The following table lists the FM spacing standards for U.S. stations in the Mexican Border Zone (within 320 km of the border). These spacings are taken from the August 1992 revision of the Agreement Between the Government of the United States of America and the Government of the United Mexican States Relating to the FM Broadcasting Service in the Band 88 - 108 MHz. The revised separation requirements were adopted into 47 CFR Section 73.207(b)(3) by the Amendment of Section 73.207(b) of the Commission's Minimum Distance Separations To Mexican Broadcast Stations, FCC 97-272, 61 FR 50256 (1997) [ Text | Word Perfect 5.1  ].

For the purposes of the table which follows:

• U.S. or Mexican Class A assignments [stations] or allotments which have been notified internationally as Class A are limited to a maximum of 3.0 kW ERP at 100 meters HAAT, or the equivalent.

• U.S. or Mexican Class A assignments or allotments which have been notified internationally as Class AA are limited to a maximum of 6.0 kW at 100 meters HAAT, or the equivalent.

• U.S. Class C3 assignments or allotments are considered Class B1.

• U.S. Class C2 assignments or allotments are considered Class B.

• Class C1 assignments or allotments assume maximum facilities of 100 kW ERP at 300 meters HAAT. However, U.S. Class C1 stations may not, in any event, exceed the domestic U.S. limit of 100 kW ERP at 299 meters HAAT, or the equivalent.

  U.S. Class C0 (C-zero) assignments or allotments are considered Class C.

Noncommercial Educational FM stations in the Mexican Border Zone must also adhere to these separations (see 47 CFR Section 73.507). Acceptable applications for noncommercial stations will be referred to Mexico for concurrence after review.

In some cases, a station or allotment may be sought to operate at a distance less than those separations specified below. Such requests will require a showing that interference is avoided within the protected contours of the stations involved, with the pertinent Mexican stations being assumed at the maximum facilities permitted for the station class, and assuming that the Mexican station's protected service contour is the 60 dBu (1.0 mV/m) F(50,50) contour for Class A, AA, C1, and C stations; the 57 dBu (0.7 mV/m) for Class B1 stations; and 54 dBu (0.5 mV/m) for Class B stations. Such applications or petitions for rulemaking will require additional processing time while concurrence from Mexico is sought.