Adjustment Of Tape Transport Unit; Adjustment Of Pinch Wheel; Adjustment Of Take-Up Idler Wheel; Adjustment Of Rewind Idler Wheel - Akai 1700 Service Manual

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U ADJUSTMENT OF TAPE TRANSPORT UNIT
1. ADJUSTMENT OF PINCII WIIEEL
It is imporlant that the piich wheel shaft i5 kept nr
c o m p l c t e a l i g n m e n t w i t h t h e c a p s t a n s h a f t . A p r o p e r p i n c h
wheel pressur€ is bctween 1.000 and I,150 grahs whcn the
unit is ope.ated at the tapc spccd of7-t6 ips. Any devia'
tion from this specificalion will result in wow and flutter.
C h e c k I ' i n . h w h e e l p r e " s u , . b v r . 1 - . r i n g ' c a l e a t . d . i f
r , e c e s a r y . a d j u " r r h e p i n , h w h p F l l o a d 5 t . i n B .
2, ADJUSTMENT OF TAKE.UP IDLER WHEEL
The take-up ;dlm wheel must be kcpt in complete align-
ment ltith thc takc-up reel shaft. Whcn the unit is set in
fast forward condition, thc idler whe€l will contact to the
upper knu.led wheel of the takc-up reel shaft assembly.
and it will contact to thc lower kn urled whccl du.ing record
o r p l a y m o d c . A d j u s t i d l e r w h c c l l o a d s p r ; n g s o i h a t l h c
idler wheel pressurc is kept between 50 and 80 grams. The
; d l e r q h . . l r a p i d l v w e a r . : f I h f p r e * u , . b P x , . s s i \ c .
The slippage occurs if thc prcssu.e is smallef thaD the
3. ADJUSTMENT OF REWIND IDLER WSEEL
The .c\rind idler whccl must be kcpt in complete align-
mcnt with thc rewi.d reel shaft. The amount of pressurc
to the k,,urlcd motor bushing should be maintained about
50 gfams during rewidd ope.ation. Adjust both thc idler
load spriog aDd rewind roller.
4. ADJUSTMENT OF INTERMEDIATE WHEDL
Thc intcrnediatc wheel is located between the rewind
idler whccl and thc rubbe. ring vhich is uscd on the uppe.
part of the supply reel shaft assembly. When the unit is
sct in rewind mode, it will contact to thcsc parts sihul-
taneously deliverins torque of motor. An adequate pres-
s u . c i s 5 0 g r a m s . A d j u s t t h c l o a d s p . ; n g o f t h c i n r e r m e d ; a t e
wheel if the pressure is not sufrc;ent.
5. ADJUSTMENT OF TAKE-UP REEL SIIAI'T
ASSEMBLY
A felt clutch mat.rial is attachcd to the bottom sid€ ol
the reel table basc plat€ so that reco.ding tapc w;ll not bc
stretched during lhst forwafding operation due to excesivc
tension. To check the amoudt of friction of this part, plac€
a S ' i n c h r e e l w i t h f e c o r d i n s t a p e w o u n d b y 6 0 m / m i n
diameter, and gently pull the cnd of tapc upwarcl using a
spring scale. Adjust the conical sp.ing so that thc amount
of tension at this part will bc kept between 400 to 500
grams.
Anoth€r felt clutch matoial ;s attached to the
takc-up drive wheel. It is to pfovide proper slipping opc-
ration du.ing record or play modc.
The procedu.e for
checkins friction of this part ; same as the foregoing, and
between 120 and 200 grams of frictioD will provide the
best result. Adjust the star-shapcd spring jnst under the
takc-up dr;ve whcel. lvhen the unit is set in rewind
mode, the amou.t of f.iction of this part will greatly be
reduced and \viil become I0 to 20 grams. Check to scc
rvhether this is satisfactory ;f iot, readjust the star-shaped
spring fo. Bfakc, and spring rctainef washed accordingly.
l s c c f i s u r e l l ( a l a t l e f o
6. ADJUSTMENT OF SUPPLY REEL SIIAFT
ASSDMBLY
A felt clutch matoial is uscd between the love. side of
thc reel table base plate and the .ewind rubbcr ring to
protect reco.ding tape from an excesive tension \th;le re-
winding operation. To check thc amount offriction of this
pa.t, place onto thc supply reel table a 5-inch rcel with
rcco.ding tape wound by 60m/m in diameter and gently
pulL thc cnd of tape upward by a spring scale. Adjust
thc conical sp.ing so that thc amount of tens;on ;s kept
bctwecn 400and500grams. Anothc. fclt clutch is attached
to thc re\v;nd drive wheel to provide proper sl;pping
ope.atioD cluring reco.d or play mod.. The procedure
for checkn)g friction of this part is same as the foregoing,
and betwe€n 80 and 120 s.ams of friction will give the
best result. Whcn the unit js set ;n fasi forward modc,
the amount of f.;ction will greatly be reduced and will
become l0 to 20 grans.
Check to sce whether this is proper, if not, rcadjust coil
spring and spring r€tainer washc..
{See figure I I (b) at left)
7. ADJUSTMENT OF TAPE HEAD
A vertical azimuth alignment of tape head is the only
adjustment that can be made at the field of service. To
align tape head, play 8,000 cycles recordcd on an AmP€x
standard alignment tape. Rotate th€ azimuth al;gnment
sc.ew until a maximum playback level through the small
hole which is positioned on the shield cover of the tape
head assembly.
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Fig. 12
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