WOI (640 AM) is a Class B regional radio station licensed to AMES, IA. Operating with 5 kW daytime power using a directional (different day/night patterns) antenna system with 2 towers. At night it operates at 1 kW. After sunset, skywave propagation can extend the signal across much of the surrounding region. The station is owned by Iowa Public Radio, Inc. It broadcasts a Public radio; talk radio format.