Time Station Emulator Turns Phones into Atomic Clock Synchronizers

For owners of radio-controlled clocks and watches—those self-setting timepieces marketed as 'atomic clocks'—reliable synchronization has always been geographically constrained. These devices depend on low-frequency radio signals from just five terrestrial stations worldwide (BPC in China, DCF77 in Germany, JJY in Japan, MSF in the UK, and WWVB in the US). Urban interference, building materials, and distance from transmitters often render this feature unusable. The Time Station Emulator project eliminates this limitation by transforming nearly any modern smartphone or tablet into a personal time signal broadcaster.

Developed by kangtastic and hosted at timestation.pages.dev, this browser-based tool generates authentic low-frequency signals (between 40-80 kHz) through a device's speaker. When placed near a radio-controlled clock, the audio emissions mimic official time stations with precision. The system pulls current time data using an NTP-like network synchronization algorithm, then encodes it into the specific modulation patterns required by each regional standard.

Key technical capabilities include:

• Full compatibility with all five major time signal protocols
• Automatic daylight saving time adjustments (for DCF77, MSF, WWVB)
• Leap second compensation via DUT1 offset transmission
• Time-shifting functionality (±24 hours) for testing or timezone simulation
• Entirely client-side operation—no installations, accounts, or data collection

The implementation relies on WebAssembly for signal processing efficiency and requires a browser supporting ≥44.1 KHz PCM audio output via the Web Audio API. While most modern devices meet these requirements, notable exceptions include Safari on iOS and Firefox on Android due to browser-specific audio limitations. Performance is optimal using built-in speakers rather than Bluetooth accessories.

What makes this approach innovative is its circumvention of hardware limitations. Traditional radio clock synchronization demands specialized low-frequency transmitters, yet kangtastic's solution repurposes ubiquitous consumer devices through software-defined radio techniques. By generating amplitude-modulated signals at carrier frequencies corresponding to official stations, it effectively 'tricks' clocks into synchronization without hardware modifications.

Potential use cases extend beyond convenience: museums maintaining vintage radio clocks, field researchers in remote locations, or engineers validating device behavior could leverage this tool. Its open-source MIT license (view repository) also invites further development, such as expanded protocol support or signal optimization research.

The project exemplifies how browser technologies can solve physical-world constraints. While not a replacement for official time signals in critical applications, it democratizes access to precision timekeeping where infrastructure falls short—turning signal dead zones into synchronized spaces with devices already in our pockets.