Sony SRFPSY-04 Service manual
SRF-PSY04
SERVICE MANUAL
Ver 1.0 1999. 06
Photo: Blue model
SPECIFICATIONS
US Model
MICROFILM
FM STEREO/AM PLL
SYNTHESIZED RADIO
TABLE OF CONTENTS
3
1. GENERAL ................................................................... 3
2. DISASSEMBLY ......................................................... 4
3. ELECTRICAL ADJUSTMENTS......................... 5
4. DIAGRAMS
4-1. Block Diagram ................................................................ 7
4-2. Printed Wiring Boards..................................................... 9
4-3. Schematic Diagram ......................................................... 11
4-4. IC Pin Function Description ........................................... 15
5. EXPLODED VIEW................................................... 16
6. ELECTRICAL PARTS LIST ............................... 17
HOW TO CHANGED THE CERAMIC FILTERS
This model is used two ceramic filters of CF1 and CF3.
Y ou must use same type of color marked cer amic filters in order to
meet same specifications.
Therefore, the ceramic filter must be changed two pieces together
since it’s supply two pieces in one package as a spare parts.
Mark Center frequency
CF
mark
CF1
Notes on chip component replacement
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be damaged by heat.
red 10.70 MHz
blue 10.67 MHz
orange 10.73 MHz
black 10.64 MHz
white 10.76 MHz
– 2 –
SECTION 1
GENERAL
This section is extracted from
instruction manual.
– 3 –
SECTION 2
DISASSEMBLY
Note: Follow the disassembly procedure in the numerical order given.
FRONT CABINET
3
two claws
4
front cabinet
3
two claws
2
MAIN BOARD, KEY BOARD
two screws
(P2
×
8)
2
KEY board
2
MAIN board
1
lid, battery case
1
two claws
– 4 –
SECTION 3
r
d
µ
)
ELECTRICAL ADJUSTMENTS
0 dB=1 µV
[AM]
Setting:
BAND switch: AM
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
Output level: as low as possible
[FM]
Setting:
BAND switch: FM
FM SENS switch: DX
FM RF signal
generator
22.5 kHz frequency
deviation by 400 Hz
signal
Output level: as low as possible
• Repeat the procedures in each adjustment several times, and the
tracking adjustments should be finally done by the trimmer capacitors.
MAIN board
TP (VT)
Put the lead-wire
antenna close to
the set.
MAIN board
TP (ANT)
0.01 µF
digital voltmete
+
–
set
set
level meter
16
Ω
+
–
(headphones) jack (J1)
2
level meter
16
Ω
+
–
2
(headphones) jack (J1)
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T1 450 kHz
AM FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L5 530 kHz 2.7 ± 0.1V
Confirmation 1,710 kHz 8.9 ± 1V
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L2 580 kHz
CT1 1,490 kHz
FM VCO VOLT A GE CONFIRMATION
Frequency Display Reading on Digital Voltmeter
87.5 MHz 2.7 ± 0.1V
108 MHz 8.9 ± 1V
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3 87.5 MHz
CT2 108 MHz
FM STEREO (76 kHz) Adjustment
Setting:
BAND switch: FM
FM SENS switch: DX
FM RF signal
generator
0.01 µF
MAIN boar
TP (ANT)
set
Adjustment Location: Main Board (See page 6)
Carrier frequency : 98 MHz
Modulation : 1 kHz, 22.5 kHz deviation
Output level : 562
V (55 dB
Procedure:
1. Connect the frequency counter to TP (76 kHz) as shown the
figure below.
2. Tune the set to 98 MHz.
3. Adjust RV1 for 76 kHz reading on the frequency counter.
Specification: 75.5 to 76.5 kHz
frequency
counter
MAIN board
TP (76 kHz)
1 µF
+
+
–
Adjustment Location: MAIN board (See page 6)
– 5 –
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