Sanyo FISHER V95I Manual page 32

4-3-4. AUDIO R/P HEAD (ACE HEAD)
HEIGHT ADJUSTMENT,
AZIMUTH ADJUSTMENT AND
HORIZONTAL POSITION ADJUSTMENT
(1) Azimuth adjustment (See Fig.4-3-5)
1) Play the alignment tape (NTSC: VHJ-0005, PAL: VHJ-
~ 0008) and observe the waveform of the audio output,
using an oscilloscope.
2) Loosen the height adjustment screw in the counter-
clockwise direction and decrease the amplitude of the
audio output waveform. In this state, tighten the screw
in the clockwise direcion and maximize the amplitude.
Slightly tighten the screw further in the clockwise
direction and decrease the amplitude, and then loosen
it slowly in the counterclockwise direcion until the
amplitude starts to reach the maximum.
3) Set the amplitude of the audio output waveform to
maximum by rotating the azimuth adjustment screw.
4) Make sure that the tape edge is running between the
top of the audio head and the bottom of the control
head.
Gaps A and B should be roughly equal.
NOTE:Rotate the adjustment screw with a slotted
screwdriver. Do not apply excessive force vertically. As
the height adjustment screw also adjusts tilt, rotate
it slowly. Do not rotate it excessively. And apart from the
this screw, and height adjustmment screw, the screws
is precisely adjusted before shipment from the factory,
and should not be tampered with. Tampering with these
screws can lead to scratching of the tape and other
problems.
(ACE Head)
Height adjustment
screw
This screws is precisely
adjusted and should not be
tampered with.
Audio head
Tape
Control head
Fig.4-3-5
(2) Horizontal position adjustment (See Fig.4-3-6)
1) Play the alignment tape (NTSC: VHJ-0006, PAL: VHJ-
0009).
2) Press the tracking buttons (channel + and channel - )
simultaneously and set the tracking to the centre.
3) Using an oscilloscope, observe the waveform of the
video head output.
4) Loosen the two fixed screws on the audio R/P head
(ACE head) by between 20° and 30° anticlockwise.
5) Using a slotted screwdriver, adjust the position of
the audio R/P head (ACE head). At the position where
the amplitude of the envelope waveform is at its
maximum at the tracking centre, tighten the fixed
screw on the audio R/P head (ACE head). When you
do this, check that the envelope waveform changes
equally whether the tracking is shifted by pressing
the tracking button in the plus or the minus direction.
6) Play the alignment tape (NTSC: VHJ-0007 PAL: VHJ-
0052) and check that the amplitude of the envelope
waveform is at its maximum at the tracking centre. If
not, repeat steps 1) to 6).
7) Refer to the electrical adjustments section of the
service manual, and adjust the switching position of
the servo circuit.
NOTE:
1. When you press the tracking buttons (channel + and
channel—) simultaneously, the tracking is reset to the
tracking centre. When the tracking is at the tracking
centre, the message "T -: - " will appear in place of the
clock display on the front panel. If you keep pressing
the channel - button the messages "T -: " and "T - -: "
will appear, while if you keep pressing the channel +
button, the messages "T :-" and "T :--" will appear.
Three seconds after you stop pressing the tracking
buttons, the clock display will re-appear.
2. The check described in paragraph 6) is not necessary
for models in which the only tape speed is SP mode.
After resetting the tracking to the
tracking centre, set the envelope
screwdriver
<«—
Audio R/ P head assembly
Fig.4-3-6