Motorola EP450 Service Manual

UHF 465-495 MHz PCB 8486634Z02 Schematic Diagrams, Overlays, and Parts Lists 11-45
HKLN4216A November 24, 2003
UHF R3 VCO
3.2V to 9.5V
4.5V
RX: 0V
TX: 3V
390pF
C275
L264
2%
8nH
C265
1.8%
5.6pF
390pF
C283
V_SF
NC
1SV229
D262
220nH
L255
TX_SWITCH
13
VCC_BUFFERS
14
VCC_LOGIC
18
R261
22K
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_LOGI C
PRESC_OUT
12
RX_BASE
5
RX_EMITTER
6
RX_IADJ
2
50U54
U251
COLL_RFIN
4
L251
220nH
NU
VCO_5R
L283
C273
.01uF
9.1pF
C254
3.0%
3.3pF
C255
1.1%
1%
33
R263
1
C257
12pF
SH251
SHIELD
390pF
C270
3.3%
3.0pF
C266
220nH
L265
R264
220nH
L270
100
C252
NU
33
R274
L252
27nH
C253
1.6%
6.2pF
R262
7.5K
390pF
C284
D261
C264
3.3%
3.0pF
C263
1.6%
6.2pF
R275
100
330
R273
R285
0
BFS540
Q280
1
3
2
VCO_TRB
D251
R271
5.1K
C281
390pF
VCO_V_STEER
C285
0.1uF
390pF
C292
VCO_TX_INJ
L254
2%
12.5nH
VCO_PRESC
R280
4.7K
2.5%
3.9pF
L292
C256
18nH
15nH
L282
18nH
L281
R282
910
NC
VCO_MOD
VCO_VSF
R283
130
9.1pF
1.1%
C267
C272
0.1uF
R284
NU
27nH
L276
0
R277
R276
VCO_3V
NU
150pF
C251
R281
8.2K
V_SF
L272
220nH
L291
6.8nH
100
R254
C276
2.8%
3.6pF
C286
2.5%
3.9pF
2.3%
4.3pF
C282
C290
1.5%
6.8pF
13pF
1%
C291
C271
L271
390pF
6.2K
R272
NU
SH253
SHIELD
1
0.1uF
SH250
SHIELD
1
C274
L262
27nH
C268
20%
0.5pF
V_SF
VCO_RX_INJ
47
R253
TX_IN J
5R
VCO_MOD
PRESC
V_STEE
R
RX_IN J
V_S F
3V
TRB
Figure 11-34. UHF (465-495 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)