Every county in the Iowa Section has one or more simplex frequencies assigned for emergency planning. This plan helps prevent interference between adjacent counties. Please note that any operation is permitted to use any available frequency, as needs dictate — the planning represents a starting point.
Please direct questions to N0GUD, EC for District 6.
| District 1 Mutual Aid | 146.400 |
| District 2 Mutual Aid | 147.405 |
| District 3 Mutual Aid | 147.585 |
| District 4 Mutual Aid | 146.595 |
| District 5 Mutual Aid | 147.405 |
| District 6 Mutual Aid | 147.585 |
| ADAIR | 146.460 |
| ADAMS | 147.540 |
| ALLAMAKEE | 147.435 |
| APPANOOSE | 146.430 |
| AUDUBON | 147.555 |
| BENTON | 146.400 |
| BLACKHAWK | 147.450 |
| BOONE | 146.550 |
| BREMER | 147.555 |
| BUCHANAN | 146.580 |
| BUENAVISTA | 147.435 |
| BUTLER | 146.475 |
| CALHOUN | 147.570 |
| CARROLL | 147.540 |
| CASS | 147.480 |
| CEDAR | 147.450 |
| CERROGORDO | 147.570 |
| CHEROKEE | 146.490 |
| CHICKASAW | 147.570 |
| CLARKE | 147.540 |
| CLAY | 146.475 |
| CLAYTON | 146.550 |
| CLINTON | 146.460 |
| CRAWFORD | 146.475 |
| DALLAS | 147.480 |
| DAVIS | 146.535 |
| DECATUR | 146.490 |
| DELAWARE | 147.465 |
| DESMOINES | 147.435 |
| DICKINSON | 146.460 |
| DUBUQUE | 146.475 |
| EMMET | 147.555 |
| FAYETTE | 147.510 |
| FLOYD | 146.490 |
| FRANKLIN | 146.565 |
| FREMONT | 147.465 |
| GREENE | 147.525 |
| GRUNDY | 147.480 |
| GUTHRIE | 146.445 |
| HAMILTON | 147.510 |
| HANCOCK | 146.580 |
| HARDIN | 147.450 |
| HARRISON | 147.435 |
| HENRY | 146.550 |
| HOWARD | 146.565 |
| HUMBOLDT | 147.525 |
| IDA | 146.445 |
| IOWA | 147.525 |
| JACKSON | 146.430 |
| JASPER | 147.555 |
| JEFFERSON | 146.535 |
| JOHNSON | 147.495 |
| JONES | 147.555 |
| KEOKUK | 147.540 |
| KOSSUTH | 146.415 |
| LEE | 147.540 |
| LINN | 146.505 |
| LINN2 | 147.480 |
| LOUISA | 147.450 |
| LUCAS | 146.445 |
| LYON | 147.480 |
| MADISON | 147.495 |
| MAHASKA | 146.415 |
| MARION | 147.510 |
| MARSHALL | 146.505 |
| MILLS | 147.435 |
| MITCHELL | 147.510 |
| MONONA | 146.565 |
| MONROE | 147.450 |
| MONTGOMERY | 147.525 |
| MUSCATINE | 146.445 |
| OBRIEN | 147.570 |
| OSCEOLA | 147.510 |
| PAGE | 146.460 |
| PALOALTO | 146.535 |
| PLYMOUTH | 146.415 |
| POCAHONTAS | 146.490 |
| POLK | 146.490 |
| POLK2 | 146.430 |
| POLK3 | 147.420 |
| POLK4 | 146.460 |
| POTTAWATTAMIE | 146.430 |
| POWESHIEK | 146.460 |
| RINGGOLD | 146.460 |
| SAC | 147.555 |
| SCOTT | 146.475 |
| SHELBY | 146.565 |
| SIOUX | 147.555 |
| STORY | 146.430 |
| TAMA | 146.580 |
| TAYLOR | 147.480 |
| UNION | 147.435 |
| VANBUREN | 146.490 |
| WAPELLO | 147.555 |
| WARREN | 146.565 |
| WASHINGTON | 146.415 |
| WAYNE | 146.505 |
| WEBSTER | 147.435 |
| WINNEBAGO | 147.510 |
| WINNESHIEK | 146.460 |
| WOODBURY | 146.535 |
| WORTH | 146.415 |
| WRIGHT | 146.475 |