§  74.1203   Interference.

   (a) An authorized FM translator or booster station will not be
   permitted to continue to operate if it causes any actual interference
   to:

   (1) The transmission of any authorized broadcast station; or

   (2) The reception of the input signal of any TV translator, TV booster,
   FM translator or FM booster 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:

   (i) The required minimum number of valid listener complaints as
   determined using Table 1 of this section and defined in § 74.1201(k) of
   this part;

   (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 methodology set
   out in § 74.1204(b).

   Table 1 to § 74.1203(a)(3)
   Population within protected contour Minimum
   listener
   complaints
   required
   for
   interference
   claim
   1-199,999 6
   200,000-299,999 7
   300,000-399,999 8
   400,000-499,999 9
   500,000-999,999 10
   1,000,000-1,499,999 15
   1,500,000-1,999,999 20
   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.

   [ 55 FR 50693 , Dec. 10, 1990, as amended at  60 FR 55484 , Nov. 1, 1995;
    84 FR 27740 , June 14, 2019;  86 FR 13663 , Mar. 10, 2021]