Policy Implications of Two Newly Identified Modes of Interference in the FM Broadcast Band

摘要

Two unforeseen modes of interference in the FMband have come to light. First, some current models of radioreceivers can radiate intermodulation products when theyare turned off. This case study shows how that happens andraises the larger question of whether the FCC should directmanufacturers to prevent the radiation of passiveintermodulation in electronics that are connected toantennas. The second interference situation arises from thebroadcasts of a pirate radio station in proximity to an HDRadio1 transmitter on a nearby channel. In addition to thedirect interference pirate radio causes to potential listeners,this particular situation affected the operation of thelegitimate station's HD Radio transmitter. Recommendationson protecting from such corruption of transmitterperformance are presented.