Akai 1720 L 1720 W Service Manual

Page 2

TABLE OF CONTENTS

I SPECIFICATIONS .............................. 2
I] MEASURING METHODS ........................ 3
HI CONTROL LOCATIONS ......................... 5
IV DISMANTLING OF TAPE TRANSPORT UNIT

& AMPLIFIERS ................................. 6
V TRANSPORT MECHANISM ...................... 8
VI MECHANISM ADJUSTMENT ...................... 11
V11 AMPLIFIER ADJUSTMENT ....................... 13
VIJI MAINTENANCE PROCEDURES .................. 14
IX COMPOSITE VIEWS OF COMPONENTS ............. 15
X TROUBLE SHOOTING CHART .................... 17
XI SCHEMATIC DIAGRAM

When placing order for parts, please use Separate
PARTS LIST or PRICE LIST FOR PARTS.

Page 30

V. TRANSPORT MECHANISM

Fig, I

l. CAPSTAN DRIVE
Figure l,
(A) Mann
(8) Drive Belt (nu hem
(C) (mun
(DI Flywheel
"gape-ed rouuon of Motor (A) n mnmutled by Drive
Belt (3) to Capuun (C) . which is canceled lo a
flywheel that provides newts inertia. Th'I flywheel
Ila-imam: the med rotation and ahemho mm» rotation
minions ol' the motor
Capmn Rot-mu '
(IX: IUJtI. ll 1-H!" (l9 cm) per cc.
303 RPM) nl 3-3/4 (9.5 ml per sec.
ISLS RPM. at l-l/R" (4,75 cmwer sec.
Motot Rotation I
1.000 In LSDD RIM. u 50 Hz
3.6) to LBW RPM. 3t 60":

2. PINCH WHEEL DRIVE

The prewar: cf the pinch wheel as It pushes against
capstan. tnuspons up: between «mung capslnn and
pinch wheel u the rated speed. The proper pllcll wheel
pressure It between 1.000 to LISD grams ll the up:
speed ul 7~ l."2"(l° cm) per md

3. RECORD AND PLAYBACK MECHANISM

Turning the RECORDIPLAYIMCK LEVER (A) In
PLAY" pus-tion outset the pinch wheel to press spinal
the capstan and move the up: at Ihe med speed. Al the
II'M time. M10 (I!) maves helm Mum: flushing (C)
and the Tait-Up Reel Spin: (D) to Inn-nil Nae mow!
rotation to (D) so that line tape is moved 3m! wound on
the tahup reel. The TIke-ttp Red Spindle Bole.
mmponed of two plane when (discs) (I ma 2) with a
felt dutch between. - routed (torn below by the idler.
Tape-alluding faction I muted by the iippmg of the
fell 'Id minuins KIM William of llfl lune. "w Supply
Reel Spindle (II) has I But: Ruau (E) contact);
plat-c wheel (due) (4) I'm below Much provides
Ippmpi'ute hack tension by the flipping of the fell clutch
to the rotation of the Pulley 0) above. To prevent
incidental «aura. the luau! Safely flunon (F)
must be «peeled before the RECORDIPLAYDACK
LEVER can he unwed lo the REC" position Sdlrly
dual: (6) it depmted to operate the recording much--
nllm.

(See lime 2)