Dual 521 Service Manual

Stop Circuit
When
you adjust the
lever
(48)
to
STOP, the srart
angle (1911 is
released and pulled
towards the cam
wheel by tension spring
(1921.
As a result, the
shut-off lever is
brought within the range
of the dog
(M) on the pinion (PR)
of the turntable and the
cam
wheel (161) becomes
driven. The reversing
lever remains in
its stop position.
Adjustments
Tone Arm Set -down Point
Slightly pprey up the
nameplate "Dual" at its lower left
corner
and swivel lt outwards
(Fig. 19). The now accessible
opening will
show one of the adjusting screws.
Set -down Point for 30 -cm Records
Adjust the
speed selector 1181 to
the "45" position and
correct
adjustment with a screwdriver.
If the stylus sets down too far
on
the record inside,
rotate the adjusting screw
clockwise. If the stylus
is lowered outside the 30
-cm record, rotate the screw
counter-
clockwise.
Set -down Point for 17 -cm
Records
Adjust the
speed selector (181 to the "33"
position and rotate
the screw as above described for adjustment.
Shut-off Point
In the shutting-off range for records
116 — 122 mm in diameter,
the
excenter (S) on segment
(200)
(Fig.
18) can be used to vary
the shut-off point.
Fig.
18
Defect
Turntable
does not start.
Cause
a) Belt is
not in
place.
b)
Motor is not
powered.
c) Motor
pul ley has
come
loose.
Tu rntable
speed unsatisfac- a)
Motor
pulley does
not
tory.
comply with
mains
frequency.
b)
Belt sl ips on
motor pul ley or
turntable.
c) Excessive
bearing
friction.
Fig. 19
Tone Arm Lift
Height
This height for the auto
mode can be adjusted with
the aid of
the setting sleeve
(156). Pull the mains
plug. Disengage the tone
arm. Rotate the cam
wheel (161) out of its zero
position until
the tone arm has
reached its greatest lift height.
The height
above the tone arm
support stop should
be about
7 mm as shown in Fig.
20. If necessary, rotate
the setting sleeve
(156) clockwise or
anticlockwise as required.
Fig.
20
Repair
a)
Mount the belt.
b) Check switch base and mains
plug.
c) Tighten
it.
a) Exchange it.
b)
Clean all contacting
surfaces of belt and
pulleys, if necessary
replace the belt.
cl Clean and relubricate
the bearings.
9

Dual 521 Specifications

General

Drive System	Belt drive
Speeds	33 1/3 and 45 RPM
Weight	5.5 kg
Anti-Skate	Yes
Stylus	Elliptical
Output	Depends on cartridge