Schematic Diagram - Sony ICF-C793 Service Manual

4-3.

SCHEMATIC DIAGRAM

– 13 –
• IC Block Diagrams
– MAIN BOARD –
IC1 CXA1019M
14
15
IC50 BU2614FS
16
PHASE
DETECT
2 IC100 !ª (XT1)
1 V/DIV, 20 µs/DIV
• Waveforms
– MAIN BOARD –
1 IC50 2 (X IN) 3 IC100 @™ (X1)
1 V/DIV, 10 µs/DIV 1 V/DIV, 500 ms/DIV
1.9 Vp-p
13.3 µ s
– 14 –
13 12 11 10 9 8 7 6 5 4 3 2 1
FM FE
FM
DISCRIMINATOR
FM IF
AM FE
AF POWER AMP
TUNING METER
AM IF DET AGC
16 17 18 19 20 21 22 23 24 25 26 27 28
15 14 13 12 11 10 9
Note on Schematic Diagram:
MAIN CONTROL IF
• All capacitors are in µF unless otherwise noted. pF: µµF
PRESCALLER COUNTER
50 WV or less are not indicated except for electrolytics
and tantalums.
• All resistors are in Ω and
OUTPUT
I/O CONTROL
CONTROL specified.
REGISTER
• ¢ : internal component.
• C : panel designation.
Note:
1 2 3 4 5 6 7 8
The components identi-
fied by mark ! or dotted
line with mark ! are criti-
cal for safety.
Replace only with part
number specified.
• U : B+ Line.
• H : adjustment for repair.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM
( ) : AM (MW/LW)
• Voltages are taken with a VOM (Input impedance 10 MΩ).
2 Vp-p
Voltage variations may be noted due to normal produc-
tion tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
• Circled numbers refer to waveforms.
30.5 µ s
• Signal path.
F : FM
f
: AM (MW/LW)
• Abbreviation
AUS : Australian model
CND : Canadian model
FR : French model
2 Vp-p
Note:
• Press either [+] or [–] key when RADIO is being
operated, oscillation will be given out for 250 ms.
• Oscillation will be given out for 250 ms when the
power is turned on.
238.7 ns
– 15 –
ICF-C793/C793L
1
/ W or less unless otherwise
4
Note:
Les composants identifiés par
une marque ! sont critiques
pour la sécurité.
Ne les remplacer que par une
piéce portant le numéro
spécifié.