Dual 1229 Q - Anti-Skating Device and Adjustment; Tonearm Bearing Reassembly Procedures

Fig. 11
Tonearm
bearing
assembly
viewed
from
underneath
273 270 184 210
Fiq. 12 Anti—skating force
Cam
wheel
a) Anti-skating in "0"
Skating
lever
Shut-off
slide
Radius
for
conical
styli
b)
Anti-skating
mechanism
in "1,5" on the
scale
for
conical styli.
Tonearm on rest
position.
Radius for
elliptical styli
c) See "b",
tonearm
only over turn-table.
Anti-skating
force
Skating force
Tension
spring
Segment
58
74
77
233
258
241
201
267
Shield
Tension spring
Anti-skating
mechanism
To replace
the tonearm bearing
assembly,
hold it with
a suitable tool
(such am a
pair of
flat—nose pliers)
and loosen hex
nut (71)
with an
open—end wrench. Be
sure
to
secure the bearing
socket with a 5 mm
rod to
prevent its
being pinched
together.
Reverse the
procedure to reassemble
the to—
nearm and
bearing. The unit must be
right—
side—up. After
assembly, immediately
place
the
mode selector at "single".
This prevents
the tonearm from
falling out when the
unit
is turned upside
down again. Do not omit
spring
(78).
Install segment (201) and lift
plate (203).
Tighten the positioning
sleeve (200) on the
lift tube. Insert lock washer in
recess on
lifting pin and mount the
guide again. Be—
fore tightening hex
nut (236), rotate outer
bearing frame (58) counter—clockwise until
you feel
slight resistance. This puts the
forward
edge of the outer bearing
frame
approximately at
the center line of the in—
ner tonearm bearing screw,
and represents
the correct tonearm position.
After reinstalling the
protective plate,
ensure that the segment (201) moves freely
and without rubbing in its guide (232) and
is not hindered in its
movement by the to—
the tonearm wires. Adjust tonearm height
with positioning
sleeve (200) and locating
screw (79) in "multi" position at the
mode
selector. Correct position with main lever
pressed up
is approx. 0.5 mm play remaining
measured at tonearm head, see Fig. 13.
Anti-Skating
Device
The tendency of a
tonearm with an offset
(angled)
head to "skate" inward
across the
record
is eliminated in the
Dual 1229 Q by
a
precision 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 ska—
ting effect
gives rise not only to an
un—
desirable
jumping of the tonearm
when set
down on the
record, but also to
unequal forces
on the
two opposite
groove walls,
with cor—
responding iii
effects. This can be
correc—
ted by
proper
anti—skating
adjustment am pro—
vided on a
high —grade
HiFi record
player.
By turning
the anti—skating
adjustment knob
(84) on the
chaasis, an
asymmetrical
curved
surfaces
corresponding
to the red and
whi—
te scales on the antiskating dial. The red
sdale is for conical (spherical tip styli,
the white for elliptical (bi —radial) styli
and for CD -4
quadrophonic cartridges. When
the knob is turned, the curved surfaces push
the anti—skating lever
(267) away from its
rest position
so that it applies a suitable
counter—force via a
spring (265).Skating
compensation is set at the factory for
conical styli with a tip radius of 15 +
2 µm,
and
for
elliptical
styli
with mea:
surements of 5/6
x 18/22 µm. The adjust—
ing hex nut (259) 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 should be done by
an authorized Dual
service agency.
8