ICOM M424G 21 Fixed Mount VHF Radio with Internal GPS User Manual

1. Introduction

This manual provides essential information for the proper installation, operation, and maintenance of your ICOM M424G 21 Fixed Mount VHF Radio with Internal GPS. Please read this manual thoroughly before using the radio to ensure safe and efficient operation.

Front view of the ICOM M424G 21 VHF radio, showing the main unit with its display, control buttons, and rotary knobs, alongside the connected hand microphone.

2. Setup

2.1 Unpacking

Verify that all components are present:

• ICOM M424G 21 VHF Radio Unit
• Hand Microphone
• Mounting Bracket (may be sold separately)
• Power Cable
• User Manual (this document)

2.2 Mounting

The ICOM M424G 21 can be flush-mounted or installed using a bracket. Ensure the mounting location provides adequate ventilation and is protected from direct exposure to extreme weather conditions, although the unit offers IPX7 submersible protection.

• Flush Mounting: Requires careful cutting of the dashboard or panel. Refer to the provided template for precise dimensions.
• Bracket Mounting: Secure the supplied or compatible mounting bracket to a stable surface. Attach the radio unit to the bracket using the provided hardware. Note that some brackets may be sold separately.

2.3 Electrical Connections

Connect the radio to a 12-volt DC power source. Ensure proper polarity (red to positive, black to negative) and use appropriate fusing. Connect the VHF antenna to the antenna connector on the rear of the unit. The internal GPS receiver does not require an external GPS antenna.

3. Operating Instructions

3.1 Power On/Off and Basic Controls

• Power: Press and hold the VOL/SQL PWR knob to turn the unit on or off.
• Volume: Rotate the VOL/SQL PWR knob to adjust the speaker volume.
• Squelch: Press the VOL/SQL PWR knob momentarily, then rotate to adjust the squelch level to eliminate background noise.
• Channel Selection: Use the CH Up/Down buttons or the channel selector knob to change channels.
• Channel 16/Call Channel: Press the dedicated 16/C button for instant access to Channel 16 (distress and calling) or the user-programmed call channel.

3.2 Advanced Features

• Dual/Tri-Watch Function: Monitor Channel 16 and/or the call channel while operating on another channel. This feature is crucial for safety and communication.
• DSC (Digital Selective Calling): The M424G 21 supports DSC for distress calls, individual calls, group calls, and all ships calls. The internal GPS provides your position for distress signals.
• Weather Channels with Alert Function: Access NOAA weather channels and receive alerts for severe weather conditions.
• Aqua Quake Draining Function: This feature emits a vibrating sound to clear water from the speaker grille, maintaining clear audio even after exposure to water.
• MA-500TR AIS Transponder Compatibility: The radio is compatible with the MA-500TR AIS Transponder for enhanced vessel tracking and collision avoidance.
• Noise Canceling Microphone: The included microphone is designed to reduce background noise, ensuring clear voice transmission in noisy environments.

4. Maintenance

4.1 Cleaning

Regularly clean the radio unit and microphone with a soft, damp cloth. Do not use abrasive cleaners or solvents. Ensure the speaker grille is clear of debris, especially after exposure to water, and utilize the Aqua Quake function.

4.2 Water Protection

The ICOM M424G 21 offers IPX7 submersible protection, meaning it can withstand immersion in 1 meter of water for 30 minutes. While robust, avoid unnecessary exposure to water and ensure all caps and covers are securely fastened.

5. Troubleshooting

If you experience issues with your ICOM M424G 21, consider the following basic checks:

• No Power: Check power cable connections, fuse, and battery voltage.
• No Audio/Poor Audio: Adjust volume and squelch. Ensure the microphone is properly connected. Use the Aqua Quake function if water exposure is suspected.
• No Transmission/Poor Range: Check antenna connection and condition. Ensure power output is set correctly (1W or 25W).
• GPS Not Acquiring Position: Ensure the unit has a clear view of the sky. Allow sufficient time for initial acquisition.

For persistent issues, consult a qualified marine electronics technician or contact ICOM customer support.

6. Specifications

7. Warranty and Support

For warranty information, please refer to the documentation included with your product or visit the official ICOM website. For technical support, service, or replacement parts, please contact ICOM customer service directly.