Schematic Diagram - Kenwood TM-281A Service Manual

A
TM-281A
TX-RX UNIT (X57-8130-XX)(A/2) : TX-RX SECTION
1
R4 1k
R3 1k
R2 1k
R5 TCXO
X1
10k
C1
VC
+DC
22u
16.8MHz
GND
OUTPUT
2
L77-1944-05
3
4
R835
5
R836
R837
R838
6
7
36
X57-813 (A/2) 1/3
B

SCHEMATIC DIAGRAM

Q1,2
SWITCHING
D1 R10
Q1
8.2k
HZU5ALL
2SA1832(GR)F
VOLTAGE Q2
DROPPED R11 2SC4738(GR)F
10k
PLL IC
IC1
MB15A02PFV2E1
C21
L2 C14
470p
10u
C15
R:4.93V 0.1u
R:2.29V
10u
RIPPLE
FILTER
R8
100k
R:4.94V
DT(CPU53)
CK(CPU54)
FRQO
5C
R:2.21V
R722
1.5k
5C
R:5.00V
IDC
R:2.50V
R721
C732
Q701
2SC4919-S C726
C733
0.1u
AGC/
MIC MUTE
D709
R:0.76V
1SS372F
R716
100
R:0.76V
DETECTION
8C
MIC MUTE
R:1.47V
X57-8130-XX C726 C732 C734 R717 R721
-10 K 0.039u 1000p 0.022u
18k 750k
-21 M2 0.039u 1000p 0.022u
18k 750k
-22 M3 0.039u 1000p 0.022u
18k 750k
-23 M4 0.068u 680p 0.039u
10k 1M
C
R9
470
D3,5
CV
VCO
FREQENCY
CONTROL
L6
R15 R19 L5 D5
R21
270n
1k 2.7k 1.5k HVC359
D4,6
VCO
FREQENCY
RF AMP CONTROL
Q3 R:0.71V D6
2SC4649(N,P) L7
HVC359
R16
270n
0
L10
R25
47k
IC705
M62363FP-F
DIGITAL
POTENTIOMETER
5C
R743
5.00V R744
R745
C738 R726
0.1u 18k
C735 68p
R725 R728
R730
240k 82k 82k
IC704
NJM12904RB1
SPLATTER FILTER
OP AMP
HPF
8C
C752
IC703
NJM2100V-ZB 3900p
R738 R740
OP AMP
68k 68k
C745
39p
R734
220k
1/2Vcc
8C
R:7.81V
R:3.35V
R835 R836 R837 R838
0 NO NO
NO
NO 0 NO NO
NO NO
0 NO
NO
NO NO 0
D
RX VCO
R:0.73V
OSCILLATOR
T:0.72V
C49 4.5p
R:5.85V R:1.07V
Q4
C54
C36 MCH3914(7)-H
L12
33n
30p 0.3p
T/R SWITCH
R29
470
Q5
T:6.77V 2SJ347F
R28
220
R:6.85V
TX VCO
C50
10p
T:3.68V
T/R SWITCH
T:0.77V
Q6
C35 L11
MCH3914(7)-H
82p 47n C55
0.5p
R:7.82V
OSCILLATOR
D7
VCO
MODULATION
R27
47k
RIPPLE
FILTER
R26
8CL
47k
UL(CPU21)
PLLE(CPU3)
MOD
1k
1k
1k
OP AMP
IC706
BA10324AFV
1
14
2
13
3
12
4
11
VCC VEE
5
10
6 9
7
8
R737 R739
10k 22k
BEAT
SHIFT
L78-1427-05 BEAT
SWITCH
SHIFT
X701
Q702 C767
C763
R758 SWITCH
2SC4919-S
3p 0 3p
R756
R762
10k 10k
Q703
2SC4919-S
BEAT SHIFT ON:4.87V
BEAT SHIFT OFF:0V
E
BUFFER AMP
R:6.03V
Q9
2SC5108(Y)F
C60
6p
R:6.91V
Q7
UMC4N
L17
R34
1k
R:4.84V
T:0V
RIPPLE
FILTER
Q8
KTC4075E(Y,GR)
R:7.59V
DT(CPU53)
CK(CPU54)
PC/TV
MIC
W/NO(EVOL2)
W/NI(EVOL1)
VOLO(EVOL15)
VOLI(EVOL13)
BRI
MICMT(CPU77)
R749
5.6k
R829
0
R828
0
PLLE(CPU3)
QT/DQT(CPU1)
EVLLD(CPU8)
TX/RX (CPU20)
UL(CPU21)
TX DTMF
XOUT(CPU11)
XIN(CPU13)
BSHIFT
1/2Vcc