Panasonic Palmcorder VHSC PalmSight PV-L759 Service Manual page 88

2. A/C HEAD HEIGHT ADJUSTMENT
The height of the A/C Head replacement part is preset at the
factory.
Purpose:
To be sure the tape runs properly along the Control
Head.
Symptom of Misadjustment:
If the control signal is not properly picked up, Servo
Operation can not be achieved.
1. Connect the oscilloscope to Pin 25 (PB Control signal)
on the TP Adjustment P.C.B.
2. Play back the Alignment Tape (VFMW0001C)
3. Confirm that the Sub Control Signal is 500 +/- 200 mV. If
not, slightly and equally adjust Screw A, Screw B, and
Screw C on the A/C Head Unit to achieve the sub control
signal level of 500 +/- 200 mV.
(Sub Control Signal level will decrease when rotating
screws clockwise, and increase when rotating screws
counterclockwise.)
500 ± 200 mV
Pin 25 on TP Adjustment P.C.B.
Fig. M4-1
Screw A
(Height)
Fig. M4-2
Sub Control
Signal
Screw C (Azimuth)
Screw B (Tilt)
3. A/C HEAD AZIMUTH ADJUSTMENT
Purpose:
To adjust the position and height of the A/C Head so that
it meets the tape tracks properly.
Symptom of Misadjustment:
If the position of the A/C Head is not properly adjusted,
the Audio S/N Ratio will be poor.
1. Connect the Audio/Video Cable on the camcorder.
2. Connect the oscilloscope to audio output jack.
3. Playback the Alignment Tape (VFMS0004H6C).
4. Adjust Screw C (Azimuth) on the A/C Head Unit so that
the output level is at maximum.
Oscilloscope
5. Confirm and readjust the A/C Head height.
6. Confirm and readjust Screw C (Azimuth) on the A/C head
so that the output audio becomes is maximum.
2-40
6 kHz - Audio
Make its
maximum
Fig. M5