Dual 1211 Service Manual

Fig. 2 Motor suspension and turntable drive
102 7 6
106 135 108
107
Motor
and drive
MN
r&ram u
_
221
176/131
148
136/144
133/140 114/189
The turntable platter and the mechanism are
driven by
either a 4 —pole (131)
or a 2 —pole
(176) induction motor. Both motors have a
balanced armature, polished bearing surfaces
and are
guaranteed
vibration—free. The
4 —pole motor has the additional advantage of
a very small
stray magnetic field.
The speed of the motors is constant over a
supply
voltage range of 10 %.
Deviations
in speed depend on, and are proportional to,
line
frequency. Adaptation of
the motor to
50
or 60 Hz power
is accomplished
by changing
the
motor pulley
(11 4 / 1 89).
2 —pole motor:
pulley
for 50 Hz
part no.
pulley for 60 Hz
part no.
4
—pole
motor:
pulley for 50 Hz
part no.
pulley
for 60 Hz
part no.
212 135
212 136
220 970
220 971
Fig.
3 Motor field
connections
(less voltage selector)
-
r ----
1 1
•
L
110/125
>
•
The motor
pulley is secured to the motor shaft
by a setscrew.
When a pulley is
replaced or ex—
changed, lt
must be set
at the
correct height
(see Figs. 5
and 6).
The
turntable platter is driven
by the idler
wheel (133/140) which is
automatically disen—
gaged from the motor
pulley when the unit is
shut—off, in order to
protect its driving sur—
face.
Turntable speeds of 33 1/3,
45, 78 rpm are se—
lected by raising
or lowering the
idler wheel
(133/140) to
the appropriate step on
the motor
pulley.
When the selector lever (6)
is moved, the selec—
tor
segment (105)
rotates. This causes the
lever
(107)
fitted in the slot of
the selector
seg—
ment to move in a
vertical
direction. The idler
wheel (13 3
/ 1 40) mounted on
the swinging arm
(136/144) is lifted
off the motor
pulley and
set down
again on the motor
pulley step for the
adjacent
speed.
Fig. 4
Motor field
connections
(with voltage
selector)
17571 ,
220/240V
4

Dual 1211 Specifications

General

Weight	6.5 kg
Speeds	33, 45 RPM
Platter	Aluminum
Wow and Flutter	<0.15%
Drive Type	Idler Wheel Drive