of a Radio World series in which we share industry
opinions about AM revitalization.
I offer tech tips but this time I want to express a personal opinion
on a topic important to me.
it is a goal of the Federal Communications Commission to reduce
regulatory and financial burden on AM broadcasters, then here is one
way to help: Modify FCC rule 73.1590(a)(6) requiring annual occupied
bandwidth and RF harmonic radiation measurements on AM stations,
known as AM NRSC measurements.
might remember that NRSC is the National Radio Systems Committee,
which created standards for occupied bandwidth on AM and FM stations.
The FCC turned those standards into rules.
propose to exempt AM stations that use solid-state transmitters from
the existing requirement to make annual measurements.
rules were written when vacuum tubes were often used in transmitter
designs. Tube performance degrades with time. The result is that
tubes must be replaced every year or two in order to maintain
operating specifications. Beyond that time in service, an AM
transmitter may not be able to comply with FCC rules for occupied
bandwidth, which results in interference to other stations on the
dial. In the case of FM transmitters, a weak/soft tube does not
normally cause bandwidth issues.
AM stations continuing to use tube transmitters, this annual
requirement should still apply. The requirement that all AM and FM
licensees keep their equipment in compliance with FCC rules should
stay in place, regardless of which transmitter design they use.
in any AM or FM equipment that could alter the occupied bandwidth
should automatically trigger the requirement to do measurements to
assure compliance with FCC rules. A 30-day window to make successful
compliance measurements sounds appropriate to me. The equipment
change could be as simple as replacing an audio processor with a
different model number.
This rule revision
would bring AM stations into the same level of scrutiny that FM
stations should meet; I feel my suggested changes will also assure FM
that any change in equipment lineup could unwittingly cause bandwidth
problems. The only way to be sure the station is FCC legal is to do
the procedure for AM and FM stations should be written to require
listing model numbers of studio transmitter links, audio processors
and transmitters. (Serial numbers are not important.) In the case of
FM stations, audio processors, stereo generators, RDS/RBDS
generators, studio transmitter links and transmitters should be
essence, anything capable of controlling or changing occupied
bandwidth should be documented.
report would not be placed in a public file. Instead it would go into
the station’s engineering file, which is not seen by the public. No
change there. In that way, a station’s “custom lineup” of audio
processing would not be revealed to competitors.
FM rule 73.1590(d) regarding measurement data needs to be modified to
strike the words “for a period of 2 years, and on request must be
made available during that time to duly authorized representatives of
the FCC.” This re-written rule would require measurement data to be
kept on hand until superseded by a newer report. It is documented
proof of legal operation.
FCC inspector or mock inspector would request this report when
visiting a station. He or she would check to see if the same
equipment is employed, even if it is years later. Any report that did
not have this data would be invalid.
speaking, my proposal would mean that all or most stations would need
to perform a new set of measurements based on these criteria in the
immediate future. Again, any changes in the equipment lineup should
require a new set of measurements to assure FCC compliance.
another note, station technical consultants need to be vigilant in
watching for new transmitter sites or changes to existing transmitter
sites within five miles or so of the transmitters they are watching
after. A new onsite or offsite transmitter in the AM or FM band might
create mixing products that could render the station illegal under
annual measurements are not needed, in my opinion. Just watching
after the store, so to speak, is what is necessary.
perspective, technology has improved to make equipment more reliable
and trouble-free. FCC rules have been modified in the past to keep
up, even if they did lag a bit from reality. Stations were required
to read and log all operating parameters every half hour up until
about 40 years ago. Monthly carrier frequency measurements were
required until about 30 years ago, as were annual audio proof of
don’t even have operator licenses anymore. Now is the time for the
FCC to make the changes I outlined. It is good for the radio
broadcast industry and makes perfect sense.
on this or any article. Write to firstname.lastname@example.org.
Persons, WØMH, is a Certified Professional Broadcast Engineer and
has more than 30 years’ experience. His website is www.mwpersons.com.