Motorola EP450 Service Manual

UHF 403-440 MHz PCB 8486635Z03-O Schematic Diagrams, Overlays, and Parts Lists 11-9
HKLN4216A November 24, 2003
UHF R1 VCO
3.2V to 9.5V
4.5V
RX: 0V
TX: 3V
TX_SWITCH
13
VCC_BUFFERS
14
VCC_LOGIC
18
RX_OUT
8
RX_SWITCH
7
SUPER_FLTR
3
19
TRB_IN
TX_BASE
16
TX_EMITTER
15
TX_IADJ
1
TX_OUT
10
FLIP_IN
20
GND_BUFFERS
11
GND_FLAG
9
17
GND_LOGIC
PRESC_OU T
12
RX_BASE
5
RX_EMITTER
6
RX_IADJ
2
50U54
U251
COLL_RFIN
4
L251
220nH
NU
VCO_5R
L283
C273
.01uF
5.6pF
C254
1.3%
7.5pF
C255
1.8%
33
R263
1
390pF
C275
SH251
SHIELD
390pF
C270
3.0%
3.3pF
C266
220nH
L265
3.0%
3.3pF
220nH
L270
C286
C265
10pF
1.0%
8.2pF
C257
390pF
C283
1SV229
D262
C290
6.8pF
13pF
C291
C271
L271
390pF
R272
NU
1
5.6K
0.1uF
SH253
SHIELD
SH250
SHIELD
1
C274
L262
27nH
C268
20%
0.5pF
VCO_RX_IN
J
R253
V_SF
4.7K
33
2%
12.5nH
R280
C256
2.8%
3.6pF
L264
33nH
V_SF
910
NC
L281
L255
R282
22K
NC
220nH
130
R261
R283
6.8pF
1.5%
C267
C272
0.1uF
L276
R284
330
R277
27nH
R276
NU
0
C251
0888600M03
VCO_3V
8.2K
150pF
220nH
R281
V_SF
L272
L291
6.8nH
100
R254
C252
C276
3.9pF
NU
L252
27nH
3.6pF
C282
R262
6.8K
390pF
C284
D261
R264
2%
5pF
100
100
C263
R273
R275
0
330
1
3
2
R285
VCO_TRB
BFS540
Q280
D251
4.7K
R271
VCO_V_STEER
0.1uF
C281
390pF
390pF
C292
C285
VCO_TX_INJ
L254
2%
12.5nH
VCO_PRESC
C264
3.0%
3.3pF
15nH
L292
VCO_MOD
L282
15nH
VCO_VSF
33
R274
1.6%
6.2pF
TX_INJ
C253
5R
VCO_MOD
PRESC
V_STEER
RX_INJ
V_SF
3V
TRB
Figure 11-7. UHF (403-440 MHz) Voltage Controlled Oscillator Schematic Diagram

Motorola EP450 Specifications

General

Channel Capacity	16 channels
Operating Temperature	-30°C to +60°C
IP Rating	IP54
Frequency Range	VHF: 136-174 MHz, UHF: 403-470 MHz
Weight	Approximately 350g (with standard battery)