Service manual

3-61
March 2000
Part No. 001-3139-502
RDM INTERFACE BOARD SCHEMATIC (3 OF 3)
FIGURE 3-50
FOLDOUT
+
U208A
2904
2
3
1
R243
10k
R244
7.5k
+9V-5V
R242
47k
R240
100k
C234
.022
C235
.01
R241
100k
R245
56k
C236
.047
R246
56k
+
U208B
2904
7
6
5
C237
.0068
R247
51k
R248
100k
+
U210A
3403
1
2
3
R249
270k
+
U210C
3403
8
9
10
CR206
CR207
+
U210B
3403
7
6
5
CR205
R251
47k
-5V
+
C238
15
-5V
+
C239
15
R250
100k
R158
100k
+
U210D
3403
C240
.001
12
13
14
R253
10k
COMPARATOR
DC RESTORATION
DATA AMPLIFIER
RECEIVE DATA FILTER
CR208
R255
5.1k
+5V
R256
1k
R254
18k
10
9
11
U217C
DATA TO A-D
U114-13 (1)
23
1
U115-13 (1)
U217A
FSK TO AUDIO GATE
+
U205A
33178
2
3
1
R221
5.1k
C225
100pF
R220
150k
C224
100pF
C226
100pF
R219
18k
C227
.001
R222
100k
+
U205B
33178
4
6
5
R223
47k
NOISE AMPLIFIER
SQ ADJ
HIGH-PASS FILTER > 30 kHz
C228
20pF
R224
1.5k
C229
.01
+
U207A
3403
1
2
3
R225
6.2k
R226
12k
RT201
10k
C230
.01
CR201
CR202
R228
10k
R229
47k
C231
.1
-5V
R227
10k
+
U207B
3403
7
6
5
R230
47k
C232
.1
+
U207C
3403
8
9
10
R232
1M
R231
330k
R233
1M
CR204
R258
2.4k
+5V
R259
1k
R257
10k
R234
100k
+
C233
1
-5V
R235
100k
+
U207D
3403
14
12
13
R236
470k
R237
10k
CR203
4.3V
R238
3.9k
R239
1k
+5V
14
15
16
U115-17 (1)
RX SQ ACT
U211D
RX SQ
ACTIVE GATE
R218
10k
U115-18 (1)
NORMAL RX
TIMING BUFFER
SCHMITT TRIGGER
NOISE RECTIFIER
+
U201A
2904
RX WB AUDIO 9
J201
C201
.1
R201
29.4k
C202
.0022
R202
54.9k
R203
1M
C203
.001
3
2
1
R204
147k
R205
69.8k
C206
100pF
+
U201B
2904
5
6
7
C205
.001
C204
820pF
R206
43k
R207
100k
NARROW BAND
AUDIO ADJ
+
U203A
2904
3
2
1
R208
390k
C207
68pF
C301
.1
+
U204B
33178
5
6
7
+1.25V
R292
6.2k
R293
1k
+9V
R209
15k
C208
.033
C209
.22
C210
.033
R210
100
C211
.068
R211
1.07M
+
U203B
3403
5
6
7
C213
.0022
C212
.022
C214
.0047
C215
.047
R212
110
C216
.1
R213
1.07M
+
U203C
3403
10
9
8
C218
.0068
C217
.022
R215
1.07M
C221
.022
C222
.022
C219
.068
R214
110
C220
.1
R216
18.2k
+
U203D
3403
12
13
14
+
U204A
33178
3
2
1
R217
47k
C223
.01
DE-EMPHASIS
HIGH-PASS FILTER > 300 Hz
LOW -PASS FILTER < 3 kHz
7
89
10611
U211B
NORMAL
RX GATE
U211C
RECEIVE
MUTE GATE
U115-16 (1)
RX OPTION
R260
10k
+5V
U212C
9
10 11
1
2
7
6
8
3
U211A
RECEIVE
OPTION GATE
U212B
WO 201
WO202
OPTION
14 15
16
U212D
LOCAL AUDIO
MUTE GATE
U115-16 (1)
R261
47k
R262
10k
R263
1k
+
C242
10
1
5
LOCAL AUDIO
ON/OFF/VOL
+15V
+
C241
220
+
C245
15
C246
.1
R264
39
C244
.1
C243
.01
+
C249
470
4
2
+
C248
470
R267
220
R266
2.2
R265
1
C247
.1
R268
51
J204
EXT SPKR
LOCAL AUDIO
OUTPUT
U213
TDA2003
7 RDM AUDIO
J106
U115-19 (1)
RX MUTE
TP
J210
2
3
1
U212A
RECEIVE
AUDIO GATE
U115-14 (1)
RX AUDIO GATE
R270
10k
R271
100k
+
U215A
33178
1
2
3
R272
36k
C250
360pF
R273
1k
+
U215B
33178
7
6
5
C251
300pF
R276
300
R274
100k
+
C253
10
R275
300
+
C252
10
3
4
2
1
T201
600
1 2
J205
+
C304
10
1 2
J206
+
C305
10
RV201
RV202 RV203
FSK AUDIO -
FSK AUDIO +
R281
36k
R282
100k
+
U216A
2904
1
2
3
R283
36k
+
C254
1
U218
7911
23
24
TC
MC1
MC4
RING
BRTS
Vcc
MC0
MC2
XTAL 1
XTAL 2
C258
10pF
Y201
2.4576 MHz
C257
10pF
19
17
2
11
1
21
18
8
+15V
R197
910
C155
.0022
6
7
CAP 1
CAP 2
R280
100k
5
9
22
12
RC
AGND
DGND
RTS
C259
.047
R279
1M
+
C259
10
R277
10k
3
16
RESET
DTR
U114-12 (1)
U217B
LOGIC SQ A-D
76
8
A-D LEVEL
J202
A-D LEVEL
J203
TP
J211
J212
TP
J207
J208
U125-8 (1)
RX DATA
TP
J209
RX WBAND 9
J201
RSSI 7
HS LK RX 19
SYN LK RX 14
RXINJ 13
R284
10k
R285
43k
U219A
14050
32
R286
10k
U219B
14050
54
R287
43k
R288
10k
U220
HEF405TBTD
1
13
14
15
12
Y4
Y0
Y1
Y2
Y3
R289
22k
R290
22k
R291
22k
9
10
11
6
3
A2
A1
A0
E
Z
U116-17 (1)
U116-18 (1)
U116-19 (1)
U117-18 (1)
U105-71 (1)