Rec/Pb Head Azimuth; Head Height; Head Block Projection - Akai HX-R44 Service Manual

6-1 TAPE GUIDE ADJUSTMENT
(Refer to Figs. 6-1, 6-2 & 6-4)
1) Use a mirror Cassette Tape (AT-751178) shown in
Fig. 6-3 for better visibility of the head area, and
select PLAY mode.
2) Adjust the tape guides A and B by turning the tape
guide height adjustment nuts () and (b) in Fig. 6-2,
so that the tape runs smoothly by the lower edge of
both tape guides, and the tape is not hitched by
those tape guides.
6-2 REC/PB HEAD AZIMUTH ADJUSTMENT
Playback a 10 kHz Head Azimuth Adjustment Tape
(AT-750778) and adjust the screws () (FWD direc-
tion) and @ (REV direction), so that the levels of both
channels are maxima. (NOTE: Avoid turning the screws
too far as other false maxima exist further away on both
sides of the correct position.)
6-3 HEAD HEIGHT ADJUSTMENT
This adjustment is not necessary since HX-R44 is equip-
ped with Roatary Head System (with Erase & REC/PB
combination head). However, the confirmation of head
height is necessary and it can be done as follows.
1) Confirm the azimuth in item 6-2.
2) Playback a 315 Hz (or 333 Hz) PB Level Adjustment
Tape (AT-750773) in FWD Play mode, and adjust the
PB level Adjuster (VR5 on Pre-Amp P.C Board) so
that the LINE OUT level of left channel is —5.5 dBm.
Then, check the level of the same channel in REV
mode. The difference in level between FWD and REV
modes should be within +1 dBm. (—4.5dBm to
—6.5 dBm)
3) If the difference is more than +1 dBm in item 2),
adjust the tape guides A & B by turning both Tape
Guide Height Adjustment screws @ & 'b in the
same direction by 1/4 turn (40.1 mm), so that
difference is within +1 dBm.
4) The Head Height Adjustment is necessary if still the
difference could not be corrected by above adjust-
ment. It can be done by changing the Head Height
Adjustment Spacers @G) & (k) . (The thicknesses
of these spacers are G) = 0.45mm, G) & & =03
mm).
Loose the screws ©) @ & @) the spacer replace-
ment.
If the level is lower in REV mode, it means that the
head is too hight, therefore replace the spacers by
thinner ones. When the level is higher in REV mode,
replace them by thicker ones.
After the replacement of those spacers, do the same
adjustment in items 1) and check the level of LINE
OUT is —5.5 dBm + 1 dBm.
For the further confirmation, playback a 4 Track
Head Height Adjustment Tape (1 kHz/4 Track,
AT-750775). LINE OUTPUT level of both channels
should be more than --8 dBm and the difference in
level of both channels should be more than —8 dBm
and the difference in level between FWD and REV
modes should be within +1 dBm. Otherwise do the
fine adjustment in the same manners as item 3) & 4).
5) When the head replacement is necessary, loosen only
the screws (@) & (b) in Fig. 6-1 for easy replacement.
6-4 HEAD BLOCK PROJECTION ADJUST-
MENT (Refer to Figs. 6-2 & 6-3)
Use a cassette Head Projection Gauge (AT-751180)
and select FWD or REV play mode.
Loosen the screw (h) and adjust Chassis Head Part
@ so that the gauge indication at the time is 3.2 +
0.15 mm.
After the adjustment, apply paint-lock on the screw
ch).