Philips PM3208 - 5.3.20 Vertical Bandwidth; 5.3.21 Trigger DC Balance Adjustment; 5.3.22 Y-out DC Balance Adjustment; 5.3.23 Y-out Gain Adjustment

5-10
5.3.20
5.3.21
5.3.22
5.3.23
Vertical bandwidth
TEST EQUIPMENT
SETTING
REQUIREMENTS
SETTING AND
REQUIREMENTS
SETTING AND
REQUIREMENTS
ADJUSTMENT
SETTING AND
REQUIREMENTS
5 PERFORMANCE CHECK AND ADJUSTMENT PROCEDURE
Constant amplitude sine-wave generator
Vertical mode - A
Channel A AMPL/DIV - 10 mV
Apply a 50 kHz reference sine-wave signal to channel! A and
adjust the trace height to exactly 6 div.
Check that the trace height is = 4,2 div at 20 MHz.
Repeat for AMPL/DIV - 0,1 V.
Repeat for AMPL/DIV - 1 V.
NO
Repeat for channel B
Trigger DC balance adjustment
TEST EQUIPMENT
SETTING
ADJUSTMENT
SETTING
ADJUSTMENT
NO
Vertical mode - A
Channel A coupling - DC
Trigger coupling - AC
Apply the CAL signal to channel A and set for 2 div.
Turn
the
trigger
level,
to
position
the
trigger
point
at
the
centre
of
the
rising
edge.
Adjust
VR73
("TRIG
DC"
-
VERT
PCB)
for
minimum
movement
of
the
trigger
point
when
switching
the
trigger
coupling
switch
from
AC
to
DC.
Repeat for channel B.
Repeat for channel B by means of VR173 (VERT PCB).
Y-out DC balance adjustment
TEST EQUIPMENT
SETTING
ADJUSTMENT
NO
Vertical mode -A
Channel A coupling - GND
Channel A AMPL/DIV - 5 mV
Set the trace at the centre of the Y-axis.
Adjust
VR76
("CH
1
OUT"
-
VERT
PCB)
for
an
output
voltage
at
terminal
YA-OUT
(rear
side)
of
0
V
at
50
Q.
Y-out gain adjustment
TEST EQUIPMENT
SETTING
ADJUSTMENT
NO
Vertical mode - DUAL
Both channel A and B coupling - DC
Horizontal mode - MTB.
TIME/DIV - 0,2 ms
Apply
the
CAL
signal
to
channel
A
and
set
for
8
divisions.
Connect
the
signal
from
the
YA-OUT
terminal
at
the
rear
side,
termination
50
£2,
to
channel
B.
Adjust
VR77
("CH
1"
-
VERT
PCB)
for
8
divisions
at
channel
B.
Make
sure
that
channel
B
is
well
calibrated.
5.3
PERFORMANCE
CHECK
AND
ADJUSTMENT
PROCEDURE