Dual 621 - Tonearm Control and Functions; Automatic Tonearm Operation Modes

Tonearm Control
Automatic movement of the tonearm is initiated by the control
cams on the inside
of the cam wheel (16) on
rotating through
360°.
The control elements for raising and lowering are the main lever
(183)
and lifting bolt
(206), for
horizontal movement the main
lever (183) with
segment
(208).
The automatic tonearm set down mechanism is designed for
30 cm and 17 cm records and is coupled to the
platter speed
changeover. The setdown points of
the tonearm are determined
by the spring pin of
segment (208)
contacting the slide bar
(141).
Limitation of the horizontal movement of the
tonearm is pro-
duced by the pin of segment contacting the stop attached to the
slide bar (189). Only
during set-down does main lever (183)
lift
the slide bar (141) and the stop attached to it which, as a result,
moves into the swivel range of the stop
pin fitted on the segment.
After completion of set down (lowering of the tonearm onto the
record) slide bar (141) is released again and returns to its neutral
position. As a result,
the slide bar
(141)
moves
out of the swivel
range of the pin,
so that unimpeded
movement of the tone arm
is possible
for playing.
Continuous
Play
Continuous Play is
switched on by turning
the rotary knob
(67)
to
"0:2". The
rotary
knob (67) turns
the switch angle
(185).
The
switch rod (189) keep
the change lever
(180) in starting
position.
After the record has been played the tonearm returns automa-
tically to the lead-in groove of the record. This procedure is re-
peated until the switch
lever (68) is
brought to the "stop" posi-
tion or the
rotary knob (67) to position "1".
Adjustment Point
Pull meins
plug.
Remove platter (4). Bring
rotary knob (67) to
position "03". Turn cam wheel to central position. The change
lever (180) turns the guide lever (U) and the top of the guide
lever must at least be brought to the cam range. Adjust by
bending the switch rod
(189).
Start
Switching
the switch lever (68) into the
"starr position initi-
ates the following sequence:
a) The start lever (219) rotates
the switch lever (180) which is
pivoted about the notched stud. At the same time, the
switch
arm (41) is moved the motor
(149), via the
power switch.
(116), and the platter starts turning.
b) Operating the switch lever (68)
also releases the start slide
(38) which is drawn toward the cam
by means of the tension
spring (156). By that the shut-off lever engage with the drive
pinion and
the cam turns.
Manual
start
The latch (215) which is connected to the
switch arm
(411 en-
gages in
the four-sided plate when the tonearm is moved manu-
ally. The switch arm connects the mains supply to the
motor
(1491 via the power switch (116) and the platter rotates.
When the run-out groove of the record is reached, the
tonearm is
lifted and returned, the
motor is switched off automatically. If
the tonearm is lifted off the record before the run-out, and re-
turned by hand to the pilier, then the bolt on the segment (208)
engages the latch (215) so
that the switch arm is returned to its
starting position. This switches off the mains supply.
Fig.
13
Fig. 14
67 185
189
141
38
68 219
193
166
135
10