Adjustment Procedure-2445A/2455A Service
AUTOMATIC CALIBRATION CONSTANTS, HORIZONTAL AND
VERTICAL GAIN, CENTERING, AND TRANSIENT
RESPONSE ADJUSTMENTS
NOTE
Within the following procedure, the calibration constants for timing, vertical gain and trigger level are generated by the
system microprocessor and are stored in nonvolatile memory.
The
adjustments
in
CAL
01,
02,
03,
and
04
should be
performed in numerical sequence;
i.e.,
CAL
01
should
be
done before CAL
02,
CAL
02
should be done before
CAL
03,
etc. Performing partial procedures
(i.e.,
only one
or
two
of
the
CAL
steps)
is
not
recommended and should only be
done
if
the calibration constants that would have been set
in
the preceding steps are known to be correct.
The
CAL functions are available only
if
the CAUNO
CAL
jumper
(P501
on the Control Board)
is
in
the CAL position
(between pins 1 and 2)
when
power is turned
on.
When
the automatic calibration procedures are completed, return
the jumper to the
NO
CAL
position to prevent entry into the calibration routines.
Equipment Required (see Table 4-1)
Calibration Generator (Item 3)
Time-Mark Generator (Item
6)
Oscilloscope (Item 7)
50
0 BNC Cable (Item 10)
5X
Attenuator (Item 17)
Digital Multimeter (DMM) (Item 19)
Alignment Tool (Item 20)
Tunnel Diode Pulser (Item
23)
See
ADJUSTMENT LOCATIONS 4
at
the back
of
this manual for test point and adjustment locations.
INITIAL CONTROL SETTINGS
CALJNO
CAL jumper
CAL position (between
pins 1 and
2)
prior
to
turning on power
NOTE
When
performing the automatic CAL steps, the
initial setup
of
front-panel controls is
not
required.
CAL
01-HORIZONTAL
1.
Check/Adjust Horizontal Timing,
X1
Gain
(R860), X10 Gain (R850), Hrz Ctr (R801), and Trans
Resp (R802).
a.
Simultaneously press
in
and
hold the
.:1t
and the
.:1
V
push buttons, then press
and
hold the SLOPE switch.
Hold
all
three switches
in
for approximately one second,
then release them.
5-10
b.
CHECK-Top
line
of
the readout display says:
"DIAGNSTIC.
PUSH
A/B
TRIG TO EXIT".
NOTE
The
•menu·
of
calibration, test, and exercise rou-
tines is
in
a loop that may
be
scrolled through in sin-
gle steps, either forward
or
backward. Pressing the
upper
or
lower
TRIGGER
MODE switch and releas-
ing
it
respectively increments
or
decrements the
menu position by
one.
As
each routine
is
selected,
its name appears
in
the lower left comer
of
the
readout display.
When
performing a calibration step, touch only the
specific control
or
controls called out
in
the pro-
cedure. Movement
of
other controls may cause
erroneous calibration results.
c.
Scroll
to
CAL 01.
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