Dual 1216 - Tonearm Replacement Procedure

Tonearm
and tonearm bearing
The
tonearm of the Dual 1216
is counterbalanced and
pivots
vertically and
horizontal ly on precision ball
bearings. This ap-
roach
gives highly favorable
tracking characteristics.
The tone -
arm head is
removable. To aid in replacing or
adjusting the
tonearm head, a hole is
provided in the turntable
base to faci-
litate
mounting the tonearm
head without first
removing the
tonearm.
Before setting the
correct stylus force for the
car-
tridge that has
been installed, the tonearm
should be balan-
ced with the stylus-force
setting at zero.
Fig. 7 Tonearm
bearing assembly
39
28
27
30
31
48
104
170
245 246
49
Fig. 8 Tonearm bearing assembly
(under view)
45
39
37
43
237
232
246
249
192 233 204
250
231
40
45
43
46
47
lt is
recommended that the balancing
should be done right next
to the
tonearm rest.
The counterweight is so designed
that is can balance cartridges with
weights from 1 to 8 grams.
For shock absorption . (the
absorption of short, rapid jolts) the counter-
weight is elastically mounted on the
tonearm and bracked to prevent
unintendet rotation. The
tonearm
head is
designed to accept all
car-
tridges
with
internationally standard 1/2 inch mounting centers and
with a weight not exeeding 1-8
grams. Stylus force is set ny turning
a calibrated spring housing (40),
thus tensioning or slackening the spiral
spring
lt contains. The scale is calibrated over a range of 0 to 5.5 grams,
allowing an exact setting of stylus within that range in 0.5 gram steps.
To replace
the tonearm with its
bearing assembly,
the following proce-
dure
is recommended:
1. Secure the
unit in the repair jig,
set the stylus force
to zero and lock
the
tonearm in place.
2. Turn the unit
tipside down and
unsolder the
tonearm leads.
3. Remove main
lever (204) and linking
lever (192).
4.
Connect the springs
and screw on the
shield.
5.
Unfasten the
c-washer and remove
skating lever.
6.
After loosening the
c-washer
(254) and friction washer
(253)
separate
shutoff
slide
(234)
four segment
7.
Loosen cylinder screw
(245/247) and remove
segment.
8. Hold
the main lever
bracket and unscrew the
hex nut ( 4 a
9.
Pull out the ball bearing
with balls (5 pieces)
10. Set the
unit on an upright
position and take
out the tonearm
together
with the
main lever bracket.
Screw
on
the hex nut until you feel
a swall resistance.
After
screwing lt on place, there
must be a noticeable play. After scre-
wing
on the cylinder screw, test the tonearm by setting
lt
over the
tonearm rest.
The tonearm is correctly set when the
tonearm can be lowered onto
the rest without
binding.
When reinstalling the protective cover (237), be sure that the segment
(246) can move without hindrance though the tonearm leads.
To remove the tonearm from its bearing frame, unsolder the tonearm
leads, then set the stylus-force adjustment to
zero. Unscrew locknut
(28)
with setscrew (27) and bearing screw
(45)
(iefthand
thread).
Carefully lift the tonearm free from the bearing frame.
6