30-Hz Pulse Adjustment; 30 Pg Pulse Lock Phase Adjustment; Servo Response-Time Adjustment - Sony AV-3600 Service Manual

6-4.
30-Hz
PULSE
ADJUSTMENT
This adjustment shapes the output of
MM404
into
a
50%
duty
cycle.
Incorrect
duty
cycle
may
cause servo
hunting or slow
lock up.
Test
Point/
Board:
TP-409/SV
(MV
output)
Adjust
for:
30-Hz pulse with a
50%
duty
cycle
Fig. 6-3.
30-Hz
pulse
adjustment
Adjustment/
Board:
R441/SV
(Pulse
Duty
Cycle)
Signal
Source: Telecast
signal
Equipment
Required:
(1)
Oscilloscope
(2)
TV
monitor
Procedure:
1.
Set
up
the E-to-E
mode
using a telecast signal.
2.
Connect the scope to
TP-409.
Set
the time base
to
5
msec/cm.
3.
Adjust
R441
so that the interval
"T"
in Fig.
6-3
is
16.7
±
0.5
msec,
i.e.,
a
duty
cycle of
50%.
TP-410
4.5
±0.5 V
T=
330±50}Js
—
*|
330
{Is
U—
Fig. 6-4.
Lock
phase adjustment
(REC/E-E mode)
Adjust
for:
Adjustment/
Board:
Signal Source:
Equipment
Required:
See
Fig. 6-4.
R454/SV
(Lock Phase)
Telecast
signal
(1)
Oscilloscope
(2)
TV
monitor
Procedure:
1.
Set
up
the E-to-E
mode
using
a telecast
signal,
2.
Connect
the
scope
to
TP-410.
3.
Set the
scope
for 5
ms/cm
horizontal
sweep
and
pull
out the
5X
magnifier.
Each
division
on
the time-base
now
represents
1
msec.
4.
Adjust
the
POSITION
control
on
the
scope
to
observe the
interval
"T"
in Fig. 6-4.
5.
Adjust
R454
to
set
the position of the 30
PG
pulse
with respect to the
30 Hz
multivibntor
ramp
as
shown by "T"
in
Fig. 6-5.
6-5.
30
PG
PULSE
LOCK PHASE ADJUSTMENT
This gain adjustment determines the location of
the
30
PG
feedback
pulse
on
the
30
Hz
MV
output
ramp.
Test Point/
Board:
TP-410/SV
(Integrated
30
Hz
pulse)
6-6.
SERVO
RESPONSE-TIME
ADJUSTMEMT
(Hunting)
Test Point/
Board: TP-410/SV
(Integrated
30
PG
pilse
output)
63