Teac A-7300RX - Page 14

8-7
PINCH
ROLLER
PRESSURE
NOTE:
Pinch
roller
pressure
is
supplied
by
the
pinch
roller
solenoid
arm
and
it
is
most
important
that
the
solenoid
plungers
be
fully
bottomed
before
taking
pressure
measurement.
—
.
Load
tape
or
block
the
shut-off
arm
in
the
“ON”
posi-
tion.
Remove
the
Pinch
Roller
Cap.
2.
Attach
a
suitable
spring
scale
to
a
screw
inserted
in
the
pinch
roller
shaft.
3.
Place
the
unit
in
the
PLAY
mode,
and
holding
the
spring
scale
as
illustrated,
slowly
draw
it
away
from
the
pinch
roller.
(Do
not
allow
the
string
to
rub
against
the
pinch
roller.)
4.
Note
the
reading
on
the
spring
scale
at
the
instant
the
pinch
roller
stops
rotating.
.
The
scale
should
indicate
2
kg
+0.2
kg
(4.4
Ibs
+0.4
Ibs)
_
If
adjustment
is
necessary,
loosen
the
3
mounting
screws
on
the
capstan
solenoid
and
position
the
solenoid
for
optimum
pressure.
screw
M312
ai Shaft
Fig. 8-8 Pressure Measurement
nw”
Decrease
2
Increas
Adjustment
™ 3 Screws
Fig. 8-9 Adjustment Location
8-8 BRAKE TORQUE
The brake torque is actuated mechanically. Pressure is set
by the Leaf spring force. While making these measurements
and adjustments, be careful not to bend the brake bands.
As brake torque will change with cleaning, brake drums and
brake shoes should be cleaned only when absolutely neces-
sary. If cleaning is required, use TEAC cleaner TZ-261B.
After cleaning, operate the brakes by depressing the play
and STOP buttons several times to completely dry out the
brakes before performing the following procedure.
NOTE: Brake adjustments are made with NO power con-
nected to the equipment.
1. Place an empty large hub reel on the left reel table, and
fasten one end of a 30” length of string to the reel
anchor.
2. Wind several turns of string counterclockwise around the
hub and attach a suitable spring scale to the free end of
the string.
. Pull on the spring scale until the reel begins rotating.
. Take a reading only when the reel is in steady motion
since the force required to overcome static friction will
produce a false, excessively high initial reading .
5. The calculated valve should be 2,300 to 2,100 g-cm (29
to 32 oz-inch).
. If adjustment is required, loosen the 2 screws shown and
position the brake for optimum torque.
7. The adjustment of the right brake is the same, with the
exception that rotations are clockwise.
(wind string CLOCKWISE around reel hub)
8. See note at the top of page 16 for explanation of torque
measurements.
pW
lox
ADJUSTMENT SCREWS
Fig. 8-10 Brake Torque Measurement and AdjL ocation
15