Akai GX-77 Service Manual

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TR2s8
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at ov re
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to IC1@@)
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to STOP KEY
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IK34A
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R36
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TIOIOD5230
DETECTOR PCB
TIOIOD5240
Sc cr
Fig. 23
TRI7 COLLECTOR
O!13: CATHODE
TRI6 BASE
TRIS COLLECTOR
2)
Auto
Stop
Circuit
(Refer
to
Figs.
23,
24)
same
as
in
FWD
and
REV,
the
auto-stop
works
Photo TR (TR2) is repeating ON/OFF when the
tapeis running.
The pulse of TR15 collector is added to IC1 @
and TR20 base.
TR2
collector
is
connected
with
TR28
collector,
and
while
TR28
base
is
“H”,
TR21
is
“OFF”,
ie.,n0
auto-stop.
In
FWD
and
REV,
the
auto-stop
funcions
when
the
tape
is
winder
up
by
the
takeup
reel,
tension
arm
(right)
is
lowered,
and
micio
SW
SW904
is
shut
off.
In
FF
and
REW,
about 4 seconds after the micro SW SW904 is shut
off and the tape pulse is gone.
In FWD, REV and FF, REW, the positions of
TR28 and D12 are as follows.
FWD, REV > FF,REW
TR28 : ON (Always) ON ~ OFF
D12_ : OFF (Always) ON about 4 seconds
after tape pulse dis-
appears
er
en
preneryeneneeaese

Akai GX-77 Specifications

General

Track System	4-track, 2-channel stereo
Tape Speed	3 3/4 ips, 7 1/2 ips
Wow and Flutter	0.03% (19 cm/s)
Heads	3
Motors	3
Dimensions	440 x 244 x 358mm
Inputs	Line input (RCA)
Outputs	Line, Headphones