Fine Adjustment Of The A/C Head Height; Coarse Adjustment Of The A/C Head Horizontal Position (X-Value); Fine Adjustment Of The A/C Head Horizontal Position (X-Value) - Panasonic AG-7350 Series Service Manual

4-2-7. FINE ADJUSTMENT OF THE A/C
HEAD HEIGHT
<<NOTE>>
Before this adjustment 5-2-3. Coarse Adjustment of the A/C
Head Height should be performed.
<<TOOL>>
Alignment Tape ; VFM8180HADH
Nut Driver ; Purchase locally
1. Connect a scope to the Normal Audio CH2 Output on
the rear panel.
2. Play back the 2-nd portion (Normal Audio 10kHz) of the
Alignment Tape (VFM8180HADH)
3. Adjust the Nut (A) (Figure M24) so that the CH2 output
level becomes maximum as shown in Figure M25.
A/C Head Base Unit
Figure M24
MMf_
Figure M25
4-2-8. COARSE ADJUSTMENT OF THE
A/C HEAD HORIZONTAL POSITION
(X-VALUE)
<<NOTE>>
This procedure should be performed only when the A/C head
is
replaced, and after performing the tape interchangeability
adjustment.
<<TOOL>>
H-Position Adjustment Screwdriver VFK0328
Alignment Tape ; VFM8180HADH
1 . Set the Tracking Control VR to the center detent(fixed)
position.
2. Connect a scope CH 1 to TP3005 (RF) on the video (1)
board, CH2 to the audio CH1 output on the rear panel.
3. Play back the 4-th position (Monoscope 3 and Audio
1
Every 10-th field is skipped) of the Alignment tape
VFM8080HQFP.
4. Adjust the
NC
head horizontal position screw so that
the phase of audio drop out and video RF envelope
drop-out becomes the same as shown in Figure M26.
Horizontal Position Screw
Video RF
Audio
Drop Out Portions
Figure 3-26 Horizontal Position Adjustment of
NC
Head
<<NOTE>>
After completion the fine adjustment of the A/C head horizontal
position, the phase of Audio drop-out and Video RF envelope
drop-out may be changed slightly.
4-2-9. FINE ADJUSTMENT OF THE A/C
HEAD HORIZONTAL POSITION
(X-VALUE)
<<NOTE>>
This procedure should be performed only when the A/C head is
replaced, and after performing the tape interchangeability
adjustment.
<<TOOL>>
H-Position Adjustment Screwdriver VFK0328
Alignment Tape ; VFM8180HADH
1 . Set the Tracking Control VR to the center fix position.
2. Connect a oscilloscope to Video RF test Terminal on
the Front Panel.
3. Play back the 2-nd portion (Monoscope 2) of the align-
ment tape (VFM8180HADti)
4. Adjust the Horizontal Position Screw (Figure M25) of
N
C head so that the RF signal becomes maximum level
as shown in Figure M27.
Head Amp Output (RF Signal)
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Jximum
----~,.~
_ _
L_I_~
4-9
Figure M27
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