Sony CFM-A50 Service Manual ▷ View online
– 9 –
TUNER SECTION
AM Section
Function switch : RADIO
Band switch
Band switch
: AM (US model)
MW or LW (AEP, UK model)
MW or LW (AEP, UK model)
Volume
: MIN
FM Section
Function switch : RADIO
Band switch
Band switch
: FM
Volume
: MIN
• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
done by the trimmer capacitors.
( ) : AEP, UK only
AM IF ALIGNMENT
Adjust for a maximum reading on level meter.
T1
455kHz
AM (MW) FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L3
520kHz
CT1 – 2
1,780kHz
(1,680kHz)
AM (MW) TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L6 (L6 – 1)
620kHz
CT1 – 1
1,400kHz
Tape Speed Adjustment
Procedure :
1. Mode : Playback (Normal Speed)
Procedure :
1. Mode : Playback (Normal Speed)
2. Adjust RV103 so becomes the adjustment value below.
3. Set to slow playback switch (S105) ON mode.
3. Set to slow playback switch (S105) ON mode.
Confirm that the become adjustment value as to follows.
Adjustment Value :
Speed checker
Digital frequency counter
–1 to +1%
2,970 – 3,030Hz
Frequency difference between the beginning and the end of the tape
should be within 1.5% (45Hz).
should be within 1.5% (45Hz).
Adjustment Location :
set
test tape
WS-48B
(3kHz, 0dB)
WS-48B
(3kHz, 0dB)
32
Ω
speed checker
LFM-30 or
digital frequency
counter
LFM-30 or
digital frequency
counter
J101 (Earphone jack)
[DECK CONTROL BOARD]
(Component side)
(Component side)
RV103 : Tape speed Adjustment
AM RF signal
generator
generator
30% amplitude modulation by 400Hz
signal.
Output level : as low as possible
signal.
Output level : as low as possible
Put the lead-wire
antenna close to
the set.
antenna close to
the set.
set
32
Ω
J101 (Earphone jack)
level meter
FM RF signal
generator
generator
22.5kHz frequency deviation by
400Hz signal.
Output level : as low as possible
400Hz signal.
Output level : as low as possible
telescopic
antenna
terminal
antenna
terminal
0.01
μ
F
set
32
Ω
J101 (Earphone jack)
level meter
– 10 –
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L2
86.5MHz
(87MHz)
CT1 – 4
109.5MHz (108.30MHz)
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1
86.5MHz
(87MHz)
CT1 – 3
109.5MHz (108.30MHz)
AEP, UK model
LW FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L4
145kHz
CT6
300kHz
LW TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L6 – 2
145kHz
CT5
300kHz
Adjustment Location : MAIN board (Component side)
[MAIN BOARD] (Component side)
CT1–3 : FM Tracking Adjustment
CT1–1 : MW Tracking Adjustment
CT5 : LW Tracking Adjustment
L6–2: LW Tracking Adjustment
L6–1: MW Tracking Adjustment
T1 : AM IF Alignment
L2 : FM Frequency Coverage Adjustment
CT1–2 : MW Frequency Coverage Adjustment
CT1–4 : FM Frequency
Coverage Adjustment
Coverage Adjustment
L3 : MW Frequency Coverage Adjustment
CT6 : LW Frequency
Coverage Adjustment
Coverage Adjustment
L4 : LW Frequency
Coverage Adjustment
Coverage Adjustment
L1 : FM Tracking Adjustment
[MAIN BOARD] (Component side)
CT1–3 : FM Tracking Adjustment
CT1–1 : AM Tracking Adjustment
L6 : AM Tracking Adjustment
T1 : AM IF Alignment
L2 : FM Frequency Coverage Adjustment
CT1–2 : AM Frequency Coverage Adjustment
CT1–4 : FM Frequency
Coverage Adjustment
Coverage Adjustment
L3 : AM Frequency Coverage Adjustment
L1 : FM Tracking Adjustment
AEP, UK model
US model
– 11 –
r
CIRCUIT BOARDS LOCATION
MAIN board
BATTERY board
DECK CONTROL board
TACT SW board
H/P JACK board
TUN LED board
POWER board
VOLUME board
ISS SW board
(AEP, UK model)
(AEP, UK model)
SECTION 5
DIAGRAMS
– 12 –
– 14 –
– 13 –
Note:
• All capacitors are in
• All capacitors are in
µ
F unless otherwise noted. pF:
µµ
F
50 WV or less are not indicated except for electrolytics
and tantalums.
and tantalums.
• All resistors are in
Ω
and
1
/
4
W or less unless otherwise
specified.
Note: The components identified by mark
!
or dotted
line with mark
!
are critical for safety.
Replace only with part number specified.
•
U
: B+ Line.
•
H
: adjustment for repair.
• Power voltage is dc 6 V and fed with regulated dc power
supply from external power voltage jack.
5-1. SCHEMATIC DIAGRAM (AEP,UK MODEL)
r
Refer to page 26 for IC Block Diagrams.
CFM-A50
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM
(
no mark : FM
(
) : MW, LW
• Voltages are taken with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Signal path.
F
: FM
E
: PB
a
: REC
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