JBL JSR 400 Service Manual ▷ View online
TUNER ALIGNMENT
Test Equipment Required
1) AM/FM Signal Generator
2) Digital Multimeter
FM Tuner Section
Connect the FM signal generator (FM SG) to the FM antenna a 300
W
terminal through a 300
W
dummy antenna.
Set the receiver to the FM band.
1) Tune the FM SG to the receiver.
2) Connect the FM Multiplex stereo signal generator to the FM SG external modulation terminal.
3) Set the modulation to main 1 kHz/L+R/67.5 kHz deviation, pilot 19 kHz/6 kHz deviation.
STEP
FM SG
1 kHz 75 kHz deviation
Tuner Frequency
Display
Adjustment Point
Adjustment Procedure
Frequency
Level
1
No Signal
87.5 MHz
Confirm that DC 1.8 ±0.5V between VT Terminal
and Ground
2
No Signal
108 MHz
Confirm that DC 8.0V ±0.5V between VT
Terminal and Ground
3
98 MHz
66 dBu
98 MHz
FM DET COIL
- T4 -
Connect the Digital Volt Meter to WA2 Adjust T4
so that adjustment value is less than ±30mV
4
98 MHz
22 dBu
98 MHz
S.F.R. 10K
VR302
Adjust until you turn on the “TUNED” segment in
V.F.D.
5
98 MHz
66 dBu
98 MHz
S.F.R. 220K
VR401
Adjust so that the left (or right) channel output
becomes minimum when only the right (or left)
channel of the stereo modulator is modulated.
AM Tuner Section
1) Connect the furnished AM Loop antenna between terminals AM ANTENNA and GND.
2) Connect the AM signal generator (AM SG) tot he AM antenna terminal.
3) Tune the AM SG to the receiver.
STEP
AM SG
400Hz 30% Mod.
Tuner Frequency
Display
Adjustment Point
Adjustment Procedure
Frequency
Level
1
No Signal
520 kHz
AM OSC COIL
T6
Adjust until DC 1.2V ±0.03V between VT jumper
and ground is attained (J37)
2
No Signal
1720 kHz
CERAMIC TRIMMER
CT2
Adjust until DC 9.0V ±0.5V between VT jumper
and ground is attained (J37)
3
Repeat the step 1 and 2 until both specification are correct.
4
600 kHz
22 dBu
600 kHz
AM ANT COIL T1
Adjust until you turn on the “TUNED” segment in
V.F.D.
5
1500 kHz
66 dBu
1500 kHz
CERAMIC TRIMMER
CT1
Adjust until maximum sensitivity is attained
6
Repeat the steps 4 and 5 until maximum sensitivity is attained.
7
1000 kHz
100dBu
v/m
1000 kHz
AM IFT COIL
T2
Adjust until maximum sensitivity is attained
8
1000 kHz
83dBu
v/m
1000 kHz
S.F.R. 10K
VR301
Adjust until turn on “TUNED” segment in VFD
2 9
Dolby Pro-Logic
Ò
A/V Receiver
JSR-400
3 0
Dolby Pro-Logic
Ò
A/V Receiver
JSR-400
T1
T6
T2
T4
F202
CT2
J37
CT1
ANT1
PACK1
IC2
IC3
IC4
VR302
VR301
VR401
WA
2
TUNER PCB
ALIGNMENT
LOCATIONS
3 1
Dolby Pro-Logic
Ò
A/V Receiver
JSR-400
JSR-400 MAIN PCB
JSR400
MAIN PCB
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JSR-400 PAGE 31 - 1 of 2
JSR-400 PAGE 31 - 2 of 2
3 2
Dolby Pro-Logic
Ò
A/V Receiver
JSR400
JSR-400 CONTROL PCB
JSR400 Control PCB
IC1
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JSR-400 PAGE 32 - 1 of 2
JSR-400 PAGE 32 - 2 of 2
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