Nakamichi 481 Service Manual - page 34
5.9. Tape Travelling Adjustment
The adjustment shall be made with a modified version of the
current type EXII C-90 as shown in Fig. 5.16 (error will be
made if a current type Tape Travelling Cassette
(DAO9
011A) should be used for this purpose).
While modifying an EXII C-90, the tape guides in the
cassette housing shall be kept protected to avoid tilt. Check
shall be made in the following procedures:
(1) An EXll C-90 Tape thus modified shall be loaded onto
the N-481.
(2) Release the back-tension (rotate the Supply Reel and
feed out some length of tape) and set the N-481 in play
mode.
(3) In this juncture, check to insure whether the tape is
free from waving or slippage from the tape guide.
(4) When the modified EXII C-90 is played back, check to
insure whether the tape is freedom from waving from
head surface or at pressure rollers.
(5) If either of waving or slippage from the tape guide
should be noted, adjustments of “5.3. Record Head and
Playback Head Tilt Adjustment”, “5.4. Head Base
Stroke Adjustment”, “5.5. Tape Guides Adjustment and
Erase Head Stroke Adjustment”, “5.6. Erase Head
Height and Tilt Adjustment”, “5.7. Playback Head and
Record Head Height Adjustment and Azimuth
Alignment”, “5.8. Record Head Stroke Adjustment”, etc.
will be required.
As a case may be, the said waving or slippage may have
been caused from defective supply Pressure Roller Ass’y or
Take-up Pressure Roller Ass’y without parallel contact with
capstans. If such are noted, the Pressure Roller Assemblies
will have to be replaced.
Further, excessively weak take-up torque or strong take-up
torque may cause defective tape travelling.
The N-481 is intended to be an adjustment-free Model,
however if the similar matters as above should be noted,
please replace the Reel Hub Ass’y to obtain appropriate
take-up torque.
5.10. Record Switch Linkage Adjustment
(1) Set the N-481 in stop mode.
(2) Loosen the screw of the Record Spring Holder, and
shift the Record Spring Holder in order to remove the
looseness of the Linkage Wire as shown in Fig. 5.17.1.
Then tighten the screws for fixing the Record Spring
Holder. (In this case, the Record Switch should be
positioned at play side. If on the record position, it will
be defective.)
(3) Set the N-481 in record and pause mode.
Check to insure that the gap between the top of the wire
and the Record Spring Holder is approx. 1 mm as
shown in Fig. 5.1 7.2.
(Check that the Record Switch is in record position.)
(4) Upon completion of the above adjustments, apply a
quantity of lock tight paint.