Dual 1216 - Anti-skating Adjustment

gen.
Anti-skating adjustment
The tendency
of a tonearm
with an offset
(angled) head to
"skate"
inward
across the record
is eliminated
in the Dual
1216 by a preci-
sion anti-skating
mechanism.
Skating
force depends
on tonearm
geometry, stylus
force and the
tip
radius of the
stylus. The
inward pull on the
tonearm
caused
by the
skating effect
gives rise not
only to an
undesireable
jum-
ping of
the tonearm when lt
is.set down
on the record,
but also to
unequal forces on
the two
opposite groove
walls, with
correspon-
ding III
effects. This can be
corrected with
proper
anti-skating
adjustment.
By
turning the
anit-skating adjustment
knob
(50)
on the chassis,
an
asymmetrical curved
washer
(249) is
turned. This
washer has
two
different curved
surfaces
corresponding,
respectively ‚to
the
red and bleck
scales on the
anti-skating dial.
The
red
scale is
for
conical (spherical-tip)
styli;
the
bleck
for
elliptical
(bi
-radial) sty-
li.
When the
knob is
turned, the
curved surfaces
push the
anti-
skating lever
(231) away
from its
rest
position so that
is applies
a
suitable
counterforce via a
spring
(233).
Skating
compensation
is set at the
factory for
conical
styli with
a tip
radius of 0.6 to
0.7 mil (.0006 -
.0007 inch),
and
for ellipti-
cal styli - with
measurements of 0.20
to 0.23 mil
by 0.79 to
0.87
mil. The
hex adjusting
nut is
tightened and
sealed.
Readjustments
should be
attempted
only with
the help of
the Dual
Skate-0-meter
and test
record L
096. This work
is best
done by an
authorized
Dual
service agency.
Symptom
Fig. 9
Anti-skating
a)
Anti-skating in „0"
b) Anti-skating
mechanism in
„1.5"on the
scale for
conical styli.
Tonearrn on
rest position
c) See
„b", tonearm
onty over turntable
Causa
Remecty
Radius for
saniere
styli
Radius • r
elliptical styli
Anti-skating 1
Skating force
Anti-skating
mechanism
Stylus skips
Tonearm sets down beside tonearm
rest
Horizontal pivot friction too high
a)
Tonearm not balanced
a) Balance tonearm according to operating instructions
b) Stylus
force too low b) Set stylus force
to cartridge manufacturer's
recommen-
ded
value
c) Stylus
worn or chipped c) Replace stylus
d)
Excenssive
friction in d) Check tonearm horizontal
pivot. Should have barely
tonearm
bearing noticeable play. Adjust vertical bearing
only with the
left bearing screw (27) and the horizontal bearing with
nut. Horizontal bearing is correctly adjusted when the
tonearm, with
anti-skating 0.5 p,swings freely from
center to rest
e) Ball (235)
missing from shut-off
e) Replace
ball
(235)
raul
f) Anti-skating wrongly
adjusted f)
Correct antiskating
setting
Arm segment
(246) incörrectly ad-
justed
Tonearm
is set too
high on tone -
arm lift.
Main lever jams against
guide
pin of lift
screw
assembly
Correct
segment
positioning: after loosening screws
(245/
247) rotate
segment
(246).
Adjustment is correct when the
tonearm
descends to
the tonearm
rest
without binding.
Stylus
should be no farther from
record surface than 1/4".
Adjust by turning screw (211).