Introduction
This manual provides comprehensive instructions for the setup, operation, and maintenance of your MARATHON Round Atomic Alarm Clock. This device automatically synchronizes with the NIST radio signal for accurate timekeeping and features a digital display for time, date, day, and indoor temperature.

Figure 1: MARATHON Round Atomic Alarm Clock, Graphite Gray.
Package Contents
- MARATHON Round Atomic Alarm Clock (Graphite Gray)
- 2 x AAA Batteries
- Instruction Manual (this document)
Product Overview
The MARATHON Round Atomic Alarm Clock is designed for ease of use and precise timekeeping. It features a clear digital display and intuitive controls.

Figure 2: Rear view of the clock with controls.
Key Features:
- Atomic Time Synchronization: Automatically sets and adjusts time via NIST radio signal (North America only).
- Digital Display: Shows time (12/24-hour), date, day of the week, and indoor temperature.
- Push-Button Backlight: Provides a 5-second illumination for viewing in low light.
- Alarm with Snooze: Features an 8-minute snooze function.
- Eight Time Zones: Selectable time zones for North America (Pacific, Mountain, Central, Eastern, Atlantic, Newfoundland, Alaska, Hawaii).
- Temperature Display: Switchable between Celsius (°C) and Fahrenheit (°F).
Setup
1. Battery Installation
- Locate the battery compartment on the back of the clock (refer to Figure 2).
- Open the battery compartment cover.
- Insert the two AAA batteries, ensuring correct polarity (+ and -).
- Close the battery compartment cover securely.
Upon battery installation, the clock will automatically begin searching for the atomic time signal.
2. Atomic Time Synchronization
- Place the clock near a window for optimal signal reception.
- The clock will attempt to synchronize with the NIST radio signal. This process may take several minutes to a few hours, depending on your location and environmental conditions.
- A signal strength indicator (often a tower icon) on the display will show the reception status. A solid icon indicates successful synchronization.
- If the clock does not synchronize after several hours, try relocating it to a different position or window.
3. Setting Time Zone
Once synchronized, the clock will display the default time zone. To adjust:
- Locate the "TIME ZONE" button on the back of the clock (refer to Figure 2).
- Press the "TIME ZONE" button repeatedly to cycle through the available North American time zones: Pacific (P), Mountain (M), Central (C), Eastern (E), Atlantic (A), Newfoundland (N), Alaska (L), and Hawaii (H).
- Stop pressing when your desired time zone is displayed. The clock will automatically adjust the time.
4. Setting 12/24-Hour Format and Temperature Unit
These settings are typically adjusted using dedicated buttons or a combination of buttons on the back of the clock.
- Time Format: Look for a button labeled "12/24H" or similar. Press it to toggle between 12-hour (with AM/PM indicator) and 24-hour formats.
- Temperature Unit: Look for a button labeled "°C/°F" or similar. Press it to switch the indoor temperature display between Celsius and Fahrenheit.
Operating Instructions
1. Using the Backlight
- The clock features a push-button backlight for temporary illumination.
- Press the large button located on the top of the clock (often labeled "SNOOZE/LIGHT").
- The display will illuminate for approximately 5 seconds.
2. Setting and Using the Alarm
To set the alarm time:
- Locate the "ALARM SET" button on the back of the clock. Press and hold it until the alarm time begins to flash.
- Use the "+" and "-" buttons (or similar adjustment buttons) to set the desired alarm hour.
- Press "ALARM SET" again to confirm the hour and move to setting the minutes.
- Use the "+" and "-" buttons to set the desired alarm minutes.
- Press "ALARM SET" one last time to confirm and exit alarm setting mode.
To activate/deactivate the alarm:
- Locate the "ALARM ON/OFF" switch or button, typically on the side or back of the clock (refer to Figure 2).
- Slide the switch to "ON" or press the button to activate the alarm. An alarm icon will appear on the display.
- Slide the switch to "OFF" or press the button again to deactivate the alarm. The alarm icon will disappear.
3. Snooze Function
- When the alarm sounds, press the large "SNOOZE/LIGHT" button on the top of the clock.
- The alarm will temporarily stop and sound again after approximately 8 minutes.
- To turn off the alarm completely, slide the "ALARM ON/OFF" switch to "OFF" or press any other button (consult specific model instructions if this varies).
Maintenance
Battery Replacement
- When the display dims or functions become erratic, it is time to replace the batteries.
- Open the battery compartment on the back of the clock.
- Remove the old AAA batteries and dispose of them properly according to local regulations.
- Insert two new AAA batteries, observing correct polarity.
- Close the battery compartment. The clock will restart the atomic synchronization process.
Cleaning
- Wipe the clock with a soft, dry cloth.
- Do not use abrasive cleaners, solvents, or chemical sprays, as these may damage the casing or display.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Clock not synchronizing with atomic time. | Weak signal, interference, incorrect location. |
|
| Incorrect time displayed after synchronization. | Incorrect time zone selected. | Press the "TIME ZONE" button to select the correct time zone for your region. |
| Display is dim or blank. | Low or depleted batteries. | Replace the AAA batteries with new ones. |
| Alarm does not sound. | Alarm is not activated or set incorrectly. |
|
Specifications
| Feature | Detail |
|---|---|
| Brand | MARATHON |
| Model Number | B09MV4KPVF |
| Color | Graphite Gray |
| Power Source | Battery Operated (2 x AAA batteries, included) |
| Display Type | Digital LCD |
| Special Features | Atomic Time, Alarm, Snooze, Backlight, Temperature Display (°C/°F), Date, Day, 8 Time Zones |
| Material | Plastic |
| Dimensions | Approximately 3.62 x 3.62 x 2.05 inches (9.2 x 9.2 x 5.2 cm) |
| Item Weight | 4 ounces (113 grams) |
| Connectivity Technology | Radio Frequency (NIST signal) |
| UPC | 063442322451 |

Figure 3: Product Dimensions.
Warranty and Support
MARATHON products are manufactured with quality and precision. For specific warranty information, please refer to the documentation included with your purchase or visit the official MARATHON website. For technical support or inquiries, please contact MARATHON customer service through their official channels.
You can find more information and support at the MARATHON Brand Store.

