Dual 1211 Service Manual

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1
Muting switch
To prevent the
noises of the
change
cycle from being sent
through the
audio
system, the
apparatus is fit—
ted
with a
short—circuiting
(muting)
switch (155). The
switch
springs
for
both
channels are
actuated by
the main cam
(242). In
the tonearm
rest
position,
the muting
switch is opened.
Record drop
Insert the appropriate
spindle —
AW 3 for standard records (7 mm
center hole)
or AS 12 for
45 rpm
records (38 mm center
hole).
Record—drop is initiated by the
rotation of cam, whose cam surface
guides the
cam rocker, pushing the
change actuator stud and releasing
a record by
means of the automatic
spindle. The main cam is
designed
so that a
record can drop only
when the
tonearm is above the tone —
arm rest and thus out
of the reach
of the largest
possible records
(12"
diameter).
Shut-off
and change cycle
The dog (M) on the turntable platter gear
(PR) and the
shut—off
lever (238) actuate
both the change cycle at the end of the re—
cord as
well as the shut—off
after
the last
record in a stack is played.
At the end of a record, the tonearm moves
towards the center at an accelerated rate
due to the increased pitch of
the grooves.
This motion carries the shut—off lever
(238) towards the dog by means of the
shut—
off slide
(278). The eccentric
dog pushes
the shut—off lever (238) back at each re—
volution
as long
as the
tonearm
advance is
only one normal record groove.
The
run—out groove with its steeper pitch
moves the
shut—off lever
against
the dog
with greater
force, engaging the
shut—off
lever (238) and causing
the main cam (242)
to
be driven out of
its neutral
position
by the turntable platter gear.
Fig. 15 Record drop
193 242 155 226 224
218
212
214
Fig. 16 Actuating "change"
or
"shut—off"
PR
M
242
239
238
278
268
269
221
271
278
11

Dual 1211 Specifications

General

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