The ARRL National Repeater Directory publishes what is called "ARRL National Band Plans." As is mentioned, these plans are set forth as a starting guideline for repeater users. Each coordinator across the nation has an option of either following the ARRL Band Plan, or adding, changing, or deleting certain frequencies or portions to better utilize spectrum in their particular coordination location. One should never assume the ARRL suggested band plan is correct for all areas.
Of particular note, some simplex frequencies listed in the ARRL Band Plan may, or may not, be repeater inputs in some areas as our coordinators make changes to better suit their area.
Another example is the different assignments of spectrum for FM Voice Simplex, and Packet/ Digital Simplex. Repeater users as well as packet/digital users are asked to honor these frequencies by utilizing the ones specifically assigned to the particular mode they are operating.
All coordination and spectrum management by coordinators is based on "gentlemen's agreements" and usage by all hams whether they are operators using FM repeaters, simplex, or packet digital using duplex packet modes or simplex. For spectrum management to continue to work successfully around the nation, operators must take the responsibility of working only frequencies in the mode in which that frequency is assigned.
This prevents chaos and interference and arguments. All modes of amateur operations are well represented by frequency spectrum assignments on most all bands. Using only those frequencies assigned prevents unwanted problems.
1. 29 MHz
2. 50-54 MHz
3. 144 - 148 MHz
4. 222-225 MHz
5. 420-450 MHz
6. 902-928 MHz
7. 1240-1300 GHz