Click to see specific topics:   FM The FM radio service is made up of 20 non-commercial educational (NCE) channels (201 through 220, made up of frequency band 88.1 to 91.9 MHz) and 80 commercial channels (221 through 300, made up of frequency band 92.1  to 107.9 MHz.)  FM channels have a frequency bandwidth of 200 kHz (0.2 MHz.)  The standard FM radio service is coverage by Sections 73.200 through 73.599 of the FCC rules. All FM stations are assigned a "station class" that restricts its size by controlling the maximum power and maximum antenna height allowed for each station classification.  The FM station classes are as follows: The FCC assigns FM stations by allotting a FM channel and FM station class to a city or town (referred to as a FM community of license).  Such assignments are typically made only at the request of the public, and only upon a demonstration of availability based on FCC Rules that protect the FM service from interference.  A FM community of license, its assigned channel and its assigned station class are together considered an "FM Allotment," and a list of all vacant FM allotments are included in Section 73.202 of the FCC Rules.  For example, one of the first listings is Abbeville, AL, 232C3 (which stands for channel 232, station class C3). A new commercial FM allotment is typically requested by a formal "Notice of Proposed Rulemaking" filing that demonstrates the availability of the FM allotment.  A reference location for the FM allotment (obviously near to the community of license that is being requested) is used to demonstrate that the FM allotment will meet the distance separation requirements to all co-channel and adjacent-channel stations requiring protection in accordance to the FCC Rules.  For the most part, commercial FM interference protection is controlled by requiring the stations meeting spacing dependent upon the FM station classes.  The required separation distances are listed in Section 73.207 of the FCC Rules.  (The NCE and commercial FM services have different FCC Rules and protection standards.  The NCE service is controlled more so using actual interference calculations as opposed to distance separation requirements.)  A new commercial FM allotment will typically be awarded by a FCC auction.  DeLawder Communications, Inc. can help evaluate FM stations and allotments, as well as study potential coverage improvements (i.e. station class upgrades) that may be available.  DC will also prepare the engineering portion of the applications and FCC rulemaking proposals that must be submitted to the FCC.   Important FM Service Points 1.  Most vacant FM Allotments are Class A allotments and/or propose to serve small to medium sized communities. 2.  Class upgrades are an important method for improving a FM station (or allotment).  Before considering purchase of a FM station or before bidding in a FM auction, one should know the upgrade potential of a station (or allotment). 3.  The FCC Rules provide exceptions to the spacing protection requirements, allowing "short-spacings" based on directional antenna use and detailed signal propagation studies. 4.  The maximum height above average terrain (HAAT) can be exceeded for a particular station class (as is the case for various mountaintop sites), however, the maximum allowable effective radiated power (ERP) is correspondingly reduced so that the predicted maximum coverage for the station class is not exceeded.   Low Power FM (LPFM) On January 20, 2000 the FCC established the low power FM (LPFM) service, which is available to noncommercial educational entities and Traveler's Information Station entities, but not to commercial operations or individuals.  The maximum effective radiated power (ERP) for these stations is 100 watts (with a typical service range of 3 to 5 miles.)  LPFM stations are not protected from interference by full service FM stations.    Click (Here) for an easy to print downloadable PDF brochure of all our services.