MARC Standards



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  1. Coordination Standards.
    1. Coverage radius and protection radius figures for the coordination classes are as follows:

Class of Repeater

Coverage Radius

Protection Radius


15 miles


Local (not available see C below)

15 miles

25 miles


25 miles

40 miles


40 miles

55 miles


55 miles

70 miles

      1. In all cases, regardless of power output or ERP, the repeater's transmitter is to be configured so that the transmitter's physical coverage radius does not exceed the repeater's coordinated coverage radius.

2.     Remote receivers shall be configured so that their coverage area lies within the coordinated coverage area of the repeater.

3.     Exceeding the coverage radius limits can be cause for revocation of the station's coordination.

4.     All new coordinations will include a 25 mile separation from adjacent channel coordinations.

5.     All new coordinations, except SNPR class, will be greater than 120 miles from any existing coordinated co-channel repeaters, (This is reciprocal for any new out-of-state repeaters per Great Lakes Council meeting September 1989), however, the Coordinator, for the 440 Band, may Coordinate Repeaters at a distance separation of 100 miles.

To better serve the amateur community and to better utilize our amateur spectrum. As of April 2, 1996 all new repeater coordinations must cover a min coverage of 10 miles radius. Existing repeaters must have a minimum coverage of 10 miles radius by April 2, 1997 excluding snappers. If a repeater system cannot accrue a minimum coverage the council will re-evaluate the system for re-allocation.

6.     The Coordinator will use the location of transmitter, antenna elevation, beam direction, ERP, polarization, terrain and adjacent channel use to determine the distance between One Way Link transmitters. Repeater type spacing is not required.

7.     The Coordinator will use the protected radius of the repeater to determine Control cochannel assignments. (minimum 25 Miles) Example: Regional 55 mile protection and District 40 Miles - distance between assignments is 95 Miles. Two SNPR Controls would be 50 Miles. Adjacent channel will not be considered unless interference is encountered. Repeater type spacing is not required. Repeaters with more than one site (transmitter and links) should use one control frequency for their complete system if possible.

8.     The coordinator may grant reasonable variations in distance separations with the use of Documented Waivers from all parties and a corresponding condition statement in the Coordination Documents in case interference is experienced.

9.     Auxiliary stations that are used to link two or more individual repeater systems shall comply with the following:  Transmitter power may exceed 10 watts to accomplish the link but shall not execeed 50 watts. Links using transmitter power levels in excess of 10 watts shall use directional antennas with a minimum of 9 dBi forward gain and the antennas must be aimed so that the major lobe is centered on the receive site.  Higher gain antennas and using the minimum power necessary to complete a link is recommended as it allows the coordinator to more effectively assign the available spectrum.  These links are not intended to extend the coverage of any individual repeater beyond its coordinated area.

10. Allow One Way Links to be coordinated North and East of the "A" line in the 430.525 to 430.975 frequency range.  Links will be limited to the area East of 84 degrees longitude. See resolution #10.

11.  Adjacent channel spacing mileage requirements for across state lines coordination's. (Analog Only) see resolutions #12 and #13

                                                                      a.           5 kHz - 100 miles

                                                                      b.           10 kHz - 70 miles

                                                                      c.           15 kHz - 25 miles

                                                                      d.           20 kHz - 25 miles 

Note: Co-channel spacing is 100 miles

12. Allow the use of the 441/446 band segments for repeaters in other states providing the following requirements are met: (see resolution #13)

                                                                      a.           HAAT <= 70'

                                                                      b.           ERP <= 100 watts

                                                                      c.           Co-channel separation >= 80 miles                                                                                     

Note: Do not use the following reserved frequencies: 441.050, 441.075, 446.000, 446.025 446.050, 446.075, 446.100, 446.125, and 446.150 which are reserved for packet and simplex operations.

13. MARC will coordinate digital repeaters with a necessary bandwidth of less than 6.25 kHz on splinter channels on the 2 meter and 70 CM bands. MARC will coordinate digital repeaters with a necessary bandwidth of less than 9 kHz on splinter channels in the 70 CM band. Necessary bandwidth based on FCC emission designator. [ splinter means 1/2 way between regular channels].

Repeater separation standards will be a minimum of 70 miles between co-channel repeaters. Adjacent channel spacing between digital repeaters will be left to coordinators discretion; however spacing to adjacent channel analog repeaters will be no less than 50 miles. (see resolution #11)

14. Add the pair 441.075 repeater input / 446.075 repeater output and 441.150 repeater input / 446.150 repeater output to the available repeater pairs for coordination by MARC.  These pairs would not be coordinated in Grand Rapids because of an existing ATV coordination. See Resolution #15.


                          B.           Shared Non-Protected Repeater (SNPR) coordination class.

      1. Maximum ERP permitted shall be 15 watts.

2.     CTCSS access is required and the specific tone shall be assigned by the appropriate coordinator.

3.     Frequency pairs are as follows:

        1. 144 MHz band: 147.50 input / 146.50 output (1 pair)
        2. 222 MHz band: 222.38 input / 223.98 output (1 pair)
        3. 440 MHz band: 440.50 input / 445.50 output (1st pair)
        4. 440 MHz band: 441.50 input / 446.50 output ( 2nd pair) see resolution #14
        5. 440 MHZ band: 447.125 input / 442.125 output (3rd pair) see resolution #19

4.     Any attempt to evolve to a larger coverage radius will result in de-coordination of the repeater.

5.     Trustees and sponsors agree to accept co-channel and adjacent channel interference from other repeaters provided that those other repeaters are being operated in accordance with their coordination parameters.

6.     Where interference is being caused to any non-SNPR system, it shall be the responsibility of the SNPR trustee to work with the appropriate coordinator to resolve the problem.

7.     Although no out-of-state communication is required to coordinate a SNPR, care must be taken to avoid creating an interference problem with existing out-of-state operations.

                          C.           No new coordinations will be allowed in the Local coordination class.

                          D.           Quadrant coordination class.

      1. To receive Quadrant status, the trustee must document the potential to achieve the requested coverage radius through submission of Height Above Average Terrain calculations, detailed descriptions of future station equipment, a system map, evidence of detailed terrain analysis, and end-user need, as approved by the membership.

2.     To maintain Quadrant status, the applicant must document that coverage of the coordinated coverage radius does in fact exist. This will be accomplished with annual submission of an operational report, a coverage radius map, an updated system diagram, and evidence of user need, as approved by the membership.

                          E.           The standard for testing the repeater's coverage radius shall be a mobile station with a center roof-mounted antenna with an ERP of 25 watts. This can be a 25 watt radio with a quarter-wave antenna or a 15 watt radio with a 5/8 wave antenna. Using this equipment, a mobile station is inside a repeater receiver's coverage radius if the system is receiving the mobile station at least an 80% copy 100% of the time. Inversely, for testing repeater transmitters, a mobile station using a 5/8 wave antenna is inside a repeater transmitter coverage radius if the mobile station is receiving the repeater's transmitter at least an 80% copy 100% of the time. All tests should be made at average terrain during non-enhanced band conditions.

                          F.           Any coordinated repeater operating within its coordination parameters at the time of adoption of these standards shall be grandfathered at those parameters.

1.     If updates by submitting a Technical Data Sheet (from the system sponsor) are not received a minimum of once every two years the (MARC) coordinator may withdraw the Co-ordination Authorization.

2.     When a determination has been made, by means of research (to be documented by the Frequency Coordinator) that a frequency pair has not been in use for sixty days, the Frequency Coordinator will send an inquiry by certified mail, return receipt requested, to the trustee and sponsor of record. Should no response be received within thirty days from the date of receipt of this letter, or if the letter be returned as not deliverable, the coordination of the frequency pair will be rescinded. If the trustee responds within thirty days, in writing to the coordinator and the chairman of M.A.R.C., requesting that the coordination be maintained, at the discretion of the Board, any further action may be stayed for up to ninety days.

3.     If the repeater is moved more than 5 miles from the original location without notification to the M.A.R.C. coordinator and chairman, COORDINATION IS AUTOMATICALLY WITHDRAWN.

4.     In the event of the sale of a coordinated repeater, the coordination of the repeater will have a temporary status for the period of 60 days, UNTIL THE SELLER RELINQUISHES THE FREQUENCY COORDINATION IN WRITING (sent to the frequency coordinator and chairman by U.S.P.S. mail, and the buyer agrees to all of the coordination guidelines, and the unmodified coordination has been approved by the coordinator. IF THESE TERMS CANNOT BE MUTUALLY AGREED UPON BY ALL PARTIES, THE COORDINATION WILL BE CONSIDERED VOID.

5.     (Holders of frequency coordination, IE: sponsors and trustees) who terminate their coordination as a result of the sale or transfer of their system, or for other reasons with the intent not to resume such operation shall notify the Coordinator and Chairman of the termination within 30 days of the cessation of the operation and the surrender of the frequency involved. The Coordinator will then entertain requests for eligible applicants for the use of the frequency, IN THE BEST INTERESTS OF AMATEUR RADIO AND THE PUBLIC SERVICE.


     II.           Band Plans.

A.     All band plans shall be in accordance with the ARRL recommended band plans as listed in the ARRL Repeater Directory, 1989-90 edition, except as noted below.  Non-standard pairs or offsets will not be coordinated.

B.    50 MHz Band 




50.000 - 50.100


CW, beacons


50.060 - 50.080

beacon sub-band

50.100 - 50.300





SSB calling

50.300 - 50.600


all modes

50.600 - 50.800





digital calling

50.800 - 51.000
(20 KHz channels)


remote control

51.000 - 51.100


Pacific DX window

C.    All activities above 51.100 are on 20 KHz channels 




51.120 - 51.480


repeater inputs


51.120 - 51.180

digital repeaters

51.500 - 51.600



51.620 - 51.980


repeater outputs


51.620 - 51.680

digital repeaters

52.000 - 52.480
(except as noted)


repeater inputs


52.020 - 52.040




test pair

52.500 - 52.980
(except as noted)


repeater outputs



National calling






test pair

53.000 - 53.480
(except as noted)


repeater inputs



remote base simplex






remote control



remote control



remote control



remote control

53.500 - 53.980
(except as noted)


repeater outputs



remote control






remote control



remote control



remote control




D.    144 MHz Band 

The following frequency pairs are to be utilized for repeater coordinations. All offsets will be 600 KHz, except SNPRs. The division of the band segments will be made in 20 KHz increments. 




144.510 - 144.890

145.110 - 145.490


146.020 - 146.380

146.620 - 146.980





147.600 - 147.980

147.000 - 147.380


E.     For packet operations, the following channels will be protected from coordinated operations. 

144.910, 144.930, 144.950, 144.970, 144.990


145.010, 145.030, 145.050, 145.070, 145.090


147.540, 147.560, 147.580


F.     222 MHz Band 

The following frequency pairs are to be utilized for repeater coordinations. All offsets will be 1.6 MHz. The division of the band segments will be in 20 KHz increments. 




222.340 - 222.360

223.940 - 223.960





222.400 - 223.380

224.000 - 224.980


G.    The following frequencies are to be allocated to voice links. The division of this band segment will be in 20 KHz increments. Transmitter power output is limited to 10 watts. 

223.620 - 223.920

Voice links

H.     A statewide control link frequency of 222.320 is allocated to any trustee desiring a 222 MHz control frequency. For packet operations, the following channels will be protected from coordinated operations. 

223.520, 223.540, 223.560, 223.580, 223.600


I.        420 MHz Band 

The following frequency pairs are to be utilized for repeater coordinations. All offsets will be 5 MHz. The division of the band segment will be in 25 KHz increments. 




447.000 - 449.975

442.000 - 444.975


The following frequencies are to be allocated to voice and control links. Reserved packet and simplex frequencies are also indicated. The division of these band segments will be in 25 KHz increments. Transmitter power output is limited to 10 watts for link transmitters.Please follow the link below to view the 440 Band Plan for Voice and Control links, ATV, Packet, Simplex and Repeater Frequencies.

J.      902 MHz Band  (33cm)

The purpose of this section is to place a uniform and specific written documentation concerning coordination and cooperation in the use of the 33cm spectrum as allocated to Amateur Radio by the FCC in accordance with statements made in Article I of the MARC Bylaws.

Frequencies Covered:

     902.0000 MHz to 928.0000 MHz

902.0000 – 902.2875

SSTV, FAX, ACSSB, Experimental

902.2125 – 902.9875

FM Repeater Inputs (25 MHz duplex split, 12.5 KHz spacing)

903.0000 – 903.0500

EME Exclusive

903.0700 – 903.0800

CW Beacons

903.1000 -           

CW, SSB Calling Frequency

903.4000 – 903.6000

Cross Band Linear Translator Inputs

903.6000 – 903.8000

Cross Band Linear Translator Outputs

903.8000 – 904.0000

Experimental Beacons Exclusive

904.0000 – 906.0000

Digital Communications

906.0000 – 907.0000

Narrow Band FM Simplex (25 KHz channels)

906.5000 -    

National Calling Frequency

907.0000 – 910.0000

FM Repeater Inputs 5KHz modulation (12MHz split)

910.0000 – 912.0000

Narrow-band Simplex Repeater Links

912.0000 – 916.0000


916.0000 – 918.0000

Digital Communications

918.0000 – 919.0000

Narrow Band FM Control Links/Remote Bases

919.0000 – 922.0000

FM Repeater Outputs

927.0125 – 927.9875

Auxiliary Simplex Link Frequencies

927.2125 – 927.4625

Auxiliary FM Duplex Link Input Frequency Pairs

927.4875 – 927.7250

FM Repeater Outputs (25 MHz duplex split, 12.5 KHz spacing)

927.7375 – 927.7875

FM Voice Simplex Channels  

922.0000 – 928.0000

Wideband Experimental, ATV, Simplex, Spread Spectrum





          The following is criteria to be met for the coordination of repeaters in the 33cm band.

          Repeater frequencies must fit into the bandplan as stated above.

          Repeater owner/Trustee must comply with rules concerning TDS submission as stated in the MARC



          Co-Channel Protection Distance:

          No repeater shall be given a protection distance of more than 50 miles without

          a study clearly showing the need for such. This study can be done using

          methods outlined elsewhere in this document. The protection distance of a

          coordinated repeater may be less than 50 miles, but shall not exceed 50 miles

          without a propagation study indicating the need for additional protection distance.


          Adjacent Channel Protection :

          Repeaters using adjacent channels shall have a minimum physical distance between

          transmitters. This distance shall be determined by using half of the distance of the

          Protection Radius of the repeater with the largest protection distance.




Channel. – Frequencies within a given spectrum with designated spacing to provide

                   uniformity in frequency utilization.


Co-Channel. – A common frequency shared between two coordinated repeaters.


Adjacent Channel. – A channel that falls either immediately before or after the

                                  desired operating frequency.


Protection Distance. – The minimum physical distance between two transmitters.


Protection Radius. – The averaged distance from the transmitter that the transmitted

                                  signal is useable by a receiver of reasonable sensitivity. 


Coverage Prediction Study:


Coverage prediction shall be done in one of three ways.

    1: Accept the minimum protection radius as the maximum coverage area.

    2: True coverage area study done with calibrated test equipment.

    3: Approved software designed to provide coverage modeling.


Coverage area is to be defined as an average distance of coverage from the

Repeater transmitter based on a signal of at least -110 dBm in 75% of locations

75 % of the time. This translates roughly to a signal that is useable by an average

user listening to a voice repeater in a mobile situation with a radio of average

receive capability (roughly 0.3 microvolts).



Adapted from MARC Standards, REV 01

2 December 1989, as amended


Section J 902 MHz Band(33cm) was added to MARC Standards on June 4, 2005 by voice vote, after being in use as Resolution # 3, since September 2003.