Akai GX 280 Service Manual

Page 2

STEREO TAPE RECORDER

MODEL GX-280

ALSO APPLICABLE TO MODEL GX-280D
STEREO TAPE DECK

SECTION 1 SERVICE MANUAL ........................ 3
SECTION 2 PARTS LIST ............................. 35
SECTION 3 SCHEMATIC DIAGRAM .................... 64

Page 18

Audio
Frequency

Oscillator

Line
input

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TRZO! zscase L6
mam 25C7ll%®wz$c536®®

or 25(5458 LG ©

W205 ZSCSSB

R2333)

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Fig. 21
(Reverse Si

Fig. 22 RECORDING" AMP. PC. BOARD
KD-ASOll (Face Side)

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R222 4.7K BIO/25 vim-o
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GX-280

RECORDING AMP. P.C. BOARD KD-ASOll

de)

Line I
output _0

High
Sensitivity
V.T,V.M.

Fig. 20

2. RECORDING LEVEL ADJUSTMENT

(See Figs. 20, 21 & 22)

1) Connect an Audio Frequency Oscillator to the
Line input terminals through an Attenuator and
connect a High Sensitivity V.TiV.M. to the Line
output terminals.

2) Depress the 7-1/2 ips Tape Speed Switch, set

Line Recording level controls and Volume controls
to maximum, set SND ON SND Switch to OFF
position and depress the STEREO Track Selector.

3) Set Monitor Switch to TAPE position, set SiR.T.
Switch to OFF position, and load a FUJI S-lOO
blank tape.

4) Set recorder to recording mode and supply a

1,000 Hz signal from the Audio Frequency
Oscillator. Adjust the Attenuator to obtain a
V.T.V.M. indication of 4 dB (1.228V).

5) Set the Monitor Switch to SOURCE position and
adjust Recording Amps P.C. Board recording
level adjustment semi-fixed resistors VR201 5
kB (left ch.) and VR201b 5 kB (right chi)
shown in Fig. 16 to obtain a Line output level
of 4 dB

18

Page 37

FIG. 1 ILLUSTRATION 0F KG HEAD BLOCK

38

Page 50

SYS. CON. P.C. BOARD FIG. 11 PHOTO OF OSC. P.C. BOARD

(KD-AIOOIA) BLOCK (KD-A5004)

3):? Parts No. Description Qty
lCI-ix BA426284 Sys. Con P.C. Board Comp.

(KDAIOOIA) 1
10-TR101 to 8 ET398711 Transistor 2SC945(Q)(R) 8
10-TR109 i011 ET338894 Transistor ZSC968(3) 3
lO-D101,2,3 ED224526 Silicon Diode lDDl 3
lO-D104 ED219464 Germanium Diode 1N34A l
10-D106,7,8 ED219464 Germanium Diode 1N34A 3
lO-Dllo ED224526 Silicon Diode 10Dl J
10»l)111 to 15 ED219464 Germanium Diode 1N34A S
10-D116tol9 ED224526 Silicon Diode 10Dl ' 4
l0-Dl20 to 22 ED219464 Germanium Diode 1N34A 3
10-Dl23 ED224550 Silicon Diode 10D4 l
10-D124, 5 ED219464 Germanium Diode 1N34A Z
10»Dl26 ED224526 Silicon Diode lODl l
10-D127 ED224550 Silicon Diode 10D4 l
10»RLl01 to 6 EP344136 Relay MY4-O-US-AD4-24V 6
10~CR101, 2 ER376424 Spark Quencher U/L

0,111+120 SOOWV 2

10»VR101 EV426936 Semirfixed Volume

VlOK-S 30 kB 1
lOrVRlO2 EV221826 Semi»fixed Volume

VlOK-S 10 kB 1

Capacitor, Vertical Type

OSC. P.C. BOARD (KD-A5004) BLOCK

10-C101. 2 EC456041 Elect. 331115 25wv 2
10-c103 EC2206I2 Elect. 331m 25wv 1 symbol
10-C104 EC308711 Mylar 0.04711F(K) 50wv 1 N0» Parts NO- Description Qty
10-C1os, a, 7 15C220994 Elect 101115 25wv 3
10cm; EC273464 MP 0.111F(M) ssowvoc 11-111 BA426352 030 PC- Board Comp-
(rub.1ypo) 1 (KDASOOU 1
10.13109 150220512 Elem 33uF 2swv 1 11-TR301.2 51304255 Transistor 2SC971(2)(3) (red) 2
10.0110 EC220994 Elect. 10}? 25wv 1 11-L301 130383365 OSC. Coil 0T-204 l
11-RL301 EP383321 Relay TECK-36 DC22\1000 1
Resistor, Stopper Type 11-TC301, 2 150125250 Trimmer/C. 4-1113-3 70PF 2
10-11101 ER211465 Carbon 1101/4 111(1) 1
10-11102 ER362485 Carbon 1101/4 330110) 1 Capacitor, VeIticalTypfi
10-11103 1511336442 Carbon 1101/4 101(1) 1 11-0301 EC520492 Styrol 5600PF(J) 500W
10-11104, 5 ER212883 Carbon 1101/4 4.711(1) 2 (Tuh- type) 1
lO-RlDé ER362485 Carbon RBI/4 330k(J) 1 ll-C302 EC220678 Elect. 4711F ZSWV 1
10-11107 1511212333 Carbon 1101/4 4.711(1) 1 11-C303: 4 EC250841 Mylar 0-01#F(J) 50WV 2
10»R108 151121 1465 Carbon 1101/4 lk(1) 1
10-11109 ER212883 Carbon 1101/4 4.711(1) 1 Resistor, Stopper Type
10.51110 ER357456 Carbon RD1/4 2311(1) 1 11R301 ER398856 Metal Oxide Film 1W 1110(K) 1
1011111 011343073 Carbon 1101/4 2.711(1) 1 JUN 1511212333 Carbon RBI/4 4-7110) 1
10-11112 ER212883 Carbon 1101/4 4.711(1) 1 11-11303 1511304402 Carbon 1101/4 470(1) 1
10-11113 ER357456 Carbon 1101/4 2.211(1) 1 11-11304, 5 1511315944 Carbon 1101/4 313(1) 2
10-11114 ER343078 Carbon 1101/4 271(1) 1 11-R306 ER426892 Solid RC1/2 2.411(1) 1
10-11115 1511212333 Carbon 1101/4 4.711(1) 1
10-11116 ER357456 Carbon 1101/4 2.211(1) 1
10-11117 ER343078 Carbon 1101/4 2.711(1) 1
10-111 18 1511391623 Metal Oxide Film 1w111(1() 1
10-11119 ER357456 Carbon 1101/4 2.211(1) 1
10-11120 1511213300 Carbon 1101/4 680(1) 1
10-11121 ER391623 Metal Oxide Film 1w 1k(K) 1
10-11122 ERS39065 Carbon 1101/4 l.6k(K) 1
10-11123 1511213300 Carbon 1101/4 680(1) 1
10-11124 ER211667 Carbon 1101/4 100(1) 1
1011125 ER336442 Carbon 1101/4 1011(1) 1
10-11126, 7 ER2ll465 Carbon 1101/4 111(1) 2
10-11123 ER212883 Carbon 1101/4 4.711(1) 1
111-11129 1511213030 Carbon 1101/4 5.611(1) 1
10-11130 1511211465 Carbon 1101/4 111(1) 1
10-11131 ER336442 Carbon 1101/4 1011(1) 1
10-11132 1511211465 Carbon 1101/4 111(1) 1
113-11133 ER380147 Carbon 1101/4 10(1)
([0511. type) 1
10-11134 1511304290 Carbon 1101/4 10(1) 1

When ordering parts, please describe Parts Number, Serial Number, and Model Number in detail.

51