Service manual

2-37
March 2000
Part No. 001-3139-502
900 MHz SYNTHESIZER SCHEMATIC
FIGURE 2-17
FOLDOUT
3
J201
+9V
C206
39
R246
100
4
1
2
+
C208
100
CR202
5.1V
C209
.01
+
C210
1
C212
.01
+
C213
1
+
C214
1
+
C215
1
+
C216
1
+
C217
1
C226
39
+9V DC
SOURCE
GND
AUDIO IN
LOCK DETECT OUT (0 = UNLOCKED)
DATA DEMULTIPLEXERS
13
14
15
12
1
5
2
4
INH
C
B
A
X
3
11
10
9
6
X0
X1
X2
X3
X4
X5
X6
X7
U201
4051
13
14
15
12
1
5
2
4
INH
C
B
A
X
3
11
10
9
6
X0
X1
X2
X3
X4
X5
X6
X7
U202
4051
13
14
15
12
1
5
2
4
INH
C
B
A
X
3
11
10
9
6
X0
X1
X2
X3
X4
X5
X6
X7
U203
4051
13
14
15
12
1
5
2
4
INH
C
B
A
X
3
11
10
9
6
X0
X1
X2
X3
X4
X5
X6
X7
U204
4051
D0
A
B
C
INH
D1
A
B
C
INH
D2
A
B
C
INH
D3
A
B
C
INH
RX (M5)
(M9)
A3
R3
R7
+5V
+5V
+5V
+5V
M1
R10
R6
R2
A6
A2
(MB)
M0
TX (M4)
R9
R5
R1
A5
A1
M3
RX (M7)
R8
R4
R0
A4
A0
M2
TX (M6)
R205
10k
1
2
3
4
1
2
3
4
5
6
7
S202
S203
+5V
R232
22k
+5V
Q202
3053
+9V
+
C211
15
CR205
OUT-OF-LOCK
R233
1.8k
DS0
DS1
DS2
ME
NC
D0
D1
D2
D3
PE
LD
15
16
17
13
OSC
OUT
9
10
11
12
A
B
C
INH
R222
10k
+5V
D0
D1
D2
D3
3
14
SYNTHESIZER
DRIVER
R223
47k
+5V
C218
47pF
R224
1M
C219
47pF
RESET
S201
P205
RX
TX
8
1
2
PDA
PDB
R292
1M
C221
33pF
CR204 CR203
R227
51k
R221
10k
R226
330k
R228
100k
+5V
R229
100k
C223
1
U206A
TL082
+
3
2
1
U206A
TL082
+
+2.5V
+
C222
47
+
C224
47
R241
10M
R242
10M
R225
47k
C221
33pF
19
RB
20
CH
REFERENCE
BUFFER
LOCK
SPEED-UP
INTEGRATOR
R231
10k
+
C225
1
TP201
R201
180k
CR201
CR290
R291
47k
R290
100k
C201
10pF
L201
R204
100
+9V
C202
.01
C207
.01
Q201
6014
C203
47pF
Y201
R202
390
R203
27
C204
51pF
R200
51
C200
47pF
J203
TO RECEIVER
OR EXCITER
R245
1k
+5V
Q205
3053
R244
22k
R243
10k
R248
270
C241
.01
1.25 MHz INPUT
FROM LO DRAWER
A201
J4 (RX)
J402 (EXCITER)
7
OSC IN
+5V
2,8
Vcc
1
3
MOD CTRL
U205
NJ8820
F
IN
18
4
MOD
CNTRL
OUTPUT
4
GND
5
IN
C227
.001
7
U207
8719
INPUT
R247
82k
C228
39pF
L205
R235
390
L205
Q203
3027
R239
3k
R236
51
Q204
3027
R237
270
C232
39pF
C233
39
R238
3.3k
C231
100pF
R234
10
C230
.001
+9V
R240
2.2k
C234
10pF
C235
39pF
L204
RF INPUT FROM
THIRD DOUBLER
(EXCITER OR RECEIVER)
J202
R206
10k
R207
10k
R208
10k
R209
10k
R210
10k
R211
10k
R212
10k
R213
10k
R214
10k
R215
10k
R216
10k
R217
10k
TX
RX
A0
A1
A2
A3
A4
A5
A6
M0
M1
M2
M3
NOTES:
1. ALL RESISTORS ARE IN OHMS AND ALL CAPACITORS IN MICROFARADS
UNLESS OTHERWISE SPECIFIED.
2. IC PINS NOT SHOWN:
U201, U202, U203, U204
IC
PIN NUMBER
U205
U206
U207
+5V GND
16
6
8
2,8
7,8
5
4
4
+9V