Dual 502 - Tonearm Adjustment and Operation; Bearing Play Adjustment; Anti-Skating Force Setting; Cue Control Functionality

Adjustment of
tonearm bearings
Anti-Skating
Device
First balance tonearm exactly. Both bearings
must
haue
slight, just perceptible play. The
horizontal tonearm
bearing is correctly ad-
justed when at
anti-skating settings "0.5"
and being touched lt
slides in without re-
sistance. The vertical tonearm bearing is
correctly
adjusted when lt swings in fter
being touched. The play of the
horizontal
tonearm bearing should
be adjusted with
threaded pin (44), the
play of the vertical
tonearm bearing
with threaded pin (60).
Fig.
7
Anti-Skating
The
anti-skating force is set by turning
the
pointer disk (69).
According to the
setting the asymmetrical
cam plate (73) mo-
ves the skating lever (191) from its center
of rotation. The anti-skating force is
transmitted by the tension spring (185) to
the segment (184) and, finally, to the to-
nearm
(49).
Optimum adjustment is carried out by the
manufacturer for styli with a tip radius of
15 gm
(conical) and 5/6 x
18/22 µm
(ellip-
tical) as well as for CD 4
pick -up cartrid-
ges. Alterations can be made only
with the
aid of the Dual Skate -O -Meter and the test
record and should only be done by an
autho-
rized Dual Service
Station.
Recheck
as follows:
Balance tonearm (49). Set pointer disk to
0 (69). Now the tonearm should remain in
any position
of its moving range. The ho-
le of the skating
lever (191) should align
the center line of the tonearm.
This is ad-
justable with the eccentric pulley accessi-
ble through the hole
in the mounting plata
(38) between the pointer disk (69) and the
bearing base (47) (Fig. 13).
The set
knurled
ring (69)
to "0.5".
Now the
tonearm
should return
from the
center of
the platter to
its rest (77).
Cue Control
The
cue
control permits
gentle
set-down of
the
tonearm at any
desired
point (outside
the
shut-off
range) on the
record.
By moving
the lever
(194) (moving
forwards)
lift cam
(197)
rotates. The slide
bar (176)
connected to lt
transmits this movement
to
the lift
pin
which
then raises the tonearm.
After Moving the
tonearm into the
desired
position on the
record. The lever is
releas-
Fig. 8
Cue
Control
ed by gently
moving to the rear.
As a re-
sult, slide bar (176) is
released and the
tonearm lowers slowly.
Lowering of the to-
nearm is damped by
silicone oil in the lift
pin.
The height of the
stylus above the record
can be
varied by
turning adjusting
bush
(179). The distance
is reduced by
turning
clockwise. The distance
between record and
stylus can
be increased by
turning counter-
clockwise. The
distance presst by
the fac-
tory
is approx. 8
mm.
3
,
4 U
geeree>
194
197
176
193 177
175
6
179 183