Motorola Commercial Series Service Information page 41

VHF PCB 8486769Z02-A Schematic Diagrams
V_STEER
L251
VCO_V_STEER
560nH
3.0V to 8.0V
C251
.01uF
SH250
SHIELD
1
V_SF
V_SF
L270
4.5V VCO_VSF
560nH
C270
1200pF
R270
18
C271
D251
.01uF
C255
C253
18pF
16pF
1% 1%
L254
33nH
C256
C254
10pF
6pF
1.0%
L253
L252
100nH
560nH
L255
C257
36pF 330nH
1%
L262
560nH
D261
C263 C265
27pF 15pF
1% 1%
L264
47nH
C264
L263 10pF
100nH
V_SF
C268
2.7pF
3.7%
R262
6.8K
VCO_MOD
VCO_MOD
R261
36K
D262
1SV229
SH251 SH253
SHIELD SHIELD
1 1
3V
VCO_3V
C272
0.1uF
R272
9.1K
C273 R271
8.2K
.01uF
R274 L271
33 1
NU
TX_IADJ TX_OUT
2
RX_IADJ RX_OUT
3
SUPER_FLTR
4
COLL_RFIN PRESC_OUT
5
RX_BASE
6
U251
RX_EMITTER RX_SWITCH
16
TX_BASE TX_SWITCH
15
TX_EMITTER
20
R254
FLIP_IN
19
220
TRB_IN
C258
1200pF
R253
47
C266
10pF
1.0%
R264
220
C269
1500pF
V_SF
R263
30
C267
L265
36pF
1% 330nH
TRB
R275
TX: 3V VCO_TRB
RX: 0V 0
C275
1200pF
R273
300
C292
1200pF
C274 C285
0.1uF 0.1uF
L282 R284
L292
47nH
680
68nH
10
8
C290
51pF
12
206 mV (RF)
7 L291
NC
27nH
13
NC
L281
68nH
5R
VCO_5R
R281
C284
1200pF 9.1K R282
C281
750
1200pF
1.89 V (Rx)
C286 R286
0
11pF
R280
6.8K
L283
NU
PRESC
R276 L276 C277 VCO_PRESC
100nH
1K 1200pF
C276
5.1pF
VHF (136-162 MHz) Voltage Controlled Oscillator Schematic
4-9
1200 mV (RF)
TX_INJ
VCO_TX_INJ
C291
43pF
850 mV (RF)
RX_INJ
C282
VCO_RX_INJ
3
9.1pF
1
Q280
BFS540
2
1.35 V (Rx)
R283 C283
1200pF
180