Dual CS 731 Q - Tonearm Operation and Adjustment; Anti-skating Force Adjustment; Tonearm Cue Control Operation

4.
Disengage
tension
spring
(136).
Release
securing
disc
(90)
and
remove
skating
lever
(134).
5.
Remove
hexagon
nuts
(94).
Remove
countersunk
screw
(138).
Remove
counterbearing
(135)
and
segment
(124).
6.
Retain
tonearm
(30)
and
frame
(63).
Remove
filister
head
cap
screw (88). Remove
tonearm
complete
with tonearm
bearing.
When
fitting
the
tonearm
proceed
in
reverse
order
but
ensure
that
the
threaded
pin
(62)
seats
correctly
on
ball
bearing.
Replacing spring housing
Remove tonearm (30) from bearing frame (66) as described
above.
When
installing
notice
that
the
helical
spring
engages
in
the
cut-
outs of the bearing
(71). Mount tonearm
(30) again. Set bearing
play
as
described
below
using
threaded
pin
(65)
and
lock
nut
(61).
Adjusting the tonearm bearing
First
balance
tonearm
accurately.
Both
bearings
must
have
slight,
just
perceptable
play.
The
horizontal
tonearm
bearing
is
correctly
adjusted
when
at
anti-skating
setting
0.5
and
being
touched
it
slides
in
without
resistance.
The
vertical
tonearm
bearing
is
cor-
rectly
adjusted
when
it
swings
in
after
being
touched.
The
play
of
the
horizontal
tonearm
bearing
should
be
adjusted
with
thre-
aded
pin
(62),
the
play
of
the
vertical
tonearm
bearing
with
threaded
pin (65).
Anti-skating device
Adjustment of anti-skating force is carried out by means of
turning the knurled ring on the cover. According to adjustment
the asymmetrical cam disc guides the skating lever (134) from
the tonearm pivot point. The anti-skating force is transmitted to
the segment (124) by means of tension spring (136) and to the
tonearm.
Optimum adjustment is carried out at the works for styli with a
tip radius of 15 um (conical), 5/6 x 18/22 ит (elliptical) and CD
4 cartridges.
Any alteration can only be carried out with the aid of a Dual
skate-O-meter
and
a
test
record
and
should
only
be
done
by
an
authorized Dual service station.
Cue control
By moving lever (187) forward (Y.) lift cam (188) rotates. The
slide bar (168) connected to it transmits this movement to the
lift
pin
which
then
raises
the
tonearm.
As
a
result
the
cue
control
permits set down and lift off of the tonearm at any desired point
outside the shut-off range.
The slide bar (168) is released again by moving the cue control
lever (187) to the rear (X). As a result of the action of compres-
sion spring the lift pin is returned to neutral position and thus
lowers the tonearm. Lowering of the tonearm is damped by
silicone oil in the lift tube.
The set down speed can be varied by adjusting the pretension
of compression spring (lift plate 176). According to operation of
the
adjusting
ring
(82)
in
position
"4"
the
lowering
speed
is
slower, in position "444" it is faster.
Adjustment point
The lift height can be varied by turning adjusting screw (51). The
distance between record and stylus should be approximately 5 mm.
63
|—
62
74
66—
a
69
70
65-
e
=
тз
т
72
8t
82
83
ын
485
124-
94
138
Replacement of cue control plate
Replace cue control plate as follows:
1. Fix unit on repair jig and lock tonearm. Turn unit upside
down.
2. Remove securing disc (89). Detach main lever (167) and
bearing block (166).
3. Remove securing disc (89). Remove adjusting bar (168) and
rotary bearing (170) and swivel to motor.
4. Remove both filister head cap screws (97), remove cue control
plate complete (176).
Fitment takes place in reverse order. It should, however, be noted
that the pressure piece in the cue control plate (176) engages
correctly in adjusting ring (82) (varying the lowering speed.
Fig.9
е 9
Tonearm control
Automatic movement of the tonearm is indicated by the control
cams
on
the
inside
of
the
cam
wheel
(16)
on
rotating
through
3600.
The
control
elements
for
raising
and
lowering
are
the
control
lever
(167)
and
the
lift
pin,
for
horizontal
movement
of
the
tonearm
control
lever (167) with segment
(124).