Decode WWV

We'll choose to listen to their 10MHz signal. This is often heard day or night in the North American continent. The WWV Frequency List offers other options.

We recover time codes and a variety of other signals by decoding the Double Side Band modulation. The resulting audio contains a variety of signals multiplexed by a variety of methods. See WWV Broadcast Schedule for many choices.

Underneath all the other signals a narrow-band digital signal continuously carries the time of day. We'll extract that signal and leave the rest behind.

Short and long pulses encode zeros and ones. Messages are 59 bits long. A missing bit (the hole) signals the start of a new data frame. Try adding a Scope here.

Each bit of the message is given a specific meaning defined by the WWV Timecode Format. This is assembled into a human readable string in the browser's local timezone.

The decoded bits are transmitted from the digital radio server to this web page through a Web Socket. Typical latency will be 10 to 100 milliseconds. This is a long time by WWV standards but wholly adequate for a one-second clock.