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HITACHI HT-21/G2
English
ADJUSTMENTS
1. Adjustment of the auto-return position
Play the auto-return adjusting groove on side A of the
Hitachi
test record HT-SE (Stock No. 2561131) and
adjust the return adjusting cam so that the tone arm
returns automatically in the range of No. 5 — 9.
The auto-return
position can be adjusted using a ©
screwdriver.
i
Auto
return
adjustment
Stylus
height
adjusting
screw
Fig. 4
. Adjustment of the stylus height
Place a record disc on the platter, and adjust the height
by loosening -the stylus height adjusting screw so that
the height from the record disc to the stylus tip is
6 — 9mm when the arm lifter is set to UP.
Check that the stylus is more
than 4 mm above the
record during Auto-Retumn. (Fig. 4, 5)
Arm guide: UP position
Fig. 5
3. Stylus tip position adjustment
(Overhang adjustment)
When the cartridge is attached or replaced, adjust the
stylus tip position as shown in the Fig. 6.
MT-35
Cartridge fixing screw
Head shell
Cartridge
Stylus tip ———e
~—
ae
(Actual size)
MT-15
Cartridge fixing screw
Head shell
Cartridge
Stylus tip ——e
k—
30mm
(Actual size)
Fig. 6
4. Speed adjustment
Adjust the speed adjusting semifixed resistors (RO3, 04)
in the following way.
(1) Set the speed to 33 rpm, and turn R 03 gradually
until the stripes of the strobo are stationary.
(2) Next, set the speed to 45 rpm, and adjust R 04 in
the same manner.
Check that exposed parts are acceptably insulated
from the supply circuit before returning
the instru-
ment
repaired to the customer.
@ Checking method
Remove the torn arm to the inside of the Platter
(Power switch is set to ON.).
Next,
measure the resistance value between the
both poles of attachement cup (Power supply plug)
and the exposed parts (Parts such as Ground wire
terminal, Platter,
Tonearm,etc. where the customer is
easy to touch.) and check that the resistance value
is 500kohms or more.
INSTRUMENT
(Exposed part)
Insulation tester
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