3-1
3. OPERATION
OVERVIEW
This section of the manual covers key ideas and features that define the operation of the
Model 38A Repeater Tone Panel.
CTCSS TONES AND DIGITAL CODED SQUELCH (DCS)
The Model 38 monitors the channel for CTCSS tones and/or DCS codes. When a tone or
code is detected, it is converted into a User-Number that contains the user privileges and
attributes. The DCS decode numbers are completely user programmable. Two versions of the
Model 38 are available; 38 CTCSS + 22 DCS users (see Table 3. -1), or 50 CTCSS + 18
DCS users (Table 3. -2).
When ordered with the 50 tone set, the unit has a narrower CTCSS decoder bandwidth than
the standard 38 tone version. The 50 tone version is not recommended for use with radios
that use tunable encoders, due to the possibility of the encoder becoming mistuned or drifting
onto adjacent tones.
Table 3. -1. User Number Cross reference Table: 38 Tone Version
User Tone User Tone User Tone User Code
1 67.0 16 114.8 31 192.8 46 DCS
2 71.9 17 118.8 32 203.5 47 DCS
3 74.4 18 123.0 33 210.7 48 DCS
4 77.0
19 127.3 34 218.1 49 DCS
5 79.7
20 131.8 35 225.7 50 DCS
6 82.5
21 136.5 36 233.6 51 DCS
7 85.4
22 141.3 37 241.8 52 DCS
8 88.5
23 146.2 38 250.3 53 DCS
9 91.5
24 151.4 39 DCS 54 DCS
10 94.8 25 156.7 40 DCS 55 DCS
11 97.4
26 162.2 41 DCS 56 DCS
12 100.0 27 167.9 42 DCS 57 DCS
13 103.5 28 173.8 43 DCS 58 DCS
14 107.2 29 179.9 44 DCS 59 DCS
15 110.9 30 186.2 45 DCS 60 DCS