Motorola Commercial Series Service Information page 41

UHF2 PCB 8486348Z13-C Schematic Diagrams
V_SF
VCO_VSF
L270
4.5V
V_S F
220nH
SH250 SH251
SHIELD SHIELD
1 1
VCO_V_STEER
L251
V_STEE R
220nH
3.2V to 9.5V
C251 C252
150pF NU
VCO_MOD R261
VCO_MOD
22K
VCO_TRB
R275
TR B
100
RX: 0V
TX: 3V
C270
390pF
L272
220nH
SH253
SHIELD
1
C271
R274
33
390pF
C253 C255
5.6pF
6.2pF
L252
27nH
1.6% 0.1%
C254 C256
L254
D251
12.5nH
5.1pF 3.9pF
2%
2%
2.5%
C257
12pF
1%
C263
4.7pF C265
L262
27nH
3.3pF
2.1%
C264
L264 3.0%
D261
12.5nH
2pF
2%
5% C268
V_SF
0.5pF
D262
1SV229
UHF R2 VCO
R273
330
C274
0.1uF
VCO_3V
3V
C272
0.1uF
C273
R271 R272
5.1K 5.6K
.01uF
L271
NU
1
TX_IADJ
2
RX_IADJ
3
SUPER_FLTR
4
COLL_RFIN
5
RX_BASE
6
RX_EMITTER
16 TX_BASE
15
TX_EMITTER
20 FLIP_IN
19
R253 TRB_IN
33
R254
100
L255
220nH
C266
2.4pF
0.1%
R263
33
C267
R262
R264
6.8K
100
7.5pF
1.3%
L265
220nH
C275
390pF
R277
C292 0
C285
R284
L282
390pF
15nH 220
0.1uF
L292
15nH
10
TX_OUT
8
RX_OUT
7
NC
RX_SWITCH
13
TX_SWITCH NC
U251
4 50U5
VCO_5R
12
L281
PRESC_OUT
5R
27nH
C284
390pF
C286
R285
0
6.2pF
L283
NU
V_SF
R276
L276
27nH
1K
C276
6.8pF
UHF2 (438-470 MHz) Voltage Controlled Oscillator Schematic
4-9
C290 VCO_TX_INJ
TX_IN J
6.8pF
C291
L291
6.8nH 18pF
R281
8.2K
R282
C281 C282
910 VCO_RX_INJ
RX_INJ
3.3pF
390pF
3
1
Q280 2
BFS540
C283
R280
R283
4.7K
150
390pF
VCO_PRESC
PRESC