Playback Preamplifier Adjusment - Sony AV-3600 Service Manual

Adjustment/
Board:
R225/V2
(Rec. Current)
R217/V2 (Rec. Current Balance)
Signal
Source:
Camera
or telecast signal.
Equipment
Required:
Procedure:
(1)
Oscilloscope
(2)
SONY
AV-Series camera
or
TV
monitor.
1.
Set
up
the E-to-E
mode
using
a
camera
or
tele-
cast signal.
2.
Connect
the
scope
to
TP-203. Set the
time base
to
2
msec/cm.
3.
Adjust
R225
for a
1
V
(p-p)
output
as
shown
in
Fig.
5-3 (a).
4.
Connect
the
scope
to
TP-204.
5.
Adjust
R217
to equalize the
amplitude
at
TP-204
to that at
TP-203
in
Step
3.
5-4.
PLAYBACK PREAMPLIFIER
ADJUSTMENT
(Head Resonance and Playback Equaliza-
tion)
Frequency characteristics
of the
playback ampli-
fiers
are
adjusted to
equalize head-to-tape characteris-
tics
and to obtain the desired
overall
frequency
response.
Test
Point
I
Board:
Adjust
for:
TP-201/V2(PBrf
output)
Correct
frequency response
as
shown
in Fig. 5-4.
A:B:C=
1 :
3.5
:
4
Adjustment/
Board:
C201,
R201/V2
(Head Resonance,
ChA)
C202,
R202/V2 (Head Resonance,
ChB)
L204/V2 (PB
Equalization)
R21 1/V2 (PB
Equalization)
Signal
Source:
Rf
signal:
500 kHz,
3.5
MHz &
4.5
MHz
Equipment
Required:
Set-up:
(1)
Oscilloscope
(2)
Rf
signal
generator
See Fig. 5-5.
Video
Head
A
to
RF
signal
generator
ox
>V
_
75
n
m
*
i
V2
Board
Fig. 5-4.
Playback
preamplifier frequency
response
Fig, 5-5. Set-up for adjusting video-heat
resonance
5-E5