WSJ Reports on AM IBOC Interference

WSJ Reports on AM IBOC Interference
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AM interference from digital radio is in the Wall Street Journal. The paper reports that some AMs that have elected to remain analog are experiencing adjacent-channel interference from neighboring AMs that have gone digital.
Anecdotally, reports of such interference on AM from new digital signals have been circulating in the industry for some time and we've reported on those.
The WSJ article cites a listener in Elkridge, Md., who has had trouble tuning into WTRI(AM), 1520 kHz, since WTOP, at 1500 kHz in Washington, went HD Radio about a year ago.
In most cases, the interference is confined outside the FCC-protected coverage area, the account reports, agreeing with NRSC sources, quoted here in the past, who have tested the Ibiquity system. They and the FCC have known there would be some interference caused by IBOC and have maintained the levels would be acceptable.
FCC Audio Division Chief Peter Doyle is quoted by the Journal as explaining that broadcasters chose to go digital with Ibiquity's technology because it doesn't require new spectrum and that the advantages more than outweigh the shortcomings. Adding digital service is one way to combat the problem, although some small stations can't afford the cost.


IBOC Interference

Anything greater than a 3 dB increase in IBOC power will not only cause problems for other broadcasters on first-adjacent and co-channel frequencies, but will also have a great potential for increased self-interference for stations.

Rochester Station Says IBOC Interferes

In what is thought to be the first AM nighttime IBOC interference complaint filed with the FCC, Radio Livingston Ltd., licensee of WYSL in Upstate New York, claims that adjacent-channel IBOC noise from WBZ in Boston is interfering with its daytime and nighttime signals.