Ham Radio Repeater Frequency Coordination
Learn one of the most important steps to putting a new repeater on the air!
By N4UJW

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.

Therefore, anyone considering the installation of a ham radio repeater should check with the local frequency coordinator for their area prior to such installation.

They will need lots of information from you as the repeater control operator in order to "OK" your proposed frequency/s, antenna height, erp and lots more. Be prepared to have several proposed frequencies in case they do not OK your first choice. Don't be dissapointed if you don't get your desired repeater frequency in highly congested repeater areas.

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

ARRL Band Plans for the popular 6m, 2m and 440 bands
(See the ARRL for additional Band Plans for HF and higher frequency ham bands)
Red text indicates repeater frequencies in charts below.

6 Meter Band Plan ( ARRL )

(50-54 MHz): 50.0-50.1 CW, beacons 50.060-50.080 beacon subband 50.1-50.3 SSB, CW 50.10-50.125 DX window 50.125 SSB calling 50.3-50.6 All modes 50.6-50.8 Nonvoice communications 50.62 Digital (packet) calling 50.8-51.0 Radio remote control (20-kHz channels) 51.0-51.1 Pacific DX window 51.12-51.48 Repeater inputs (19 channels) 51.12-51.18 Digital repeater inputs 51.62-51.98 Repeater outputs (19 channels) 51.62-51.68 Digital repeater outputs 52.0-52.48 Repeater inputs (except as noted; 23 channels) 52.02, 52.04 FM simplex 52.2 TEST PAIR (input) 52.5-52.98 Repeater output (except as noted; 23 channels) 52.525 Primary FM simplex 52.54 Secondary FM simplex 52.7 TEST PAIR (output) 53.0-53.48 Repeater inputs (except as noted; 19 channels) 53.0 Remote base FM simplex 53.02 Simplex 53.1, 53.2, 53.3, 53.4 Radio remote control 53.5-53.98 Repeater outputs (except as noted; 19 channels) 53.5, 53.6, 53.7, 53.8 Radio remote control 53.52, 53.9 Simplex

2 Meter Band Plan (ARRL)

144.00-144.05 EME (CW) 144.05-144.10 General CW and weak signals 144.10-144.20 EME and weak-signal SSB 144.200 National calling frequency 144.200-144.275 General SSB operation 144.275-144.300 Propagation beacons 144.30-144.50 New OSCAR subband 144.50-144.60 Linear translator inputs 144.60-144.90 FM repeater inputs 144.90-145.10 Weak signal and FM simplex (145.01,03,05,07,09 are widely used for packet) 145.10-145.20 Linear translator outputs 145.20-145.50 FM repeater outputs 145.50-145.80 Miscellaneous and experimental modes 145.80-146.00 OSCAR subband 146.01-146.37 Repeater inputs 146.40-146.58 Simplex 146.52 National Simplex Calling Frequency 146.61-146.97 Repeater outputs 147.00-147.39 Repeater outputs 147.42-147.57 Simplex 147.60-147.99 Repeater inputs Notes: The frequency 146.40 MHz is used in some areas as a repeater input. This band plan has been proposed by the ARRL VHF-UHF Advisory Committee.

420 - 450 MHz - 70 Centimeters (ARRL)

420.00-426.00 ATV repeater or simplex with 421.25 MHz video carrier control links and experimental 426.00-432.00 ATV simplex with 427.250-MHz video carrier frequency 432.00-432.07 EME (Earth-Moon-Earth) 432.07-432.10 Weak-signal CW 432.10 70-cm calling frequency 432.10-432.30 Mixed-mode and weak-signal work 432.30-432.40 Propagation beacons 432.40-433.00 Mixed-mode and weak-signal work 433.00-435.00 Auxiliary/repeater links 435.00-438.00 Satellite only (internationally) 438.00-444.00 ATV repeater input with 439.250-MHz video carrier frequency and repeater links 442.00-445.00 Repeater inputs and outputs (local option) 445.00-447.00 Shared by auxiliary and control links, repeaters and simplex (local option) 446.00 National simplex frequency 447.00-450.00 Repeater inputs and outputs (local option)

 Scan Police, Fire, Rescue, Ham Radio, Aircraft, Marine, and much more!

Amateur Radio Transceivers on Amazon.com!