Dual 1216 - Pitch Control; Tonearm and Tonearm Bearing

Pitch Control
For turntable speeds 33 1/3,45 and 78 rpm,
the unit incorporates
a voltage-indenpendent pitch
control, wh ich permits a turntable
speed variation of up to
6%
(approximately one sem
itone).
When the pitch control knob (9) is turned, the switch segment
(112)
and the switch lever
(105)
attached to it
are moved
up or
down. This vertical
displacement changes the position of
the idler
wheel
on whatever step of the motor pulley it has been placed
on
(by the speed selector), and, due
to the tapered shape of the pul-
ley, effects approximately ± 3 % variation in speed.
Symptom
Causa
Fig. 5
Motor pulley Position
Remedy
Turntable does not
run when unit is
plugged in and start
switch operated
Turntable does not come up
to speed
Rumble in reproduction
Correct nominal speed obtained only
at extreme settings of pitch control
Symptom
Tonearm head is
not parallel to
turn-
table
platter
Cause
Orientation of
tonearm head on
tonearm tube has
altered
because
of jolting in
transport (shipping)
•
a)
Current path
to motor
interrupted
b)
Idler wheel (108)
not in
contact with
platter
c) Motor pulley
loose
a) Motor pulley
is not correct
for local
line frequency
b)
Slippage between
idler wheel
(108) and motor pulley (120)
or
platter
c)
Excessive friction
in motor,
drive wheel or platter
bearings
Worn
idler wheel
Idler wheel does
not contact
motor
pulley correctly
Remedy
Remove turntable platter
with the help of a
screwdriver
inserted through the
hole in the
chassis placed there
for
the purpose. Loosen screw on
tonearm
head.
After
cor-
recting
the
tonearm head,
tighten
screw.
(Fig. 6)
•
a) Check connection at switch plate and voltage selector
b) Check switch lever
assembly
(105)
c)
Tighten motor pulley
a)
Change motor pulley
b)
Clean friction
surfaces of
idler wheel, motor pulley
and
turntable platter. If necessary, replace drive wheel. Once
the drive surface of the platter has been cleaned, do not
touch it with your fingers
c)
Clean and oil bearings
Replace idler wheel (108) and clean platter drive surface and
motor
pulley with greaseless solvent. Once surface are cleaned
do not touch them with your fingers
Loosen setscrew
(122) and
by means of setscrew
(119) adjust
the motor pulley on the motor shaft so that when the fine
speed adjustment knob is in the center of its range, the idler
wheel is positioned in the center of the appropriate motor
pulley step. (Fig. 6). When adjustment is completed, tighten
setscrew
(122).
Fig. 6