Codan Radio P25 Training Guide - Manual (Page 34)

TRAINING GUIDE | P25 RADIO SYSTEMS
Chapter 3: P25 Technical Information Page 26
CTCSS to NAC Conversion
Early TIA documents specifi ed a formula for converting analog CTCSS tones and DCS codes to specifi c
NAC codes. Those documents have since been removed and the selection of NAC codes has been
left to the user. Some government agencies have defi ned a conversion table for their own use for
translating CTCSS to NAC codes (eg. State of California and others).
Shown below is the early TIA conversion table from CTCSS to NAC codes. These codes were
determined by taking the CTCSS frequency and multiplying it by ten, then converting the integer result
to a hexadecimal number.
CTCSS to NAC code conversion chart
CTCSS NAC CTCSS NAC
67.0 Hz $29E 136.5 Hz $555
69.3 Hz $2B5 141.3 Hz $585
71.9 Hz $2CF 146.2 Hz $5B6
74.4 Hz $2E8 151.4 Hz $5EA
77.0 Hz $302 156.7 Hz $61F
79.7 Hz $31D 162.2 Hz $656
82.5 Hz $339 167.9 Hz $68F
85.4 Hz $356 173.8 Hz $6CA
88.5 Hz $375 179.9 Hz $707
91.5 Hz $393 186.2 Hz $746
94.8 Hz $3B4 192.8 Hz $788
97.4 Hz $3CE 203.5 Hz $7F3
100.0 Hz $3E8 206.5 Hz $811
103.5 Hz $40B 210.7 Hz $83B
107.2 Hz $430 218.1 Hz $885
110.9 Hz $455 225.7 Hz $8D1
114.8 Hz $47C 229.1 Hz $8F3
118.8 Hz $4A4 233.6 Hz $920
123.0 Hz $4CE 241.8 Hz $972
127.3 Hz $4F9 250.3 Hz $9C7
131.8 Hz $526