with fresh water after saltwater use. Use mild soap and soft cloth. Ensure battery compartment seal is clean and intact.

CAUTION! Do not use harsh chemicals, solvents, or high-pressure sprays. Replace O-rings annually if used in saltwater.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits. This device complies with part 15 of the FCC Rules. Operation is subject to the condition that this device does not cause harmful interference. Copyright © Garmin Ltd. or its subsidiaries. For support, visit www.garmin.com or contact Garmin Product Support.

Troubleshooting

Reset: Press and hold PAGE + POWER during power-on for master reset (erases all user data).

Service: Contact Garmin Product Support or authorized service center.