It’s High Time for an AM Update
Ben Dawson and Ron Rackley’s commentary, “Take
a Fresh Look at AM Rules” (Radio World, March 27), I
wholeheartedly agree that the FCC rules governing AM broadcast need
refinement, since they were crafted at a time when the landscape of
radio was very different. In many communities back then, AM was the
primary source of broadcast news and information.
were more sensitive than those of today. There were no computers,
DSL, BPL and solid-state devices to contribute to an elevated noise
floor. Auto radios had vertical antennas, which were more efficient
than today’s stealthier counterparts. Population was distributed
differently. Directional arrays were located wherever possible, to
serve an audience that is today more geographically diverse.
nulls or minimas may have once fallen over fields, the pastures of
yesterday have evolved into condos, strip malls or populated areas.
In some cases, transmitter site real estate has appreciated in value
such that relocating a tower is a wise business move.
the above was in sight when the FCC rules were written.
there’s the fact that AM music formats began to migrate to FM,
cassette players, CD changers, satellite radio, Internet radio, iPod,
etc. And USB interfaces found their way into automobile radios. And
windshield and other less-efficient antenna designs prevail, as do
less sensitive, narrowband receivers.
these pose a disadvantage to AM broadcasters.
required annual emissions measurements, NRSC pre-emphasis standards,
expanded band and other technologies have not significantly increased
AM listenership. AMAX standard receivers were never mandated in the
that want or need to relocate their transmitter facilities find
themselves bound by restrictions that don’t help but hinder serving
the public. For example, a station that wishes to diplex with another
may not be able to do so given the requirement for city of license
coverage. Another may wish to employ a radiator that does not meet
the minimum efficiency requirements. The use of such a radiator may
be the sole option that satisfies neighbors and the local zoning
system requirements often prevent the use of a site where a system of
lesser or alternate design may permit the move and provide adequate
stations now benefit from the use of modern computer modeling tools
and vector analysis instruments. The AM broadcast service is not
unlike an old commercial building with modern tenants. The utility
infrastructure was not designed to accommodate computers, server
rooms with air conditioning, and uninterruptible power sources.
retrofit is required to meet contemporary needs. The FCC needs to
revisit and examine rules pertaining to the AM service, and apply
revisions that will help maintain and boost its ability to serve
today’s and tomorrow’s needs.
Osenkowsky is a radio engineering consultant in Brookfield, Conn.,
and a longtime RW contributor. He has been in the radio broadcast
industry since 1975. Opinions are his own.