S-Vhs Recording Current Adjustment (For Ag-7350); Vhs Y Recording Current Adjustment (For Ag-7350); Vhs Y Playback Level Adjustment (For Ag-7350) - Panasonic AG-7350 Series Service Manual

....
z
w
::::E
....
0
:::::>
..,
c
c(
...J
c(
0
a:
....
0
w
...J
w
5-3-19. S-VHS RECORDING CURRENT
ADJUSTMENT (FOR AG-7350)
TP ADJ. MODE INPUT
TP5003 (HOT) VR5002
(C) PALS-VHS
COLOUR BAR
TP5002 (GND) VR5001 (Y)
RECORDING
TAPE M. EO. SPEC.
S-VHS OSCILLO- 35mVp-p±2mV (C)
BLANK TAPE SCOPE 150mVp-p± 10mV (Y)
1. Supply a colour bar signal to the video input.
2. Place the unit in the S-VHS recording mode.
3. Connect the oscilloscope to TP5003 (HOT) and
TP5002 (GND).
4. Before the chrominance recording current
adjustment, the luminance recording current
(VR5001) should be closed to observe the
chrominance signal.
(In another way, the luminance current can be
closed -_by making
~.the
short circuit between
TP3007' and TP3006)
5. Adjust VR5002 so that the cyan level is 35 +/-
2mVp-p as shown in Figure E 16.
TP5003 (HOT)
TP5002 (GND)
CYAN LEVEL: 35mVp-p±2mV
Figure E16
6. Next, adjust VR5001 so that the luminance
signal level is 150 +/- 10mVp-p as shown in
Figure E17 .
TP5003 (HOT)
TP5002 (GND)
(V. RATE)
----~r-1~----------~
!
150mVp-p± 10mV
----.LJ..------,}
r==
l
V-SYNC
Figure E 17
5-10
5-3-20. VHS Y RECORDING CURRENT
ADJUSTMENT (FOR AG-7350)
TP ADJ. MODE INPUT
TP5003 (HOT)
VR3002
PALVHS
COLOUR BAR
TP5002 (GN D) RECORDING
TAPE M. EQ. SPEC.
BLANK OSCILLO-
150mVp-p± 10mV
TAPE
SCOPE
Note: This adjustment should be always completed
after the S-VHS recording current
adjustment.
1. Supply a colour bar signal to the video input.
2. Place the unit in the normal VHS recording
mode.
3. Connect the oscilloscope to TP5003 (HOT) and
TP5002 (GND).
4. Adjust VR3002 so that the luminance signal
level is 150 +/- 1 OmVp-p as shown in Figure
E18.
TP5003 (HOT)
TP5002 (GND)
(V. RATE)
----~r-1~----------~
c:=r
150 mVp-p ± 10 mV
----.ur-------.}
r==
~
V-SYNC
Figure E18
5-3-21. VHS Y PLAYBACK LEVEL ADJUSTMENT
(FOR AG-7350)
TP ADJ. MODE INPUT
VIDEO
VR3503
PALVHS
COLOUR BAR
OUTPUT 1
PLAY
TAPE M. EQ. SPEC.
SELFE
OSCILLO-
RECORDED
SCOPE
1.0Vp-p±0.02V
TAPE
Note: This adjustment should be always completed
after completion of all adjustment on the
recording loop.
1. Supply a colour bar signal to the video input
and recording it in the normal VHS mode for a
few minute.
2. Connect the oscilloscope to the video output
with 75ohm termination.
3. Play back the just recorded portion.
4. Adjust VR3503 for 1.0 +/-0.02Vp-p as shown in
Figure E19.
VIDEO OUT 1
(H. RATE)
----- ---1
1.0Vp-p±0.02V
-__ l
with 750 Termination
Figure E 19