Motorola EP450

VHF 146-174 MHz PCB 8486342Z13-C Schematic Diagrams, Overlays, and Parts Lists 6-9
HKLN4216A November 24, 2003
4.5V
RX: 0V
TX: 3V
VHF R2 VCO
3.0V to 8.0V
1K
NC
R276
100nH
L253
9.1K
R281
L292
68nH
1200pF
C277
SHIELD
SH251
1
R262
6.8K
R273
300
R275
SH253
SHIELD
1
0
L271
D261
220
NU
560nH
R254
330nH
L270
0
L255
27nH
L291
R286
C263
1%
27pF
C251
.01uF
8.2K
R271
18pF
1%
C255
C265
1%
15pF
L263
100nH
C291
36pF
L276
100nH
C257
1%
36pF
VCO_5R
560nH
VCO_TRB
VCO_PRESC
L251
VCO_RX_IN
J
NC
C270
1200pF
VCO_3V
51K
R261
VCO_V_STEER
C258
1200pF
V_SF
1200pF
C281
C292
1200pF
R264
220
R284
330
2.7pF
3.7%
C268
.01uF
C273
5.1pF
C276
9.1K
R272
6.8K
R280
1%
16pF
51pF
C253
47nH
2%
L264
C290
Q280
BFS540
1
3
2
30
L262
R263
0.1uF
C272
560nH
TX_OUT
13
TX_SWITCH
14
VCC_BUFFERS
18
VCC_LOGI C
D251
RX_IADJ
8
RX_OUT
7
RX_SWITCH
3
SUPER_FLTR
TRB_IN
19
16
TX_BASE
15
TX_EMITTER
1
TX_IADJ
10
COLL_RFIN
20
FLIP_IN
11
GND_BUFFERS
9
GND_FLAG
GND_LOGIC
17
12
PRESC_OUT
5
RX_BASE
6
RX_EMITTER
2
U251
50 U54
4
C269
1500pF
36pF
1%
C267
C283
1200pF
V_SF
C284
1200pF
R274
33
V_SF
C254
3.0%
3.3pF
VCO_TX_INJ
R283
180
C275
1200pF
.01uF
SHIELD
SH250
1
C271
L282
47nH
0.1uF
C285
0.1uF
C274
L281
68nH
33nH
2%
L254
C264
2.1%
4.7pF
R282
C256
1.0%
10pF
750
18
VCO_VSF
R270
560nH
L252
L283
VCO_MOD
10pF
1.0%
C266
NU
9.1pF
R253
47
C282
11pF
C286
330nH
L265
D262
1SV229
V_S F
V_STEER
PRESC
VCO_MOD
5R
TX_INJ
RX_INJ
3V
TRB
3
3
1
1
2
2
Figure 6-7. VHF (146-174 MHz) Voltage Controlled Oscillator Schematic Diagram