LPFM Third Adjacent Channel Study (MITRE Report)

Third Adjacent Channel Availability Maps

These maps show the areas where LPFM is not available right now but would be available if the FCC rules were rolled back to the way they were originally approved prior to the Radio Broadcast Protection Act (RBPA). The areas in green are those that will receive new LP-100 service as a result of rolling back RBPA. The areas in gray will still not receive LPFM service. These maps use REC's ENAC (Every Nook And Cranny) program. This program runs a channel report at every point in the continental United States spaced every 2 minutes in latitude and longitude. These maps are based on the database as of August 22, 2003. This also includes translators filed for during the great translator invasion (which all future LPFMs will be required to protect) as well as the presence of any LPFM stations (including some that have been dismissed and not removed from the database). REC advises that this information should only be used for presentation purposes to show the possibile availability of future LP-100 service in areas if Congress repeals the RBPA. REC Networks does not warrant this data and we advise persons not to rely on this data to plan future LPFM stations. If portions of a state are not shown on the map, then those areas are considered places where LPFM is available today (noted on the map with a white background).

2016 historical note: These maps were developed in 2003 in response to the controversy over the (what would eventually be determined as unfounded) fear that LPFM stations would cause substantial interference to full-power stations on third-adjacent channels.  These maps show the areas where LPFM would not be available under the "current" (2003) post-RBPA statute protecting third adjacent (the grey areas of the maps) and what it could look like if third-adjacent channels are restored (the green areas of the map would still be blocked from LPFM).  


Third-adjacent channel access would eventually be restored in 2011 with the signing of the Local Community Radio Act of 2010 by President Obama.   Please note that these maps are retained for historical purposes and should not be considered any kind of modern indiciation of LPFM availability.  


It is also important to point out that these maps also did not anticipate the "second-adjacent channel waiver".  This was unheard of for LPFMs back in 2003.  Second adjacent channel waivers would come around later in the decade strictly as a method for addressing displacement by a full-service station move.  In those days, the waivers were given by special temporary authority and were allowed to have population in the overlap zone.  These arrangements would be invalidated with the passing of the LCRA in 2011 which codified second-adjacent channel waivers but only under the condition they cause no interference to "any radio service"

CONDITIONS OF USE - REC is providing these maps free of charge to the individuals and organizations who support the LPFM movement and the elimination of the third adjacent channel restrictions. Please feel free to use these maps in your filings as well as use them to communicate the impact of this change with your lawmakers. Please retain the REC logo or credit the maps to REC Networks. REC maintains copyright and title to this original creative work and we can revoke this license to anyone at any time.

State maps in JPEG format

Maps in Top-9 (2003) Aribitron markets

MITRE Third Adjacent Study

As a part of the passage of the Radio Broadcast Protection Act (RBPA) which among other things reversed the Commission rules stating that a LPFM station did not have to protect a full power or translator station's third adjacent channel, the FCC was ordered to have an independent study done of third adjacent channel interference. That report has finally been made public. For your convenience, we have provided all of the MITRE documents below. ​