-
1. What is frequency coordination?
Basically, it is a form of voluntary participation in an organized program intended to keep
interference between repeaters and their users to a minimum. To do this, repeater sponsors work
with their local frequency coordinator who maintains a database of repeater frequencies in active
use (as well as new repeaters which are under construction but may not yet be in operation). The
frequency coordinator assists the repeater sponsor in selecting operating frequencies (and
perhaps other technical details) which will, hopefully, be compatible with other existing repeaters.
Back to FAQ Index
-
2. Who is a frequency coordinator?
Your Amateur Radio frequency coordinator is, first, a volunteer. In the SouthEastern Repeater
Association, he is an individual who probably lives in your community or region of the state.
Your coordinator in other areas of the country may be an organization of volunteers who are
recognized by the Amateur Radio community as their "coordinator". He/they might participate in
the program because they are interested in either the technical or the political aspects of
coordination, but they all do it as a way of putting something back into Amateur Radio. These
days, no coordinator worth his salt is in it for the ego! It's too much work! But all coordinators do
get some form of self satisfaction out of doing the job, or they wouldn't bother.
Back to FAQ Index
-
3. Who benefits from frequency coordination?
In a nutshell, everyone does. Sponsors of existing coordinated repeaters are assured that the
frequency coordinator will attempt to protect their repeaters and their users from interference
caused by new repeaters. Likewise, sponsors of proposed new machines will get knowledgeable
assistance from the frequency coordinator in selecting frequencies for their machines, so that
they and their users can feel confident that their new operation will not adversely affect any
existing repeaters, and they should experience little interference on their new machines.
Back to FAQ Index
-
4. How does frequency coordination work?
In order to make a recommendation, the frequency coordinator needs some data about the
proposed new repeater, such as its location, antenna height, ground elevation above sea level,
transmit power, etc. These items all affect, to one degree or another, the repeater's area of
coverage. The frequency coordinator will review the data on the new repeater. Then in
conjunction with the data in his database, he may assist the applicant in finding an optimum
frequency pair.
Most frequency coordinators will consult with the sponsors of nearby co-channel
(same frequency) and adjacent-channel repeaters, and with his adjacent-area counterparts, to
make sure there are not any valid objections to the new repeater. This way, sponsors of existing
repeaters are given the opportunity to look out for their own interests. Once a new coordination
is issued, there is a six month construction period to get the new machine on the air. If it's not on
by this deadline, the coordination is allowed one additional six-month period (upon written
request), after which the coordination is subject to cancellation. This keeps the coordinator's
database from filling up with "paper" repeaters.
Back to FAQ Index
-
5. Is frequency coordination required?
No. Participation in a frequency coordination program is strictly voluntary. No Amateur Radio
frequency coordinator has any "authority" to tell a repeater sponsor what he can, or cannot do.
However, the Federal Communications Commission (FCC) and the amateur community
has recognized that participation in a frequency coordination
program by repeater sponsors is in the best interests of all Amateurs. Therefore, FCC rules
(Part 97.205c) have been adopted which state that the sponsor of an uncoordinated repeater
bears the primary responsibility for curing any interference between his repeater and another
repeater which is coordinated. Likewise, the sponsor of an uncoordinated machine cannot expect
much help from his area frequency coordinator.
Back to FAQ Index
-
6. How can a coordination be canceled?
1. If a proposed new repeater never gets on the air or if an existing repeater goes off the air, the
coordination may be subject to cancellation after a limited amount of time (not in operation after
6 months or more from date of coordination)
2. If any of the primary parameters which affect a repeater's coverage area are changed by the
sponsor, the coordination can be voided. For instance if it gets moved to a different location, of if
the antenna height or transmitter power are changed, the changes would affect the coverage
area, possibly creating new interference problems for the repeater's neighbors.
Some coordinators require sponsors to file periodic up-dates in order to retain their
coordinations. Others rely on their own monitoring efforts to keep abreast of activity.
Back to FAQ Index
-
7. Are other Amateur Radio stations also coordinated?
Yes. In addition to repeaters, the frequency coordinator also coordinates other operations
associated with repeaters, such as links between a repeater's
remote receivers and the main site, etc. In addition, they can also assist in your understanding
of the many interrelated frequency rules that apply to repeaters, remote-bases, links,
remote control, auto-patches, cross-band operation, and so forth.
Back to FAQ Index
-
8. What kind of problems do frequency coordinators have?
Nowadays there are probably 2 main problem areas.
1. First are problems created by the few uncoordinated machines which pop up from time to
time.
2. Second, are problems caused by the proliferation of dual-band transceivers with built-in
cross-band repeat capability. Unfortunately, a poor choice of frequencies can cause interference
problems which may go totally unknown to the user of the dual-band radio. SERA has published
a list of suggested frequencies for use with mobile cross-band repeaters.
There are a small number of uninformed operators who abuse cross-band repeater capabilities
causing unintentional, but sometimes even malicious, interference.
Other problems are caused when the frequency coordinator is not apprised of changes to
existing repeaters, changes of sponsor's mailing address, etc.
Back to FAQ Index
-
9. What other activities do frequency coordinators conduct?
Many coordinators are involved in "band-planning" or "spectrum management" efforts, often in
association with adjacent-area coordinators, other special-interest groups, or the ARRL's
Spectrum Management Committee, Digital Advisory Committee, and Membership Services
Committee. Different special-interest groups include the packet community, the DX Cluster
community, weak-signal/SSB/CW interests, FM simplex users, ATV'ers, etc. All of these other
interest groups need to be considered when "band-plans" are being developed or revised, so
frequency coordinators need to keep them in mind as they conduct their spectrum management
effort. Band-planning/spectrum management cannot be done in a vacuum! Good familiarity with
the frequency coordinator Rules is helpful here, since repeater, remote-control, link and remote-
base operation is prohibited in some parts of the Amateur HF, VHF and UHF bands.
Many coordinators maintain a list of technical experts who are available to assist repeater sponsors in
resolving technical problems. They also maintain a list of Amateurs with the capability and
expertise in finding interference sources, both from spurious emissions, as well as malicious
interference. Also some coordinators maintain, or have access to, a fairly extensive library of
technical information on equipment, system designs, and maintenance. These resources are all
available to the sponsors of all coordinated repeaters in the area.
Back to FAQ Index
-
10. Who is our local coordinator?
The States of Georgia, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee, and
the majority of Virginia and West Virginia, are coordinated by the SouthEastern Repeater
Association, Inc. (SERA), an organization which was founded in 1971 by a group of North
Carolina repeater owners. The SERA is divided into eight districts comprising these eight states,
and divided into areas by the director and usually the vice director. Usually the director and vice
director are the frequency coordinators for those areas in your state. They are hams (like
yourself) who love ham radio and have volunteered to serve the amateurs of their area by
performing the thankless duties of frequency coordinator. You will find your coordinator listed
on the DISTRICT page of this web site.
The SouthEastern Repeater Association has recently acquired a multi-site license for a professional
grade communications engineering software package which will enable coordinators to make a much more
thorough analysis of the potential coverage of every proposed coordination. Path analysis, coverage
maps, and other sophisticated tools are now available to the coordinator to help resolve potential
interference and questions as to anticipated coverage when there are potential problems with
co-channel and adjacent-channel repeaters. As far as we know, the SERA is the only nonprofit
coordination organization anywhere with the sophisticated capabilities which this system offers.
Back to FAQ Index
Portions provided, with
permission, from T-MARC
If you have any comments, problems, or suggestions about our web site,
please e-mail them to
Alex Hedrick, N8FWL.
