The FCC is taking comments on NAB’s report on how stations might use separate antennas for the FM analog and digital signals transmitted with HD Radio. An ad hoc NAB committee submitted a report this summer to the commission, with several suggestions for criteria under which stations could use separate antennas and thus save money and increase efficiency for HD Radio implementation.
FM stations going on the air now with the hybrid analog/digital signals are restricted to a single antenna because when the commission authorized IBOC, it had no data on whether using separate antennas could be done without causing interference to the host or neighboring stations.
NAB stated that separate antennas for digital transmission would work if certain criteria were met: The digital transmission must use a licensed auxiliary antenna; The auxiliary antenna must be within three seconds of latitude and longitude of the main antenna; and The height above average terrain of the auxiliary antennas must be between 70 and 100 percent of the height above average terrain of the main antenna.
The report also recommends that the commission authorize use of antennas specially designed with interleaved or stacked elements for analog and digital signals.
The FCC seeks comments on the report (MM Docket 99-325) by Jan. 8 and replies by Jan. 23.
Tell the FCC What You Think About Separate Antennas for FM IBOC
Tell the FCC What You Think About Separate Antennas for FM IBOC
