Cobra ACXT390 Two-Way Radio Instruction Manual

1. Introduction

The Cobra ACXT390 Walkie Talkies are compact and lightweight two-way radios designed for reliable communication. They feature 22 channels and 121 privacy codes, offering a total of 2662 channel combinations to minimize interference. Equipped with a built-in NOAA radio receiver, these radios provide 24/7 access to weather alerts, ensuring preparedness for changing conditions. Voice-activated (VOX) transmission allows for hands-free operation, and five selectable call tones help distinguish between different parties.

This manual provides essential information for the proper setup, operation, and maintenance of your Cobra ACXT390 two-way radios.

2. Setup

2.1 Package Contents

Before beginning, verify that all items are present in your package:

• 2x Cobra ACXT390 Walkie Talkies
• 2x Belt Clips
• 6x AA NiMH Rechargeable Batteries
• 1x Charging Dock
• 1x USB-Y Cable

Figure 1: Cobra ACXT390 Package Contents

2.2 Battery Installation

Your Cobra ACXT390 radios use 3 AA NiMH rechargeable batteries per unit. To install or replace batteries:

1. Ensure the radio is powered off.
2. Locate the battery compartment cover on the back of the radio.
3. Press down on the release tab (if present) and slide the cover off.
4. Insert 3 AA NiMH batteries, observing the correct polarity (+/-) as indicated inside the compartment.
5. Replace the battery compartment cover, ensuring it clicks securely into place.

2.3 Charging the Radios

The included charging dock and USB-Y cable allow you to recharge the NiMH batteries while they are inside the radios.

1. Connect the USB-Y cable to the charging dock and a compatible USB power source (e.g., wall adapter, computer USB port).
2. Place the radios into the charging slots on the dock. Ensure the charging contacts on the radio align with those on the dock.
3. A charging indicator light on the radio or dock will illuminate, indicating that charging has begun.
4. Allow sufficient time for a full charge (refer to the full user manual for specific charging times).

3. Operation

3.1 Power On/Off

To power on the radio, press and hold the Power button until the display illuminates. To power off, press and hold the Power button again until the display turns off.

3.2 Channel Selection

Your ACXT390 radios offer 22 channels. To change channels:

1. Press the Mode button until the channel number flashes on the display.
2. Use the Up or Down arrow buttons to select your desired channel.
3. Press the Mode button again or wait a few seconds for the selection to be confirmed.

3.3 Privacy Codes (CTCSS/DCS)

The radios support 121 privacy codes (38 CTCSS / 83 DCS) to help reduce interference from other users on the same channel.

1. After selecting a channel, press the Mode button until the privacy code number flashes.
2. Use the Up or Down arrow buttons to select your desired privacy code.
3. Press the Mode button again or wait for the selection to be confirmed.

3.4 Volume Adjustment

Use the Volume Up and Volume Down buttons (often integrated with the channel buttons) to adjust the listening volume.

3.5 Transmitting and Receiving

To transmit, press and hold the Talk button (usually on the side of the radio) and speak clearly into the microphone. Release the Talk button to receive.

3.6 VOX (Voice-Activated Transmission)

VOX allows for hands-free communication. When activated, the radio will automatically transmit when it detects your voice.

Figure 2: VOX, Call Tones, and Channel Scan Features

3.7 Call Tones

The ACXT390 features 5 selectable call tones. To send a call tone, briefly press the Call button. This alerts other radios on the same channel to an incoming transmission.

3.8 Channel Scan

The channel scan feature allows you to automatically scan all 22 channels for activity. To activate, press the Scan button. The radio will stop on any active channel. Press Scan again to resume scanning.

3.9 NOAA Weather Channels

Access 24/7 NOAA weather channels to stay informed about local weather conditions and emergencies. To access, press the dedicated Weather button (if available) or cycle through modes until the weather channel is displayed.

Figure 3: Weather-Resistant Design and NOAA Weather Channels

3.10 Understanding Range

The advertised range of up to 25 miles is achieved under ideal conditions, such as flat, open terrain with a clear line of sight and no obstructions. In real-world scenarios, the effective range can be significantly shorter due to various factors:

• Urban Environments: Buildings and other structures can reduce the range to approximately 0.5 to 1.5 miles.
• Forested or Hilly Areas: Dense foliage and uneven terrain can further limit the range, often to less than a mile.
• Weather Conditions: Atmospheric conditions can impact signal propagation.

Figure 4: Walkie Talkie Range Explained

4. Maintenance

4.1 General Care

• Clean the radio with a soft, damp cloth. Do not use abrasive cleaners or solvents.
• Avoid exposing the radio to extreme temperatures, humidity, or direct sunlight for extended periods.
• The radios are weather-resistant (IPX2), meaning they can withstand light splashes, but are not designed for submersion.

4.2 Battery Care

• Always use the included rechargeable NiMH batteries and charging dock for optimal performance and safety.
• If storing the radios for an extended period, remove the batteries to prevent leakage.
• Dispose of old batteries responsibly according to local regulations.

5. Troubleshooting

5.1 No Power

• Check if the batteries are correctly installed and fully charged.
• Ensure the power button is pressed and held until the display turns on.

5.2 Poor Range or Static

• Verify that both radios are on the same channel and privacy code.
• Move to an open area with fewer obstructions (buildings, dense foliage, hills).
• Ensure batteries are fully charged, as low power can affect range.
• Consider the environmental factors affecting usable range as explained in Section 3.10.

5.3 Cannot Transmit or Receive

• Confirm that the Talk button is being pressed during transmission.
• Check if the radio is in VOX mode; if so, ensure you are speaking loud enough to activate transmission.
• Verify that the volume is set to an audible level.

6. Specifications

7. Warranty & Support

Cobra products are USA engineered and supported, reflecting over 50 years of proven reliability. For detailed warranty information, product registration, or technical support, please visit the official Cobra Electronics website or contact their customer service department.

Keep your proof of purchase for warranty claims.