NABOn May 11, the National Association of Broadcasters (NAB) filed comments with the FCC supporting a petition to allow AM stations to broadcast an all-digital AM signal on a voluntary basis.

In late March, Texas-based Bryan Broadcasting filed a Petition for Rulemaking asking the commission to initiate a proceeding to authorize the MA3 all-digital mode of HD Radio for any AM station that chooses to do so.

Permitting such modernization would “give AM broadcasters a needed innovative tool with which to compete” without harming others in the spectrum ecosystem, it wrote.

In its comments, the NAB said that “we agree with the Petitioner that all-digital AM service will allow broadcasters to provide substantially improved sound quality that could help AM stations to retain and attract listeners in the increasingly competitive audio marketplace. Experimental testing and real-world implementation of all-digital AM, and industry interest in launching all-digital AM
services all support further consideration of rules to facilitate broadcasters’ voluntary transition to all-digital AM service.

Radio World notes that “All HD Radio receivers in the market that have AM functionality would be able to receive such all-digital signals. But legacy AM receivers would not, which has long been a barrier to serious discussion of all-digital. Now, some observers say, the availability of FM translators for AM licensees has made something that once seemed unthinkable at least worth discussing.”

Currently there is one station in the country that has been experimenting with an all-digital AM signal, under FCC experimental authority. Hubbard Radio’s WWFD-AM (Frederick, MD) has turned off its analog signal while remaining in all-digital mode.  NAB says that it understands that WWFD’s digital signal is robust and far more listenable than analog service. Hubbard has said it received encouraging feedback from listeners and informed NAB that it would consider transitioning additional AM stations to all-digital broadcasting, if permitted.