Ham Radio Repeater Frequency Coordination
Learn one of the most important steps to putting a new repeater on the air!
There are thousands of ham radio repeater installations on the air across the U.S. in just about every location you can imagine. Some are installed in backyards on short towers, others are located on tall buildings, on water tank towers, shared with area police and fire department towers, and many are installed at commercial broadcast radio and TV station locations using very very high towers. Others are even on top of high mountains that serve a very wide area.
In very populated states and cities like California, Florida, New York and other major highly populated locations, just putting repeaters on the air on just any random frequency without frequency coordination within a ham band, would cause immense interference between them.
If every ham radio repeater was not frequency "coordinated" then many would be unusable, especially in times of emergency due to many being on the same frequencies.
As you should know, the repeater antenna is the most important part of any ham radio station so it should be installed as high as possible for better coverage over a wider area. This increases the repeater range usually but if the respective repeater that is using that antenna is on a transmit frequency that happens to be on or near the input frequency of another nearby repeater, then interference to the other repeater may result.
So to help remedy this, frequency coordination for ham radio repeaters is a must in most locations in the U.S. Even yours!
There is an established group of ham radio
operators across the U.S. that keep extensive records of repeaters,
repeater input, output and control frequencies, including those not
published in directories, or on the internet repeater data bases. This
group of repeater frequency coordinators are volunteers and are "charged"
with and recommend frequencies for a proposed repeater in order
to minimize interference with other repeaters and simplex operations
across your state.
The link below will take you to the listing of groups or individuals for the United States who are active in Frequency Coordination and are acknowledged as the sole Frequency Coordinator in their respective jurisdictions. This list may not be all inclusive but are believed to be very active in frequency coordination...
Here is a state list of U.S. frequency coordinators from the NFCC. Just select your particular state or U.S territory.
After you see your state frequency coordinator section, it is advisable to research the various forms that they may require you to download and complete about your repeater, it's owner, exact location, height, etc. This is a good chance to reveiw exactly what the coordinators require of you so you can have all of the information in advance before you fill out the form and send it back to them. Some repeater frequency coordinators have a website where you can find more info. Others may only have a contact person's email address.
Below are charts listing the frequencies of the inputs and outputs recommended by the ARRL for the most popular repeater bands starting with the 6 meter band. For higher frequency bands, see the ARRL link below.
Use them wisely with the recommendations of the repeater coordinators to help reduce repeater interference and congestion....73
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