Onkyo PT 33 Service Manual

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SERIAL NO. 3137

ONKYOQ SERVICE MANUAL

QUARTZ SYNTHESIZED
FM STEREO / AM TUNER

MODEL PT-33

TABLE OF CONTENTS

Item Page
Specifications 2
Precautions 3
Exploded view 4
Parts list 5
Alignment procedures 6
Block diagram 8
Block diagram of IC 9
PC board-parts list 1 1
Printed circuit board View
from component side 13
Schematic diagram (120V model) 15
Schematic diagram (220V model) 17
Schematic diagram (120/220V model) 19
Packing view 2 l

ONKYOG
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ALIGNMENT PROCEDURES

INSTRUMENTS REQUIRED GENERAL ALILGNMENT CONDITION
. Stereo Modulator Standard modulation is 1 kHz 100% (FM MONO), pilot
. PM Signal Generator with Frequency Counter 9% sub and main 91% (FM STEREO).

. Frequency Counter Standard Modulation is 400 H21 30% (AM).
. Digital DC Voltmeter

DC Voltmeter
Distortion Analyzer
. AC Voltmeter
Oscilloscope

pagy-Awn...

1. Front end adjustment

TP6 Dista]
I

From DC

end

voltmeter

Ground

Step Set to dial 1 Adjust IOutput indicatorIAdjust for

120V model
l 600 kHz Digital 1.7V
L152 DC
voltmeter
2 1400 kHz TC152 614V

3 Repeat steps 1 and 2 as necessary

Other models
603 kHz L152 Digital 1.7V
DC
2 1404 kHz Ta 52 voltmeter 6'4V
3 Repeat steps 1 and 2 as necessary
Remark : Usually not necessary to adjust.
3. AM RF adjustment
2. AM IF adjustment 5°C! Output
1. Set the dial to quiet point. AC voltmeter
AM 55" PT33 fl or
v generator AM + oscilloscope
AM Mon'to 100p
SWEEP out ( l I
Generator TCl 51 PT33 P scope an enna
L______H_l
AM Signal Dial to set Adjust Adjust for
generator
1
Set signal Adjust Adjust for 503}; Maximum
400Hz. 30% 603k1-{z L151
mod.
The output of monitor 2 1404kI-I
sco becomes maximum 2
450 kHz X151 Syafiem'ca] response 4001-11. 30% 1404kHz TC151 Maximum
mod.
3. Repeat steps I and 2 as necessary
Remark : Usually not necessary to adjust. NOTE : ( ) : 220 V model

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