Introduction
This manual provides instructions for the setup, operation, and maintenance of your MARATHON CL030025 Jumbo Atomic Wall Clock. This digital clock features self-setting atomic time, a large display for easy readability, and includes temperature and date functions. It is designed for indoor use and can be wall-mounted or used with its integrated stand.

Image: The CL030025 Jumbo Atomic Wall Clock held by a person, highlighting its large display and sleek design.
Package Contents
- MARATHON CL030025 Jumbo Atomic Wall Clock
- AA Batteries (Quantity: 1)
- Instruction Manual (this document)

Image: The CL030025 clock shown in its premium retail packaging.
Setup
1. Battery Installation
- Locate the battery compartment on the back of the clock.
- Open the battery compartment cover.
- Insert one AA battery, ensuring the correct polarity (+ and -).
- Close the battery compartment cover.
2. Initial Atomic Signal Reception
Upon battery installation, the clock will automatically begin searching for the WWVB atomic time signal from Fort Collins, Colorado. This process may take several minutes to several hours, depending on your location and environmental conditions. A signal strength indicator (often a tower icon with waves) will appear on the display once a signal is received.
- For best reception, place the clock near a window and away from electronic devices that may cause interference.
- Avoid placing the clock on or near metal surfaces.
3. Time Zone and DST Setting
The clock typically defaults to Pacific Standard Time (PST). You may need to manually set your time zone and Daylight Saving Time (DST) preference. Refer to the buttons on the back of the clock for specific controls (e.g., "TIME ZONE", "DST").
4. Mounting the Clock
The clock can be wall-mounted or placed on a flat surface using its integrated stand.
- Wall Mounting: Use a screw (not included) and the keyhole slot on the back of the clock to securely hang it on a wall.
- Tabletop Use: Extend the integrated stand on the back of the clock to place it on a desk or shelf.

Image: The CL030025 clock displayed on an office wall, showing its suitability for various environments.
Operating Instructions
1. Reading the Display
The large digital display shows the current time (with AM/PM indicator), seconds, month, date, day of the week, and indoor temperature.

Image: A user interacting with a tablet, with the CL030025 clock clearly visible on the wall in the background, demonstrating its readability.
2. Temperature Unit Selection
To switch between Celsius (°C) and Fahrenheit (°F) temperature display, locate the "°C/°F" button on the back of the clock and press it.
3. Manual Time Setting (If Atomic Signal Unavailable)
In areas where the atomic signal cannot be received, you can manually set the time. Refer to the buttons on the back of the clock, typically labeled "SET", "HOUR", "MINUTE", etc., to adjust the time manually.
Maintenance
1. Battery Replacement
When the battery low indicator appears on the display, replace the AA battery promptly to ensure continuous operation and accurate timekeeping. Follow the battery installation steps outlined in the Setup section.
2. Cleaning
Wipe the clock's display and frame with a soft, dry cloth. Do not use abrasive cleaners or solvents, as these may damage the surface.
Troubleshooting
- Clock not displaying time: Ensure batteries are correctly installed and not depleted. Replace if necessary.
- No atomic signal reception:
- Relocate the clock to a different position, preferably near a window and away from electronic interference.
- Allow up to 24 hours for the clock to receive the signal, especially during initial setup or after battery replacement.
- Manually set the time if consistent signal reception is not possible in your location.
- Incorrect time displayed:
- Verify that the correct time zone is selected.
- Check DST settings if applicable to your region.
- Ensure the atomic signal is being received (check signal indicator).
Specifications
| Model Number | CL030025 |
| Brand | MARATHON |
| Display Type | Digital |
| Power Source | Battery Powered (1 x AA) |
| Operation Mode | Atomic (Self-Setting) |
| Indoor/Outdoor Usage | Indoor |
| Mounting Type | Wall Mount / Tabletop Stand |
| Item Weight | 1152 Grams |
| Dimensions | Approximately 16.65 inches (42.3 cm) x 10.62 inches (26.97 cm) |
| UPC | 063442321058 |

Image: Dimensional drawing of the CL030025 clock, indicating its width and height.
Product Video
Video: An official product video demonstrating the features and functionality of the MARATHON CL030025 Jumbo Atomic Wall Clock, including its self-setting capabilities and display of time, date, and temperature.
Warranty and Support
MARATHON products are manufactured to high-quality standards. For information regarding warranty coverage, technical support, or service, please refer to the contact details provided on the product packaging or visit the official MARATHON website. Keep your purchase receipt as proof of purchase for warranty claims.