Adjustment Procedure-2445A/2455A Service
CRT ADJUSTMENTS
Equipment Required (see Table 4-1)
Leveled Sine-Wave Generator (Item
2)
Time-Mark Generator (Item
6)
50 n BNC Cable
(2
required) (Item 10)
Digital Multimeter (Item 19)
Alignment Tool (Item 20)
See ADJUSTMENT LOCATIONS 2
at
the back
of
this manual for test point and adjustment locations.
NOTE
All CRT adjustments (other than the Front-Panel
ASTIG,
FOCUS,
and TRACE ROTATION adjust-
ments) are accessed through the High Voltage shield
located on the left side
of
the instrument near the
rear
of
the
CRT.
The
location
of
each adjustment is
indicated on the
shield.
INITIAL CONTROL SETTINGS
VERTICAL
CH1andCH2
VOLTS/DIV
CH
1 and
CH
2 VAR
CH
1
and
CH
2
Input Coupling
CH
2
and
BW LIMIT
CH
1,
CH
3,
CH
4
ADD and INVERT
ALT/CHOP
POSITION
HORIZONTAL
SEC/DIV
SEC/DIV VAR
POSITION
TRIGGER
MODE
SOURCE
COUPLING
SLOPE
LEVEL
HOLDOFF
5-4
100 mV
In
detent
1
Mn
GND
On
Off
Off
ALT
Midrange
X-Y
(knob
in)
In
detent
Midrange
AUTO LVL
VERT
DC
+ (plus)
Midrange
In
detent
Delta
t:i.V
and
t:i.t
TRACKING/INDEP
Display
INTENSITY
READOUT INTENSITY
SCALE ILLUM
FOCUS
Off (press and release
until readout
disappears)
INDEP
Visible display
SCALE FACTORS OFF
Fully CCW
Best focused display
1. Adjust ASTIG Preset (R977) and Grid Bias
(R1878)
a.
Position the dot
in
the center area
of
the graticule
using the
CH
1 and
CH
2 POSITION controls.
b.
Focus the displayed dot as well as possible using the
front-panel FOCUS control.
c. ADJUST
-ASTIG
(R977
on
the front panel),
in
con-
junction with the FOCUS control, for the sharpest possible
dot.
d.
Connect the Digital Multimeter + lead
to
cathode
of
CR2631 on the control board
and
the - lead
to
chassis
ground.
e.
Set the DMM
to
measure approximately 1.0 volt.
f.
Set the INTENSITY control knob for a DMM reading
of
1.00 volts.
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