Akai GX-F91 Service Manual page 36

1. REC/PB HEAD PROJECTION
ADJUSTMENT
Set the cassette head projection gauge (TF-111CJ)
and set to PLAY mode. Loosen the screw (a) and
adjust so that the gauge indication at that time will be
3.2 + 0.05 mm. After adjustment, apply paintlock on
the screw (a).
2. TAPE GUIDE HEIGHT ADJUSTMENT
1) Set the mirror cassette tape (TF-109CM) and set
to PLAY mode.
2) Adjust the tape guide (A) so that the parts of the
erase head coming out of both sides of the tape
(A and A' in Fig. 2-13) will be equal. For the
adjustment, use the adjustment nut (A).
3) Adjust the tape guide (B) so that the tape runs
smoothly and is not hitched by the tape guide.
For the adjustment, use the adjustment nut (B).
4) After adjustment, paint-lock the adjustment nuts
(A) and (B).
3. REC/PB HEAD HEIGHT ADJUSTMENT
1) Set the mirror cassette tape and set to PLAY
mode.
2) Adjust the screws (b), (c) and (d) so that the upper
edge of REC/PB head Lch core and the upper side
of the tape is in alignment.
3) Playback the head height adjustment tape (4Tr
1,000 Hz) (TF-103CF), and fine-adjust the screws
(b), (c) and (d) so that the largest output is
obtained for both channels.
4. REC/PB HEAD AZIMUTH ALIGNMENT
ADJUSTMENT
1) Playback a 10 kHz Head Azimus Alignment Tape
(TF-106CH) and adjust the screw (d) until the
output levels of both channels are at maximum.
2) Record a 10 kHz, —20VU signal from the audio
frequency oscillator.
3) Rewind and check for any fluctuation in the out-
put level at playback.
4) After adjustment, paintlock the screws (b), (с) and
(d).
NOTES:
]. Be sure to clean the heads prior to head adjust-
ment.
2. Be careful not to use a magnetized driver or
other magnetized tools in the vicinity of the
heads.
3. Be sure to demagnetize the heads with a Head
Demagnetizer before and after head adjust-
ment.
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