Dual 506 - Motor and Drive; Speed Selection; Turntable Maintenance; Drive Belt Replacement

Fig. 2
Motor and
Drive
Turntable
and
mechanism are
driven by the
motor 132
in
(Fig. 16). The
shaded-pole motor
runs
vibration-free in
radially
elastic
mounts and has
an extremely
low
magnetic
leakage.
The motor
speed is
independent
of voltage,
temperature, and
load
variations. lt can
only fluctuate
with the
mains
frequency.
Two
motor
pulleys adapt
to the mains
frequency
of 50 Hz
or
60
Hz
(see pulley
116 in
Fig.
2).:
Part
no.
234 453
pulley
for 50
Hz
Part no.
234 454
pulley
for 60
Hz.
The
driving force
is
transmitted to the
turntable by the
belt 15.
Speed Selection
To
adjust the turntable
speed to 33
1/3 or 45 rpm,
the belt is
adjusted to the
one or the
other step of
the motor
pulley 116
(see Fig. 3).
This is done by
operating
the knob 16
that will shift
the
change-over lever
into the desired
speed
Position through the
lever 101 and
the spring
lever. As long as
the platter is
turned
off,
the change-over
lever is blocked
by the bar 12
and the speed
is
only
pre-selected. As soon as the
record player is
turned on
and
the turntable 7
starts running,
the blocking bar
12 will
release
the change-over
lever. The lauer
will then shift the
belt
15 to the
one step of the
motor pulley 116 that
corresponds to
the desired speed.
Tumtable
The
turntable 7 is fixed to
the turntable
bearing tube by
lock tab
134.
To remove the
turntable, lift its
top layer through
one of
the cutouts and
rotate the turntable so
that the recess is
above
the motor pulley.
Pull the belt 15 from
the pulley 116 and
place
it onto the
turntable. Rotate the latter
further until the
cutout is
above the lock
tab 134. Slacken the screw
133. Press the holding
bar 134 outwards and remove the turntable 7.
Belt
To replace
the belt, first remove the turntable
as above described,
then
remove the belt 15. Place the nevv belt on
the pulley part of
turntable 7.
NOTE: the
ground
(mat)
side
of the belt should face the
pulley.
Install the turntable. Place
the belt onto the motor pulley 116.
To Replace the
Motor Pulley
1. Remove belt 15 from pulley 116 and remove
the turntable.
Remove the
toothed belt 109.
2. Disengage the tension spring 114 from the shield 122.
3. Unscrew the hex. nut 110. Remove the set cam
111, belt
pulley 112, and
counter bearing 113.
4. Slacken
the grub
screws 117
and slide
off the
motor pulley
116. Place the replacement pulley onto motor shaft. Remove
the taper sleeve. Pay
attention to the internal distance spring.
Position the motor pulley at proper height above the mount-
ing plane — see Fig.
3—
and uniformly tighten the grub screvvs
117. Place the
taper sleeve into the motor pulley 116.
5. Mount the counter bearing 113, the belt pulley 2 112, and
the setting cam 111, tighten with hex. nut 110. Replace ten-
sion spring 114 and toothed
belt 109. Mount the turntable 7.
Place
belt 15 onto
motor pulley 116.
6. To adjust the rated
speed: adjust the knob 16 to its mid
position. Slacken or
tighten the hex. Nut 110 to achieve the
rated
speed.
Tuning to the Pitch of
Tone Level
This tuning feature is independent of the
power and controls
both turntable speeds. For 33 1/3, the control range is max. 6%
or about 1
seminote.
113 8
12
22
-117
------116
Fig. 4
110
111
112
109
114
117
119
115
Fig. 5
r
4
113
116
117
8
12
110 -125V 1
30
sw
3