Dual 721 - Shut-Off; Stylus Slips out of Playing Groove

Shut-off
Operation
Fig.
2L.
The
functions of
automatic set—down and
shut—off are
determined by the
position of
the
deflection lever
(139). The
deflection
lever (139) is
only moved
out of stop po—
sition during
starting by the
change lever
(174).
Initiation of
shut—off after playing
the record is
brought about by
the dog (M)
of the
motor pinion
and the
shut—off layer
(142).
The
shut—off lever
(142) is guided onto
the
dog by the
movement of the
tonearm when
playing the record
with the aid of
the shut—
off
bar (182)
proportionate to
the groove
lead. The
eccentrically—mounted dog forces
the shut—off
lever (142) back
with each re—
volution as long as the
advance of the to—
nearm only amounts
to the width of one
groove
(Fig. 24 a).
Only the run—out groove
with its increased
lead guides the
shut—off lever (142) onto
the dog at a
higher rate so that the shut—
off lever is
picked up and moved along
(Fig. 24 b). The camwheel
(144) is thus mo—
ved out of
zero position into engagement
with the motor pinion
(Fig. 18 c).
Adjustment
point:
With the
eccentric pully "S" on
segment
(230) the
shut—off point can be
varied.
Fig.
23
Shut—off
Operation
DefeM
Stylus slips out of
playing
groove
Cause
a)
b)
c
d)
e)
f)
g)
Tonearm is
not ba—
lanced
Tonearm tracking
force is too
low
Anti—skating
setting incorrect
Stylus tip warn
or chipped
Excessive bearing
friction in tone —
arm
bearing
Steel ball (136)
of shut—off bar
(182) missing
Friction of dog
of segment (230)
in guide piece
(215). (Segment
shifting when to—
nearm is in stop
position for 30 cm
records.)
MR M
142 143 182
Remedy
a)
Balance
tonearm
b) Adjust
tracking force to the
value stated
by
the
cartridge
manufacturer
Correct
anti—skating
setting
Renew
stylus
e) Check
tonearm bearings and
re—adjust if
necessary
f) Renew
steel ball
(136).
g)
Bond holding
spring p31) or check ad—
justment points "b"
Fig. 18, page
15).
17