United States Forest Service

USFS repeaters commonly repeat the CTCSS tone that was used on the input for whichever mountain was used. It's recommended that all frequencies be entered in CSQ mode. In some cases where direct mode is used on the repeater output frequency, the tone may be 103.5Hz.

Paired with the 16 standardized tones are the P25 digital Network Access Code (NAC) that corresponds with each standard tone for natural resource agencies, state and federal, for California.  The first 8 are a nationwide standard for the Forest Service, used by most of the NPS and some BLM state/district offices.

16 Common tones with corresponding NAC now in use:                

        CTCSS    NAC
1     110.9       455
2     123.0       4CE
3     131.8       526
4     136.5       555
5     146.2       5B6
6     156.7       61F
7     167.9       68F
8     103.5       40B
9     100.0      3E8
10   107.2      430
11   114.8      47C
12   127.3      4F9
13   141.3      585
14   151.4      5EA
15   162.2      656
16   192.8      788