SECTION 4
BLOCK DIAGRAM
COMPRESSOR
PRE AMP
ELECTRET
AU-258 BOARD
CONDENSER
MICROPHONE
IC101(1/2)
IC102
X102
32.768 kHz
IC105(4/6)(5/6)
X101
32.782 kHz
X’
TAL OS C
f
L P
F
PRE
EMPHASIS
RF AMP
LED
DRIVER
BATT
INDICATOR
IC101(2/2)
C125, R122
AF
SWITCH
IC107
D/A
CONVERTER
IC105(3/6)
D301
Q302
PLL
IC401
LOCK
DETECTOR
Q401
Q404, 405
D402
ISOLATOR
CP402
LPF
FL401
ANTENNA
1/4
λ
HELICAL
CPU
POWER
LR6
x
1
4.0MHz
IC301
IC303
RESET
IC304, 305
Q301
POWER
CONTROL
Q203
D201, 202
VOLTAGE
COMPARATOR
IC306, 307
1.5V
Vcc1 (3V)
Vcc2 (3V)
VOLTAGE
CONTROLER
DC-DC
CONVERTER
IC201
Q201, 202
Q402, 403
D403
S201
S301
S302
BATTERY
CHANNEL SELECT
SWITCH
EEPROM
IC302
X301
CN101
LIMITTER
IC103, 104
Q101, D101
RV101
VCO
CP401
CLAMPER
Q102, 103
D102, 103
RV102
LPF
Q104
X’
TAL OS C
BUFFER
IC105(2/6)(6/6)
IC105(1/6)
IC106
RV103
LPF
Q105
BUFFER
IC108
RV104
RF-87 BOARD
X’
TAL OS C
CT301
S303
S304
RV401
CT401
CN401
f
(Vcc 2)
f
f
SL301
302
303
304
CN103
4-1
WRT-800A (AU)