WMFN (640 AM) is a Class B regional radio station licensed to PEOTONE, IL. Operating with 4 kW daytime power using a directional (different day/night patterns) antenna system with 4 towers. At night it operates at 2 kW. After sunset, skywave propagation can extend the signal across much of the surrounding region. The station is owned by Birach Broadcasting Corporation. It broadcasts a All-news radio format.