Kenwood NX-300 Service Manual page 87

BD
TX-RX UNIT (X57-7370-XX) (A/2)
THP
1 /T R
50C
IC500
TEMPERATURE SENSOR
+B
LM73CIMKX-0
4
I2CCK SMBCLK
5
ALERT
6
I2CSDA SMBDAT
VC
GND
33C
TCXO MOD
AF AMP for
TCXO MOD
R570 0
50T
2
50R
R527
50IF
D501,Q503
RIPPLE FILTER DC AMP for VCO TUNE
R : 14.34V R : 13.73V
T : 14.43V T : 13.82V
Q503
2SC5383-T111
150C
1
2
3
R : 14.33V
T : 14.41V
∗
∗
3
4
BE
SCHEMATIC DIAGRAM
D514 D515
X57-7370-XX D510 L520
-10 K,K3 1SV282-F 1SV282-F 1SV282-F 18n
K2,K4
-11 1SV290B-F 1SV290B-F 1SV290B-F 22n
X57-7370-XX R958 C516 C529 C537 C543 C545 C547
5p
-10 K,K3 NO 0.01u 100p 3p NO 100p
4p 470p 470p
-11 K2,K4 0 NO NO NO
IC500
R572
3
VDD
2 10
GND
1
ADDR
R503
10
VCC
L500
oUTPUT
4.7u
X500
19.2MHz
∗ ∗
R935 R573
∗
R502
IC501
TLV2381ID8V
1 OUT 5
VDD
2
R504 C511
GND
100k 10u
3 4
IN+ IN-
C503
0.1u
BUFFER AMP
CN500
CV
Q504
L508
2SK879-F (Y)
220n
R537
1k
L503
R532 R538
0 0 390
L509
R576
220n
0
BYPASS
DIODE
D505
DA221
IC503
TLV2381ID8V
OUT
5
VDD
R539
GND
10M
R566
4
IN+ IN-
470k
C529
C563
BF
L521 L528 R502 R533 R552 R559 R561 R573 R583
22n 27n 120k 180k 120k 180 180 NO NO
27n 33n NO 220k 100k 220 220 120k 0
C553 C557 C561 C563 C566 C567 C568 C573 C574
5p 4p 1p
100p NO NO 68p NO NO
10p 470p 100p 82p 0.5p 1.5p 6p 2p
0.01u
C525
47p
C515
∗
R955 0.01u
R586
0
13
LD/PS2
L599
14
∗
R956
VCC cp2
15
CPout2
∗
R957
16
/Fvco
17
∗
R958
Fvco
18
VCCcp2
L598
R511 10
SDO1
R512 10
/PCS_RF
R513 10
SCK1
PLD
R : 4.15V
T : 18mV
D506,510,514,515
FREQUENCY CONTROL
RX VCO
∗ ∗
∗
C556 R575 D510 C566 L521
470p 0
R : 2.5mV
T : 4.2V
TX VCO
∗
∗ D511 L520
C557 C565
33p
1SV282-F
D507,511,516,517
D519
R : 4.27V
FREQUENCY CONTROL
TX
T : 4.28V
MODULATION
C562
∗
1u R552
OP AMP
R : 4.978V
(VCO MOD/APC) R : 1.4V
T : 5.06V
T : 4.38V
IC504
Q507
TC75W51FUF
2SC5383-T111
1 8
VDD
7
2
R670
3 6
4 5
220k
RIPPLE
VSS
FILTER
C600
0.1u
APC
BG
NX-300
R935 R955 R956 R957
NO NO NO NO
15k 0 0 0
C575 C586 C987
7p
3p NO
6p 10p 5p
∗
C543
∗
L504 C553 R577
12n 0
∗
R583
C514
IC502
0.01u
SKY72300-362
PLL IC
6
CPout1
R522
5
VCCcp1
10
4
LD/PS1
C521 C526
3
/Fin
100p 0.1u
2
Fin
C527
R519
1
VCC
100p
10
C522
0.1u
C523
100p
C517 100p
C518 100p
C519 100p
L522
R560
Q512
220n
∗ 22
C573
BUFFER AMP
C581
0.5p
R : 1.11V (K,K3)
R : 0.96V
0.97V (K2,K4)
T : 0.43V
T : 18mV
R : 4V
Q508
T : 4.03V
2SK508NV(K52)
R564
VCO
OSCILLATION
150k
L527
L524
220n
C576
2SC5636
5p
C583
0.5p
R : 2.5mV
T : 1.01V (K,K3)
0.87V (K2,K4)
Q509
2SK508NV(K52)
VCO
OSCILLATION
2SJ347F
Q510
SSM6L05FU-F
R : 4.26V
T : 6.94mV
R558
470k
Q510,511
T/R
SWITCH
R568
R : 3.25V
470k T : 9.7mV
R : 0.15mV
T : 1.84mV
RIPPLE FILTER
R : 0.14mV
T : 4.08V
X57-737 (A/2) 2/4
BH
THP
50T
TX
R550 C588
0 10p
50C
+B
33C
3
19.2M
Q512
R : 1mV
T : 4.17V
Q511
3
50R
50IF
4
150C
87