AM Detuning - http://am.sitesafe.com
New FCC regulations on disturbance of AM patterns
A large change in the regulations of towers near AM stations has taken place. The FCC has released new rules on Disturbance of AM broadcast station antenna patterns. These are in 47 CFR Part 1, Subpart AA, § 1.30000 through § 1.30004 and released as FCC 13-115. The published effective date is December 5, 2013 but the implementation is delayed by the FCC pending review until early 2014. See our white paper AM Disturbance Rule Change for more information.
What are AM Detuning Services?
AM Detuning Services include the assessment and correction of pattern distortion where wireless antenna structures (i.e., towers) can unintentionally interfere with an AM broadcast station's antenna pattern. While wireless signals do not interfere with an AM station's broadcast pattern, towers can cause AM broadcast pattern disturbances. Depending on the proximity to an AM station and the height of the proposed new structure, the structure can intercept a substantial amount of energy from a nearby AM station, re-radiate it, and scatter it in other directions producing unwanted changes in the shape of the AM station's FCC-licensed coverage area.
The Code of Federal Regulations (Title 47, Volume 2, Part 22, Section 22.371) mandates that any public mobile service licensee that constructs or modifies towers in the immediate vicinity of an AM broadcast station is responsible for measures necessary to correct disturbances to the AM station's antenna pattern. The licensee must:
- Notify the AM broadcast station in advance of planned construction or modification
- Perform field measurements to document due diligence
- Install any required detuning apparatus necessary to restore proper performance of the AM station array
- Provide for continued maintenance and operation of the detuning apparatus
AM Tool Instructions