47 CFR § 74.1203 - Interference.
(1) The transmission of any authorized broadcast station; or
(3) The direct reception by the public of the off-the-air signals of any full-service station or previously authorized secondary station. Interference will be considered to occur whenever reception of a regularly used signal is impaired by the signals radiated by the FM translator or booster station, regardless of the channel on which the protected signal is transmitted; except that no listener complaint will be considered actionable if the alleged interference occurs outside the desired station's 45 dBu contour. Interference is demonstrated by:
(ii) A map plotting the specific location of the alleged interference in relation to the complaining station's 45 dBu contour;
(iii) A statement that the complaining station is operating within its licensed parameters;
(iv) A statement that the complaining station licensee has used commercially reasonable efforts to inform the relevant translator licensee of the claimed interference and attempted private resolution; and
(v) U/D data demonstrating that at each listener location the undesired to desired signal strength exceeds −20 dB for co-channel situations, −6 dB for first-adjacent channel situations or 40 dB for second- or third-adjacent channel situations, calculated using the Commission's standard contour prediction methodology set out in § 73.313.
Table 1 to § 74.1203(a)(3)
|Population within protected contour||Minimum
|2,000,000 or more||25|
|LPFM stations with fewer than 5,000||3|
(b) If interference cannot be properly eliminated by the application of suitable techniques, operation of the offending FM translator or booster station shall be suspended and shall not be resumed until the interference has been eliminated. Short test transmissions may be made during the period of suspended operation to check the efficacy of remedial measures.
(c) An FM booster station will be exempted from the provisions of paragraphs (a) and (b) of this section to the extent that it may cause limited interference to its primary station's signal, provided it does not disrupt the existing service of its primary station or cause such interference within the boundaries of the principal community of its primary station.
(d) A fill-in FM translator operating on the first, second or third adjacent channel to its primary station's channel will be exempt from the provisions of paragraphs (a) and (b) of this section to the extent that it may cause limited interference to its primary station's signal, provided it does not disrupt the existing service of its primary station or cause such interference within the boundaries of the principal community of its primary station.
(e) It shall be the responsibility of the licensee of an FM translator or FM booster station to correct any condition of interference which results from the radiation of radio frequency energy by its equipment on any frequency outside the assigned channel. Upon notice by the Commission to the station licensee that such interference is being caused, the operation of the FM translator or FM booster station shall be suspended within three minutes and shall not be resumed until the interference has been eliminated or it can be demonstrated that the interference is not due to spurious emissions by the FM translator or FM booster station; provided, however, that short test transmissions may be made during the period of suspended operation to check the efficacy of remedial measures.