NRSC Revamps AM Standards, Delivers New Guidelines

Getting busy in the AM band, the National Radio Systems Committee (NRSC) put forth revisions of NRSC-1-A, NRSC AM pre-emphasis/de-emphasis and broadcast audio transmission bandwidth specifications and NRSC-2-A emission limitation for AM broadcast transmission. The revisions are a result of the organization’s periodic standards review process. Additionally, NRSC-3 audio bandwidth and distortion recommendations for AM broadcast receivers is now out to pasture due to lack of widespread adoption. Of particular note, the AM Broadcasting Subcommittee agrees on the first bandwidth options for analog AM broadcasters guideline, NRSC-G100. This document targets broadcasters who desire to operate AM stations with audio bandwidths below 10 kHz and supplies an explanation of why lower AM bandwidth may be desirable. Also emerging is the NRSC-G200, harmonization of RDS and IBOC program service Data guideline, adopted by the Digital Radio Broadcasting Subcommittee. The guideline discusses specific text message features of the NRSC’s in-band/on-channel digital radio (NRSC-5-A) and RBDS (NRSC-4-A) standards. It defines usage that will allow broadcasters to send, and receivers to display, information independent of whether the data signal is emanating from IBOC or RDS.