The Communications Law Blog is reporting that a rulemaking number has been assigned to SSR Communication's petition to add a new full power FM class C4.
Class C4 will be available only in "Zone II" which is the areas of the United States that excludes the northeastern United States, California south of 40 degrees latitude, Puerto Rico and the Virgin Islands. In other words, anywhere where a Class C, C1, C2 or C3 station class is currently available.
Class C4 is meant to be an upgrade from Class A. A Class C4 station will have a maxmimum facility of 12 kilowatts at 100 meters height above average terrain. In comparison, Class A is 6 kilowatts at 100 meters HAAT. This will result in a 60dBu service contour of 33.3 kilometers. A Class A station has a maximum service contour of 28.3 km and the next step up from C4 is C3 has a maximum service contour of 39.1 km.
While not mentioned in the Petition for Rulemaking, If Class C4 is created, it would create a new LPFM separation requirement in 73.807 of the Rules:
| Full Power Class | Co-Channel Required | Co Channel Fully-Spaced | First Adjacent Required | First Adjacent Fully -Spaced | Second and (when applicable) Third Adjacent Required |
| A | 67 | 92 | 56 | 56 | 29 |
| C4 | 72 | 104 | 61 | 61 | 34 |
| C3 | 78 | 119 | 67 | 67 | 40 |
SSR is also suggesting that C3 stations that do not have a service contour of at least 33.3 kilometers could be ordered to show cause on why they should not be downgraded to C4. This is normally intiated when another full power station wishes to change their facility and it conflicts with another station not running full facilities. This is a practice commonly done right now to downgrade Class C stations to C0.
REC will be evaluating the impact to LPFM and will develop position statements.
Comments on RM-11727 are due on August 18, 2014.
