[Code of Federal Regulations]
[Title 47, Volume 2]
[Revised as of October 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR74.1204]

[Page 503-505]
 
                       TITLE 47--TELECOMMUNICATION
 
        CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION (CONTINUED)
 
PART 74_EXPERIMENTAL RADIO, AUXILIARY, SPECIAL BROADCAST AND OTHER PROGRAM 
 
  Subpart L_FM Broadcast Translator Stations and FM Broadcast Booster 
                                Stations
 
Sec.  74.1204  Protection of FM broadcast, FM Translator and LP100 stations.

    (a) An application for an FM translator station will not be accepted 
for filing if the proposed operation would involve overlap of predicted 
field contours with any other authorized commercial or noncommercial 
educational FM broadcast stations, FM translators, and Class D 
(secondary) noncommercial educational FM stations; or if it would result 
in new or increased overlap with an LP100 station, as set forth:
    (1) Commercial Class B FM Stations (Protected Contour: 0.5 mV/m)

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         Frequency separation             Interference contour of proposed translator station        Protected contour of commercial Class B station
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Co-channel............................  0.05 mV/m (34 dBu).....................................  0.5 mV/m (54 dBu)
200 kHz...............................  0.25 mV/m (48 dBu).....................................  0.5 mV/m (54 dBu)
400 kHz/ 600 kHz......................  50.0 mV/m (94 dBu).....................................  0.5 mV/m (54 dBu)
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    (2) Commercial Class B1 FM Stations (Protected Contour: 0.7 mV/m)

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         Frequency separation             Interference contour of proposed translator station        Protected contour of commercial Class B1 station
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Co-channel............................  0.07 mV/m (37 dBu).....................................  0.7 mV/m (57 dBu)
200 kHz...............................  0.35 mV/m (51 dBu).....................................  0.5 mV/m (57 dBu)
400 kHz/ 600 kHz......................  70.0 mV/m (97 dBu).....................................  0.7 mV/m (57 dBu)
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    (3) All Other Classes of FM Stations (Protected Contour: 1 mV/m)

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         Frequency separation                 Interference contour of proposed translator                 Protected contour of any other station
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Co-channel............................  0.1 mV/m (40 dBu)......................................  1 mV/m (60 dBu)
200 kHz...............................  0.5 mV/m (54 dBu)......................................  1 mV/m (60 dBu)
400 kHz/ 600 kHz......................  100 mV/m (100 dBu).....................................  1 mV/m (60 dBu)
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    (4) LP100 stations (Protected Contour: 1 mV/m)

[[Page 504]]



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         Frequency separation             Interference contour of proposed translator  station           Protected contour of LP100 LPFM station
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Co-channel............................  0.1 mV/m (40 dBu)......................................  1 mV/m (60 dBu)
200 kHz...............................  0.5 mV/m (54 dBu)......................................  1 mV/m (60 dBu)
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    Note to paragraph (a)(4):
    LP100 stations, to the purposes of determining overlap pursuant to 
this paragraph, LPFM applications and permits that have not yet been 
licensed must be considered as operating with the maximum permitted 
facilities. All LPFM TIS stations must be protected on the basis of a 
nondirectional antenna.

    (b) The following standards must be used to compute the distances to 
the pertinent contours:
    (1) The distances to the protected contours are computed using 
Figure 1 of Sec.  73.333 [F(50,50) curves] of this chapter.
    (2) The distances to the interference contours are computed using 
Figure 1a of Sec.  73.333 [F(50,10) curves] of this chapter. In the 
event that the distance to the contour is below 16 kilometers 
(approximately 10 miles), and therefore not covered by Figure 1a, curves 
in Figure 1 must be used.
    (3) The effective radiated power (ERP) to be used is the maximum ERP 
of the main radiated lobe in the pertinent azimuthal direction. If the 
transmitting antenna is not horizontally polarized only, either the 
vertical component or the horizontal component of the ERP should be 
used, whichever is greater in the pertinent azimuthal direction.
    (4) The antenna height to be used is the height of the radiation 
center above the average terrain along each pertinent radial, determined 
in accordance with Sec.  73.313(d) of this chapter.
    (c) An application for a change (other than a change in channel) in 
the authorized facilities of an FM translator station will be accepted 
even though overlap of field strength contours would occur with another 
station in an area where such overlap does not already exist, if:
    (1) The total area of overlap with that station would not be 
increased:
    (2) The area of overlap with any other station would not increase;
    (3) The area of overlap does not move significantly closer to the 
station receiving the overlap; and,
    (4) No area of overlap would be created with any station with which 
the overlap does not now exist.
    (d) The provisions of this section concerning prohibited overlap 
will not apply where the area of such overlap lies entirely over water. 
In addition, an application otherwise precluded by this section will be 
accepted if it can be demonstrated that no actual interference will 
occur due to intervening terrain, lack of population or such other 
factors as may be applicable.
    (e) The provisions of this section will not apply to overlap between 
a proposed fill-in FM translator station and its primary station 
operating on a first, second or third adjacent channel, provided That 
such operation may not result in interference to the primary station 
within its principal community.
    (f) An application for an FM translator station will not be accepted 
for filing even though the proposed operation would not involve overlap 
of field strength contours with any other station, as set forth in 
paragraph (a) of this section, if the predicted 1 mV/m field strength 
contour of the FM translator station will overlap a populated area 
already receiving a regularly used, off-the-air signal of any authorized 
co-channel, first, second or third adjacent channel broadcast station, 
including Class D (secondary) noncommercial educational FM stations and 
grant of the authorization will result in interference to the reception 
of such signal.
    (g) An application for an FM translator or an FM booster station 
that is 53 or 54 channels removed from an FM radio broadcast station 
will not be accepted for filing if it fails to meet the required 
separation distances set out in Sec.  73.207 of this chapter. For 
purposes of determining compliance with Sec.  73.207 of this chapter, 
translator stations will be treated as Class A stations and booster 
stations will be treated the same as their FM radio broadcast station 
equivalents. FM radio broadcast station equivalents will be determined 
in accordance with Sec. Sec.  73.210 and 73.211 of

[[Page 505]]

this chapter, based on the booster station's ERP and HAAT. Provided, 
however, that FM translator stations and booster stations operating with 
less than 100 watts ERP will be treated as class D stations and will not 
be subject to intermediate frequency separation requirements.
    (h) An application for an FM translator station will not be accepted 
for filing if it specifies a location within 320 kilometers 
(approximately 199 miles) of either the Canadian or Mexican borders and 
it does not comply with Sec.  74.1235(d) of this part.
    (i) FM booster stations shall be subject to the requirement that the 
signal of any first adjacent channel station must exceed the signal of 
the booster station by 6 dB at all points within the protected contour 
of any first adjacent channel station, except that in the case of FM 
stations on adjacent channels at spacings that do not meet the minimum 
distance separations specified in Sec.  73.207 of this chapter, the 
signal of any first adjacent channel station must exceed the signal of 
the booster by 6 dB at any point within the predicted interference free 
contour of the adjacent channel station.
    (j) FM translator stations authorized prior to June 1, 1991 with 
facilities that do not comply with the predicted interference protection 
provisions of this section, may continue to operate, provided that 
operation is in conformance with Sec.  74.1203 regarding actual 
interference. Applications for major changes in FM translator stations 
must specify facilities that comply with provisions of this section.

[55 FR 50694, Dec. 10, 1990, as amended at 56 FR 56170, Nov. 1, 1991; 58 
FR 42025, Aug. 6, 1993; 65 FR 7649, Feb. 15, 2000; 65 FR 67304, Nov. 9, 
2000; 65 FR 79780, Dec. 20, 2000]