Read Sony SRF-QT1 Service Manual online
SRF-QT1
— 5 —
— 6 —
• Repeat the procedures in each adjustment several times.
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1
86.5MHz
CT1
109.5MHz
FM VCO Adjustment
Procedure :
1. Connect frequency counter to the positions shown below.
2. Tune the set to 98 MHz.
3. Adjust L4 so that the value of the frequency counter reading
2. Tune the set to 98 MHz.
3. Adjust L4 so that the value of the frequency counter reading
becomes 38 kHz.
Specification Value :
Frequency counter
37.95 – 38.05 kHz
0dB=1µV
Adjustment Location:
MAIN board (Side B)
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L6
86.5MHz
CT2
109.5MHz
SECTION 3
ELECTRICAL ADJUSTMENT
0.01
µ
F
FM RF signal
generator
generator
to ANT (TP6)
75kHz (100%) amplitude modulation
by 1kHz signal.
Output level : as low as possible
by 1kHz signal.
Output level : as low as possible
16
Ω
Set
+
–
Level meter
Headphones jack (J1)
0.01
µ
F
FM RF signal
generator
generator
to ANT (TP6)
Carrier frequency : 98MHz
Modulation : no modulation
Output level : 0.1V (100dB)
Modulation : no modulation
Output level : 0.1V (100dB)
Frequency counter
1
µ
F
+
–
100k
Ω
TP9
TP (GND)
TP8
10
µ
F
SECTION 4
DIAGRAMS
• IC BLOCK DIAGRAMS
IC1
CXA1129N
IC3
LA4535M
Note on Printed Wiring Board:
• X
: parts extracted from the conductor side.
•
: parts extracted from the component side.
•
a
: Through hole.
• b
: Pattern from the side which enables seeing.
Caution:
Pattern face side:
Pattern face side:
Parts on the pattern face side seen from
(SIDE A)
the pattern face are indicated.
Parts face side:
Parts on the parts face side seen from
(SIDE B)
the parts face are indicated.
Note on Schematic Diagram:
• All capacitors are in µF unless otherwise noted. pF: µµF
• All capacitors are in µF unless otherwise noted. pF: µµF
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.
•
C
: panel designation.
•
U
: B+ Line.
•
H
: adjustment for repair.
• Power voltage is dc 1.5 V and fed with regulated dc power
supply from battery terminal.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM
no mark : FM
• 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
FM 2nd OSC Adjustment
Procedure :
1. Connect frequency counter to the positions shown below.
2. Tune the set to 98 MHz.
3. Adjust L2 so that the value of the frequency counter reading
2. Tune the set to 98 MHz.
3. Adjust L2 so that the value of the frequency counter reading
becomes 57.1 MHz.
Specification Value :
0.01
µ
F
FM RF signal
generator
generator
to ANT (TP6)
Carrier frequency : 98MHz
Modulation : no modulation
Output level : 0.1V (100dB)
Modulation : no modulation
Output level : 0.1V (100dB)
Frequency counter
1
µ
F
+
–
100k
Ω
TP10
TP (GND)
TP8
10
µ
F
Frequency counter
56.85 – 57.35 MHz
L2 (Side A)
FM 2nd OSC
adjustment
FM 2nd OSC
adjustment
L4
FM VCO
adjustment
FM VCO
adjustment
L6
FM frequency coverage adjustment
FM frequency coverage adjustment
CT2
FM frequency
coverage adjustment
FM frequency
coverage adjustment
CT1
FM tracking
adjustment
FM tracking
adjustment
L1
FM tracking
adjustment
FM tracking
adjustment
CV1
1
30
15
16
TP
(GND)
(GND)
TP (GND)
TP9
10
1
6
5
TP6
TP10
IC3
IC1
TP8
1
2
6
8
FM/TV
RF AMP
FM/TV
MIX
FM/TV
1ST LOCAL
OSC
AFC
AM
RF AMP
OVER LOAD
AGC
MIX
1
MIX
2
PSN
1
PSN
2
AGC
AF AMP
LPF
DETUNE
DET
FM
LPF
AM
BPF
LOCAL
OSC
1/2
COUNTER
FM/TV
SELECT
FM
DISCRI
FM
LIMITTER
AMP
AM IF AMP
(FM TUN IND)
AM
DET
AGC
TUNING
IND
VCO
MUTE
SEP
CONTROL
ST.
DECORDER
INPUT
BUFF
VCO
LEVEL
CONTROL
BUFF
AMP
DC
AMP
PD
SYNC
DET
R CH
AMP
L CH
AMP
AMP
LOAD
SELECT
1/2
COUNTER
FM/AM
SELECT
M/ST.SW
ST.IND
FM/TV
30 29
25
24 23
26
28
27
22
20
3 4 5
7
9
10
11
12
13 14
15
16
17
18
19
21
FM/AM
FM/TV
38KHz
0
π
/2
FM/TV
FM/AM
19KHz
π
/2
19KHz
0
38KHz
FM IN
TV IN
NC
FM RF
GAIN ADJ
OL AGC
2ND OSC
AM OSC
TUN IND
PLL1
PLL2
VCO OSC
VCO CONT
R OUT
L OUT
ST IND
PD2
PD1
MPX IN
DET OUT
MUTE
AGC2
NC
FM IF
NC
TV OSC
FM OSC
AGC1
AM IN
NC
POWER
SWITCH
MUTE
BIAS
AMP
AMP
1
2
3
4
5
6
7
8
9
10 MUTE
R-OUT
GND
L-OUT
VCC
PWR
R-IN
GND
L-IN
REG
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