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.
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.
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.
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.
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.
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.
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.
8. What kind of problems do frequency coordinators have?
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.
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.
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.
Portions provided, with permission, from T-MARC