This can depend on whether the other station is located in the United States, Canada or Mexico.
Domestic (other station is in the USA)
The Making Appropriations For The District of Columbia Act of 2001 (Pub L. 106-553) which is also known as the Radio Broadcast Preservation Act in Section 632(a)(1)(A) requires the FCC to establish rules to prescribe minimum distance separations for third-adjacent channels (as well as for co-channels, and first- and second-adjacent channels). This statute mandates that the FCC uses distance separation instead of contour overlap for LPFM stations to protect full-power stations.
In 2010 with the passing of the Local Community Radio Act, the RBPA was amended (through LCRA Section 2) to state that the FCC shall modify its rules authorizing the operation of LPFM stations, as proposed in MM Docket 99-25, to prescibe protection for co-channels and first- and second-adjacent channels. This provision would open the door to allow for the FCC to waive third-adjacent channel separation. In section 3 of the LCRA, it seals the deal on third-adjacent by stating in 3(a) that the FCC shall modify the rules to eliminate third-adjacent channel minimum spacing requirements between LPFM and "full-service FM stations, FM translator stations and FM booster stations."
However, in Section 3(b)(1) of the LCRA, Congress orders that the FCC "shall not amend the rules to reduce the minimum co-channel and first- and second-adjacent channel distance separation requirements on the date of enactment of [the LCRA] between LPFM stations and "full-service FM stations". 3(b)(2) addresses second-adjacent channel waivers.
Based on a reading of the LCRA, it would be suggested that the FCC can not waive co-channel and first-adjacent channel to any distance less than that shown in §73.807(a). REC does feel that there are couple of key points about the way that Congress wrote the LCRA and how it can be interpreted (and use these arguments at your own risk):
- Section 3(b)(1) uses the language "in effect on the date of enactment of this Act". The LCRA was signed by President Obama on January 4, 2011. In the Sixth Report and Order of MM Docket 99-25, the FCC eliminated the LP-10 service from the rules. No LP-10 stations were ever authorized. The Sixth R&O was issued on November 30, 2012. This means that at the time when the LCRA was signed by the President, the LP-10 tables were still on the books and therefore was "in effect" on the date of enactment of the LCRA. In response to the LPFM.AG proposed rulemaking (RM-11753), REC proposed "Plan B" which consisted of a combination of contour overlap and the minimum LP-10 distance separation requirements. This would be similar to the alternate protction method available to commercial FM stations under §73.215. REC would not necessarily recommend asking for a waiver using interpretation of the LCRA mainly due to an interpretation of the LCRA that states it must be codified in the rules first.
- Section 3(b)(1) also uses the language "between low-power FM stations and full-service FM stations" in reference to the rules where the FCC can't amend the rules to reduce minimum spacing (in effect at the enactment of the LCRA). We go back to 3(a)(2) where the FCC eliminates the spacing requirement for third-adjacent channel stations and it states the elimination applies to "full-service FM stations, FM translator stations, and FM booster stations." Since FM translators and boosters are not mentioned in 3(b)(1) which prohibits reducing the distances in §73.807, it can be interpreted that LPFM stations should be permitted to operate at distances less than those permitted under §73.807 in respect to FM translators and FM boosters only. REC feels that there is justification under the current rules to ask for a waiver of §73.807 in respect to a co-channel or first-adjacent channel FM translator as long as a showing can be made that the interfering contour of the LPFM station does not overlap the protected contour of the FM translator. Again, use this at your own risk. The FCC has already denied requests citing the RBPA, but we feel that if a LCRA argument is made as part of the waiver, it can potentially carrry some weight. Again, at your own risk.
Foreign stations (Canada and Mexico)
There is case law where it has been interpreted that the RBPA and LCRA do not apply to foreign stations. There are differing international agreements between Canada and the USA and between Mexico and the USA. There have already been a couple of cases where distance to foreign stations has been waived upon a showing of protection. In one case, it involved a directional antenna. It is highly recommended that you contact REC for assistance in this situation.