Bang & Olufsen BEOCENTER 2000, Руководство по обслуживанию

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Bang&Oiufsen
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DESCRIPTION
Power supply
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FM-AM
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8-1
Due
to
the fact that the circuits of the Beocenter 2000 are rather conventional,
they
will be
described by means of block diagrams.
08
Pow..,. supply
601
602
BD3
, 42 V
8TR1
a·�·
•
l�V
1
- l�V
- 26V
806
•
19V
BTR4
BTR3
•
12Va
607
8TR6
8TR5
•
12Vb
808
The power supply of the Beocenter 2000 has
8
output voltages as shown in
above block diagram.
These
8
voltages are used in the following circuits:
+42V
+26V
+14V
-14 V
-26V
+19V
+ 1
2 V a
+12Vb
Microphone amplifier
FM turting
Tone control
RlAA amplifier
Output amplifier
Headphone amplifier
Headphone amplifier
Output amplifier
Record player ON/OFF
RF circuit
Stereo decoder
Tape recorder AF circuit
Tape recorder motor control
Record player motor control
Muting circuit
Rec. indicator
LF R o g h l
LF Lell
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e
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Bang&Oiufsen 7-2
Pick-up height
Pick-up ann balance
Pick-up ann parallelism
Antiskating
Put a record on the turntable.
Position the pick-up arm above a run-off groove.
Adjust screw A until the distance from the stylus to the record is 5 mms.
This adjustment must be made with a counterbalance weight mounted.
==O=H
Turn the counter-balance weight until pick-up
arm
is in balance.
Hold the counter-balance weight in this position and zero the dial B.
The counter-balance weight A is turned clockwise until the dial B shows the
stylus pressure required (for MMC 20" it Is
1.
5 grams) .
Loosen the screw B and turn the pick-up arm until the A and B clearances are
equal and the straight section of the pick-up is parallel to the topside of the
record.
8
Put the test record 3621045 on the turntable.
Set stylus pressure to 1. 5 grams with MMC 20S.
Play cut
1.
Connect an oscilloscope to the RH and LH channels.
Push stud B in either direction of the arrow A until there is an equal distortion
in both channels (for LH channel distortion, slacken spring C, tighten for RH
channel distortion).