AM Coverage           

• The number of AM stations increased by 74 percent during this period, from 34 stations in 1989 to 59 stations today.  The number of AM stations comprises, however, a small percentage of the total number of public stations nationwide.
  
  
• Half the states have no AM stations.  Half the AM stations are clustered in four geographic regions of the country: Alaska, Oregon-Northern California, Midwest (Minnesota, Wisconsin, Iowa, Michigan, Indiana, Illinois and Ohio) and New York-Southern New England.  The remaining AM stations are scattered around the country with only one state, Colorado, having as many as three stations.
  
  
• Approximately 20 percent of the public AM stations are in Alaska.  Eleven of the 12 AM stations in Alaska broadcast with the same power and antenna pattern throughout the day.
  
  
• With the exception of Alaska, most AM stations serve areas that also receive public FM service.
  
  
• AM provides the only public radio service to approximately 45,000 people in Alaska.  This amounts to 7 percent of Alaska’s population and they have been added to the FM coverage population figures in the Alaska table and narrative.
  
  
• In order to protect the service areas of distant AM stations, the FCC requires that many AM stations change their broadcast coverage patterns at night.  Of the 47 public AM radio stations outside of Alaska, 12 must discontinue broadcasting at night.  An additional 18 of the non-Alaska public AM stations must reduce broadcast power or change their antenna pattern at night.  Therefore, almost two-thirds of the public AM stations outside of Alaska must reduce their coverage patterns at night.
  
  
• As in the 1989 study, the population covered by AM stations is not included on the state or national population totals reported in this study, other than in the Alaska state table and narrative. This is due to two factors.  The first reason is that most public AM stations outside of Alaska provide a limited broadcast schedule with coverage patterns that may change or even be discontinued after sundown.  People living in regions which lose nighttime service cannot be considered as receiving full public radio service.  Secondly, most public AM stations outside of Alaska serve areas that also receive public FM stations.  When considered nationally, the number of people who only receive public radio from AM stations, even during the daytime, is minimal and would not significantly impact the national coverage numbers.