Filter
Top Products
March 1999
Part No. 001-2009-600
MAIN AUDIO CARD SCHMEATIC (2 OF 3)
FIGURE 10-37
10-32
VOTER AUDIO 25
C100
470pF
+
C235
1
R249
36k
R233
100k
+
U120A
2904
R248
120k
U115A
VOTER AUDIO
MUTE
32
1
U108-19 (1)
RX WB AUDIO 27
C103
.1
P100
R101
29.4k
R247
54.9k
C101
.0022
R281
1M
C102
.001
+
U121A
2904
2
3
1
2
3
1
R102
147k
+
U121B
2904
R103
69.8k
C104
100pF
C236
.001
C281
820pF
+
U122A
2904
7
6
5
R452
43k
R237
100k
2
3
1
C239
68pF
5253
390k
R104
15k
C105
.033
+
U121B
2904
7
6
5
C294
.1
R294
1k
R293
6.2k
+9V
+1.25
V
SOURCE
C279
.22
C237
.033
C106
.068
R106
1.07M
R105 100
+
U122B
2904
7
6
5
C276
.0022
C277
.0047
C107
.022
C238
.047
R108 110
C108
.1
R107
1.07M
+
U122C
2904
8
9
10
C109
.1
C239
.068
R110
110
R109
1.07M
+
U122D
2904
14
13
12
C278
.0068
C110
.022
C111
47k
C280
.022
R111
18.2k
+
U163A
3303
2
3
1
R112
47k
C112
.01
U113B
NORMAL
RX GATE
67
8
NORMAL RX
U157-15 (1)
U113D
RX SQUELCH
ACTIVE
GATE
1
5
16
14
R284
10k
RX SQ ACT
U157-18 (1)
R214
3.9k
R215
1k
+5V
CR107
4.3V
R216
10k
U113C
RX MUTE
GATE
11 10
9
U108-17 (1)
OPT
WO101
WO102
A301
COMPANDING
OPTION
1
EXP IN
EXP OUT
2
+5V
C249
.1
5
4
COMP IN
COMP OUT WO 103 (3)
WO 100 (3)
U114C
U114B
U114A
RX OPTION
GATE
32
1
R299
10k
+5V
8
67
RX OPTION
U108-16 (1)
U116B
RX AUDIO
GATE
67
8
U108-14 (1)
RX AUDIO
U115B
RX VOICE
GATE
67
8
U108-15 (1)
RX VOICE
R257
36k
R238
100k
+
U120B
2904
R256
36k
6
5
7
C292
360pF
U115C
RX VOICE
TO
BACKPLANE
10 11
9
U108-13 (1)
RX VOICE
TO BACKPLANE
+
C305
10
CR117
15V
CR118
15V
31 RX VOICE
U115D
RX NET
GATE
15 14
16
U155-18 (1)
RX NET
+
U165B
2904
6
5
7
R300
36k
R238
100k
R302
36k
R259
10k
R239
100k
+
U166A
MC33178
R258
2.2k
2
3
1
C290
300pF
MAIN AUDIO AMPLIFIER
13 RXA +
+
C243
10
R180
300
+
U166B
MC33178
6
5
7
R177
10k
C289
300pF
R178
100k
+
C244
10
R179
300
U116A
FSK TO
AUDIO
GATE
23
1
U108-12 (1)
FSK TO AUDIO
R263
10k
R241
100k
+
U131A
3303
R262
2.2k
2
3
1
C288
300pF
+
U165A
2904
2
3
1
R260
36k
R240
100k
R261
300k
U117A-3 (1)
TX INTERCOM
GATE
SECONDARY AUDIO
AMPLIFIER
FSK AMPLIFIER
+
C247
1
2 RXS-
+
C246
10
R184
300
+
U131B
3303
6
5
7
R181
10k
C287 300pF
R182 100k
+
C245
10
R183
300
U162C
14 3
1 RXS+
S100
10
9
11
12 5
6
8
7
+5V
SECONDARY
AUDIO TO RNT
14 RXA-
P100
VOICE AMPLIFIER
U114D
LOCAL AUDIO
MUTE GATE
14 15
16
U108-18 (1)
LOCAL AUDIO
MUTE GATE
R254
47k
R236
10k
C299
.01
+
C295
220
ON/OFF/
VOL
R291
1k
+
C286
10
+
C251
15
C254
.1
5
1
R292
39
C291
.1
3
2
4
U132
TDA2003
R290
1
C283
.1
+
C285
470
R288
220
+
C284
220
R289
2.2
R232
100
R287
100
J104
J101
EXTERNAL
SPEAKER
SPKR/MIC
LOCAL AUDIO
OUTPUT
LOCAL AUDIO
AMPLIFIER
C113
100pF
+
U135A
MC33178
1
R114
18k
C114
100pF
R113
150k
C115
100pF
HIGH-PASS FILTER > 30 kHz
C116
.001
R277
5.1k
R234
100k
+
U135B
MC33178
R115
47k
6
5
7
R116
1.5k
C117
.01
+
U123A
3303
2
3
1
R117
6.2k
R118
12k
RT100
10k
C118
.01
CR101
R119
47k
R120
10k
C120
.1
R122
10k
-5V
+
U123B
3303
6
5
7
R121 47k
+
U123C
3303
9
10
8
C119
.1
R124
1M
R123
330k
R230
7.5k
CR100
R231
10k
U159B-6 (3)
LOGIC SQUELCH
R229
1K
R228
5.1k
+5V
R125
100k
SCHMITT
TRIGGER
NOISE
RECTIFIER
NOISE AMPLIFIER
+
C240
1
-5V
R126
100k
+
U123D
3303
12
13
14
R127
470k
R128
100k
C122
.022
R129
47k
2
3
+
U135A
MC33178
1
2
3
R206
10k
R205
7.5k
-5V +9V
C121
.01
R130
100k
R131
56k
R132
56k
C123
.047
C124
.0068
+
U124B
2904
7
6
5
R251
51k
R235
100k
+
U125A
3303
R250
150k
2
3
1
RECEIVE DATA FILTER
DATA AMPLIFIER
TP DCR
+
U125B
3303
+
U125C
3303
CR108
7
5
6
CR110
CR109
7
10
9
U159C-10 (3)
DATA TO A-D GATE
R134
100k
R133
100k
-5V
+
C242
15
+
C241
15
-5V
+
U125D
3303
14
12
13
R135
47k
R136
10k
R276
18k
CR106
R212
1k
R213
5.1k
+5V
RX DATA
U111-8 (1)
C230
.01
+
C255
47
-5V
+
C207
1
+
C267
47
+
C268
47
C186
.01
C187
.01
C188
.01
C189
.01
C190
.01
C191
.01
C192
.01
C193
.01
C194
.01
C195
.01
C196
.01
C197
.01
C198
.01
C199
.01
C200
.01
C201
.01
C202
.01
C203
.01
C204
.01
C205
.01
C206
.01
C264
.01
C265
.01
C266
.01
C208
.01
C209
.01
C210
.01
C211
.01
C212
.01
C213
.01
C214
.01
C215
.01
C216
.01
C217
.01
C218
.01
C229
.01
23 RNT TX DATA
22 RNT RX DATA
P101
S101
U162C
15 2
116
RS-232 DATA
TO/FROM RNT
19
TXS+ TO S100-2 (3)
U110
MX614TN
7
8
U153D-14 (3)
RXD
RXIN
RXAMPOUT
VBIAS
GND
13
12
17
TXD
Y100
2.4576MHz
C166
15pF
C155
15pF
2
XTAL/CLK
XTAL
1
14
6
24
RXEQ
M1
Vcc
R197
1M
C306
.1
+5V
C307
100pF
R222
100k
R199
100k
C156
.1
U153C-7 (3)
18
72
U109
MX614TN
12
GND
R203
10k
R200
2.2k
+5V
17
TXD
6
M1
2
XTAL/CLK
7
RXIN
5
M0
11
TXOUT
14
5
24
RXEQ
M0
Vcc
R198
10k
+
C158
10
+5V
C159
.1
13
VBIAS
18
CLK
18
CLK