— 7 —
— 8 —
4-1. WAVEFORMS
4-2. IC BLOCK DIAGRAMS
THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS
AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed in each
block.)
NOTE
•
: parts extracted from the component side.
•
: parts extracted from the conductor side.
•
: Pattern from the side which enable seeing.
NOTE
• All capacitors are in
µ
F unless otherwise noted. pF :
µµ
F 50WV
or less are not indicated except for electrolytics and tantalums.
• All resistors are in
Ω
and 1/4W or less unless otherwise speci-
fied.
•
¢
: Internal component.
•
: nonflammable resistor.
•
: panel designation.
3
6
11
2
5
8
1
4
14
15
12
9
10
16
13
7
FM IF AMP
LIMITER
AF/NULL
METER
QUADRATURE
DET
AF AMP
IF OFF
NULL METER
SHORTING
LEVEL
DET
METER
DRIVE
MUTING
CIRCUIT
DETUNE
DET
GND
B+
IC401 LA1245
3
6
9
2
5
8
1
4
7
10
18
15
12
19
16
13
20
17
14
11
AM RF AMP
AM IF AMP
AM
MIXING
AGC
AM
OSC
GND
B+
(RF)
AM DET
METER
DRIVE
B+
(IF)
1
FM/AM SELECT
MUTING
FM/AM SELECT CONTROL
LOGIC / MUTE ON/OFF
MUTING
OUT
LAMP
DRIVE
PLL
VCC
GND
MPX
22
21 20 19 18 17 16
15
14
13
12
2
3
4
5
6
7
8
9
10
11
IC301 LA3401
IC221, 251 LA1235
1
2
3
4
REG
GND
CONTROL
REG
5
6
7
IC901 LA5667
TEST LOGIC AND OUTPUT
SELECTOR SWITCH
QUALITY BIT
GENERATOR
OSCILLATOR
AND
DIVIDER
RECONSTRUCTION
FILTER
57KHz
BANDPASS
(8th ORDER)
ANTI-
ALIASING
FILTER
COSTAS LOOP
VARIABLE AND
FIXED DIVIDER
CLOCKED
COMPARATOR
CLOCK REGENERATION
AND SYNC
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
REFERENCE
VOLTAGE
DIFFERENTIAL
DECODER
BIPHASE
SYMBOL
DECODER
Vp1
QUAL
RDDA
VREF
MUX
VDDA
VSSA
CIN
SCOUT
RDCL
T57
OSCO
OSCI
VDDD
VSSD
TEST
TSTLD
IC801 SAA6579
SECTION 4
DIAGRAMS
IC801
!£
4.332MHz
MAIN SECTION
1
3.2Vp-p
IC701
!¡
X2
4.2MHz
DISPLAY SECTION
1
5.2Vp-p
•
B+
: B+ Line
•
B–
: B– Line
•
: adjustment for repalf
• Voltage and waveforms are dc with respect to ground under no-
signal conditions.
no mark : FM
MW
: ( )
LW
: < >
*
: Can not be measu
• Voltages are taken with a VOM (Input impedance 10M
Ω
).
Voltage variations may be noted due to normal production toler-
ances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal production toler-
ances.
• Circled numbers refer to waveforms.
• Signal path.
: FM
: AM
Note: The components identified by mark
!
or dotted
line with mark
!
are critical for safety.
Replace only with part number specified.
