BR200D-U1/BR300D-U1
Service Manual
30
CTCSS/DCS signals from MCU are sent to TCXO for modulation respectively .
CTCSS/DCS signals from receiver are sent to MCU(pin 25) for decoding, and then MCU test if there
are CTCSS/DCS signals with the same setting of the station to decide whether open the speaker or
not.
CTCSS (continuous tone control squelch system, hereinafter referred to as CTCSS), is a kind of
squelch control system with modulation on carrier and continuous sub-audio signals as pilot tone. If
CTCSS function is set, the call is available only at the same CTCSS frequency of both receiving and
transmitting parties to avoid the disturbance of other signals.
The station has 39 groups of standard CTCSS frequency for your selection, such as Table 1.
CTCSS signals produced by MCU are sent to TCXO for modulation.
Table 1 CTCSS Frequency Table
No. Frequency
[Hz]
No. Frequency
[Hz]
No.
Frequency
[Hz]
No. Frequency
[Hz]
1 67.0 11 94.8 21 131.8 31 186.2
2 69.3 12 97.4 22 136.5 32 192.8
3 71.9 13 100.0 23 141.3 33 203.5
4 74.4 14 103.5 24 146.2 34 210.7
5 77.0 15 107.2 25 151.4 35 218.1
6 79.7 16 110.9 26 156.7 36 225.7
7 82.5 17 114.8 27 162.2 37 233.6
8 85.4 18 118.8 28 167.9 38 241.8
9 88.5 19 123.0 29 173.8 39 250.3
10 91.5 20 127.3 30 179.9
DCS signaling
：
DCS (Digital code squelch), is a kind of continuous digital code modulated on carrier with voice signal
and used for squelch control. If DCS function is set, the speaker is available only when receiving the
same DCS code to avoid the disturbance of useless signals.
The station has 83 kinds of standard codes including positive and inverse code for your selection, such
as Table 2.
DCS signals produced by MCU (PWM waveform) are sent to TCXO for modulation.
CTCSS/DCS signals from receiver are sent to MCU for decoding, and then MCU test if there are DCS
codes with the same setting of the station to decide whether open the speaker or not.
Table 2
DCS Coding Schedule
023
114
174
315
445
631
025
115
205
331
464
632
026
116
223
343
465
654
031
125
226
346
466
662
Summary of Contents for BR200D-U1
Page 1: ...BR200D U1 BR300D U1 Service Manual 1 BR200D U1 BR300D U1 Service Manual ...
Page 17: ...BR200D U1 BR300D U1 Service Manual 17 Exploded View of the Parts ...
Page 20: ...BR200D U1 BR300D U1 Service Manual 20 DR7000 2 ...
Page 36: ...BR200D U1 BR300D U1 Service Manual 36 Chapter 6 PCB Layout ...
Page 37: ...MIC1 C5 D4 D5 D8 C4 C3 R1 D2 D3 D6 C7 C8 C9 J1 D1 D9 C2 D7 C6 C13 C1 ...
Page 70: ...BR200D U1 BR300D U1 Service Manual 66 Chapter 10 Block and Schematic ...
