Ntsc Hi-Fi Audio Deviation Adjustment - Panasonic AG-7350 Series Service Manual

5-3-56. NTSC Hi-Fi AUDIO DEVIATION
ADJUSTMENT
1.
2.
3.
4.
5.
6.
TP ADJ. MODE INPUT
TP4704 VR4704
NTSC
1kHz, -8dBv
TP4708 VR4712
STOP SINEWAVE
TAPE
M. EQ. SPEC.
BLANK
SPECTRUM
fw=100kHz +1-5kHz
TAPE
ANALYZER
Set the TV system switch to the NTSC position.
Set the signal generator to 1KHz, -8dBv and
supply it to the Hi-Fi Audio Inputs (CH1/CH2).
Connect the spectrum analyzer to TP4704 and
set its centre frequency to 1.3MHz.
Adjust VR4704 (CH 1) so that the width of fw
portion becomes 1OOKHz +/- 5KHz as shown
below.
Re-connect the probe of spectrum analyzer to
TP4708 (CH2) and set its centre frequency to
1.7MHz.
Adjust VR4712 (CH2) so that the width of fw
portion becomes 100KHz +/-5KHz as shown in
Figure E50.
~----------tw------------~
fw=100kHz±5kHz
Figure E50
5-3-57. Hi-Fi AUDIO REC CURRENT
ADJUSTMENT (FOR AG-7350)
TP ADJ.
MODE INPUT
TP5001 (HOD
VR4706 PAL
NO SIGNAL
VR4709
RECORDING
TAPE M. EQ. SPEC.
BLANK TAPE
OSCILLO- CH1:80mVp-p +1- 5mV
SCOPE CH2: 260mVp-p +I- 5mV
1. Make the short circuit between both Hi-Fi
audio Inputs (CH1/CH2) and GND.
2. Place the unit in the recording mode.
3. Fully close VR4709 so that the CH2 recording
current is cut.
4. Connect the oscilloscope to TP5001 (HOT).
5. Adjust VR4706 for 80 +/-5mVp-p as shown in
Figure E51.
6. Adjust VR4709 for 270 +/-5mVp-p as shown in
Figure E52.
I
I,
I
80mVp-p±5mV
Figure E51
Figure E52
5-3-58. Hi-Fi AUDIO PLAYBACK LEVEL
ADJUSTMENT (FOR AG-7150)
TP ADJ. MODE INPUT
Hi-Fi AUDIO VR4704 PAL
X
OUT (CH1/CH2) VR4712
PLAY
TAPE
M. EQ. SPEC.
-8dBv, 1kHz
RECORDED
V.T.V.M -8dBv± 1
TAPE
1. Prepare the prerecorded tape which recorded
a audio 1kHz, -8d8v signal on another set such
as AG-7350.
2. Play back the prerecorded tape.
3. Connect the V.T.V.M to Hi-Fi Audio outputs
(CH1/CH2).
4. Adjust VR4704 (CH 1) or VR4712 (CH2) so that
the reading of V.T.V.M is -8d8v +/-1dBv.
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