Welcome to Contest Audio Live

Have you ever wanted to...

listen in on a serious SO2R DX contest effort? 

hear what the low bands sound like from New England?

enjoy a contest without having access to a radio?

This is your chance!

Live Audio (available only during select contests)

During some of the serious contest operations from K5ZD, we will enable live audio streaming direct from the headphones.  Click on the link below any time during the contest to listen in on what conditions the operator is experiencing.

Listen to live audio now (http://d.liveatc.net/k5zd.m3u)

Notes:

To listen, you will need software capable of receiving streaming MP3 broadcasts (e.g., Winamp, Media Player, Real Player, iTunes, etc.)

If you get disconnected, click on the link again to restart.

Choose one of the following recordings of past contests:

WW CW 2010 (K5ZD op) Log Search and Audio New!

WRTC 2010 R34P (K5ZD, W2SC ops) Log Search and Audio

WRTC 2010 R34P Full Audio files

WW CW 2008 (K5ZD op)

WW Phone 2008 (K5ZD op)

North American Sprint CW, Feb 2008 (K5ZD op)

WW CW 2007 (K5ZD op)

WW Phone 2007 (K5ZD op)

WW CW 2006 (K5ZD op)

WW Phone 2005 (KM3T op)

WW CW 2005 (K5ZD op)

ARRL DX CW 2006 (N5KO, K5ZD ops)

These contest recordings provide a great way to listen and learn, warm up your ears for the next contest, and listen to what your signal sounded like at K5ZD!

How it Works

This experiment in real-time contest audio is made possible through the resources of www.liveatc.net, a site for aviation enthusiasts that provides streaming of live Air Traffic Control (ATC) radio traffic from around the world.

There have been a lot of questions about how the streaming is being done. 

The system uses MP3 streaming via a network of Icecast2 (www.icecast.org) servers (running on Linux, & FreeBSD, but Icecast2 runs fine on Windows, too).

The whole system is based on replicated unicast:

The broadcasting machine uses a version of Stream Transcoder (http://www.oddsock.org/tools/streamTranscoder/) to feed a central server running Icecast2 (from www.icecast.org).

Listeners connect to the central Icecast2 server, which runs a custom instance of Icecast running on a special port for load balancing. The listener is then redirected to one of the replicated (slave) servers. The slave server then "pulls" the requested stream from the central Icecast2 server (i.e., only the requested streams are replicated). It's proven to be a very reliable system.

It all boils down to having access to bandwidth. CPU/RAM requirements are minimal since Icecast has a pretty small memory footprint and CPU loading. All the encoding is done on the broadcaster end - Icecast is just "passing the stream."

The system is currently limited to about 1,000 listeners, mainly to conserve bandwidth, but it is scalable to thousands of simultaneous users. Best of all it's standards-based so any client software capable of receiving MP3 audio streams can tune in.

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Copyright 2000-2011 by Randy Thompson, K5ZD
E-mail to k5zd@k5zd.com