Before Adjustment - Akai HX-27W Service Manual

il. ADJUSTMENT
{ PRECAUTIONS BEFORE ADJUSTMENT }
1. Before adjustment, clean and de-magnetize the heads
and tape guides.
2. Set the switches and control knobs as follows.
REC LEVEL control : Maximum (10) position
REC BALANCE control : Center (click) position
Dolby NR switch : OFF
3. Use the following recording test tapes.
NORMAL position : MAXELL UD1 60
CrO2 position : TOK SA 60
METAL position : TOK MA 60
4.0 dBs = 0.775 V
ADJUSTMENT ITEM
1. TEST TAPE / INPUT SIGNAL
2. MODE
3. TEST POINT, ADJUSTMENT PART
4. REMARKS (#) and RESULT (-*)
ADJ.part
11 TAPE I! CrO2 POSITION BIAS
1.400 Hz and 12.5 kHz,-25 dBs (LINE
OUT)
2.REC — PLAY (PB)
3.LINE OUT, VR503 (L & R-ch)
4.eConnect an AC milli-voltmeter to LINE
OUT.
*Playback levels of 400 Hz and 12.5 kHz
are equal or within +1.0 dB
| 10| TAPE It NORMAL POSITION BIAS
1.400 Hz and 12.5 kHz, -25 dBs (LINE
OUT}
2.REC + PLAY (PB)
3. LINE OUT, VR504 (L & A-ch)
4.eConnect an AC milli-voltmeter to LINE
OUT.
*Playback ievels of 400 Hz and 12.5 kHz
are equal or within +1.0 dB
OSC FREQUENCY (TAPE II REC / PB only)
1.No signal input, METAL recording test tape.
2.REC
3. TP702 (GND) and CN3 white wire, L503
4. eConnect a frequency counter between TP702
(GND) and CN3.
*105+0.5 kHz
'9 | TAPE I! METAL POSITION BIAS
1.400 Hz and 12.5 kHz, -25 dBs (LINE
QUT)
2.REC -» PLAY (PB)
3. LINE OUT, VR502 (L-ch) / VR501 (R-ch) SCREW
4.eConnect an AC milti-voltmeter to LINE
OUT.
*Playback levels of 400 Hz and 12.5kHz
are equal or within +1.0 dB
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4 TAPE !l NORMAL TAPE SPEED _
1.3,150 Hz test tape (AT-751263)
2.PLAY
3.LINE OUT, VR702
4.eConnect a frequency counter to LINE
OUT.
*3,150 +10 Hz
|5 | HEAD AZIMUTH ALIGMENT (TAPE | & II)
1.10 kHz, -15 VU test tape (AT-750778)
2. PLAY
3.LINE OUT, HEAD AZIMUTH ALIGMENT
4.eConnect an AC milli-voltmeter to LINE OUT.
*Maximum output level.
LINE LINE
IN DUT
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MAIN PCB
3. TAPE #! HIGH (x2) TAPE SPEED
1.3,150 Hz test tape (AT-751263)
2. PLAY
3.LINE OUT, VR701
4.¢Connect a frequency counter to LINE
OUT and connect between TP701 and
TP702 to set the X2 tape speed.
*6,300 +10 Hz
1__ TAPE | HIGH (x2) TAPE SPEED
1.3,150Hz test tape (AT-751263)
2.PLAY
3.LINE OUT, VR703
4.eConnect a frequency counter to LINE |
OUT and connect between TP701 and
TP702 to set the X2 tape speed.
*6,300 +10 Hz
12; TAPE REC LEVEL
| 1. NORMAL tape, 1 kHz, -6.5 dBs (LINE
OUT)
2. REC - PLAY (PB)
3. LINE OUT, VR401 (L-ch) / VR402 (R-
ch)
4. eConnect an AC milli-voltmeter to LINE
OUT.
*-6.5dBs
TAPE it PB LEVEL
1.315 Hz test tape (AT-750773)
2. PLAY
3. LINE OUT, VR201 (L-ch) / VR202 (R-ch)
4,¢Connect an AC milli-voltmeter to LINE
OUT.
*-6.5 dBs
6, TAPE | PB LEVEL
1.315 Hz test tape (AT-750773)
2. PLAY
3. LINE OUT, VR101 (L-ch) / VR102 (R-ch)
4.eConnect an AC milli-voltmeter to LINE
OUT.
*-6.5 dBs
2 TAPE | NORMAL TAPE SPEED
1.3150 Hz test tape (AT-751263)
2. PLAY
3.LINE OUT, VR704
4.¢Connect a frequency counter to LINE
; OUT.
| 3,150 +10 Hz