Technical Guidelines

Sub-audible Tone Access Required

***In August 2006, in an open meeting of the Repeater Council, it was decided that new coordinations on or after 01/01/2007 will be required to have tone controlled access. It is recommended that existing repeaters institute tone controlled access on or before that date. See the Regional Sub-audible Tone Plan for details.***

This decision was based on directions provided by the FCC in addressing interference issues.  The common, affordable CTCSS/DCS features of user and infrastructure equipment should minimize impacts.   Tone access is considered a common practice and helps reduce co-channel issues when propagation enhancements occur.

Standards (for 5 kHz deviation FM)

Audio Deviation:
Overall deviation: 4.5 kHz Maximum (Including PL Tone)
CTCSS deviation: 400 Hz minumum, 750 Hz maximum
DTMF deviation: 3 kHz +/- 1 kHz

Suggested ID Tone Frequency:
1020 Hz (same as FAA ID tones)
(NOAA/NWS Standard Alert Tone Frequency: 1050 Hz)

References

Standard Tone Burst Frequencies

1800 Hz 1950 Hz 2100 Hz 2250 Hz 2400 Hz
1900 Hz   2000 Hz   2200 Hz 2300 Hz

Standard DTMF Frequencies

Low Group: High Group
697 Hz    1209 Hz
770 Hz   1336 Hz
852 Hz   1477 Hz
941 Hz   1633 Hz
Deviation: 3kHz, +/- 1 kHz

Standard Continuous Tone-Coded Subaudible Squelch Frequencies

Freq. (Hz), EIA CODE Freq. (Hz), EIA CODE Freq. (Hz), EIA CODE Freq. (Hz), EIA CODE
67.0, XZ 91.5, ZZ 118.8, 2B 156.7, 5A
71.9, XA 94.8, ZA 123.0, 3Z 162.2, 5B
74.4, WA 97.4, ZB 127.3, 3A 167.9, 6Z
77.0, XB 100.0, 1Z 131.8, 3B 173.8, 6A
79.7, SP 103.5, 1A 136.5, 4Z 179.9, 6B
82.5, YZ 107.2, 1B 141.3, 4A 186.2, 7Z
85.4, YA 110.9, 2Z 146.2, 4B 192.8, 7A
88.5, YB 114.8, 2A 151.4, 5Z 203.5, M1
Deviation: 300 Hz minimum, 750 Hz maximum
Bandwidth: +/- 2%; -30 to +60 degrees C, +25 C reference
(The above tones are supported by the Communications Specialists programmable encoder/decoders.)