Checks
and
Adjustments
Amplitude Check
1.
Obtain a display as described
in
"Initial Setup."
2.
Set the VOL TS/DIV switch to 100 mV, the SEC/DIV switch
to
1 ms, and
20
MHz BW LIMIT on.
3.
Adjust the
CH
1 POSITION control to center the display on the screen.
4.
CHECK-Amplitude
of
the CALIBRATOR signal is between 3.88 and 4.12
divisions as measured on the center
vertical graticule line.
5.
Select
t:..V
and carefully superimpose the cursors on the high and low levels
of the waveform. CHECK-t:..V readout
is
between 392 mV and 408 mV.
6.
Repeat this procedure using the Channel 2 connector and controls.
Timing Check
The period
of
the CALIBRATOR signal automatically tracks the A SEC/DIV
setting within the range of 100 ms
to
100 Ils. Within that SEC/DIV range, the
CALIBRATOR period is
200 ms
to
200 ns, 5 cycles per 10 divisions
of
the A
Sweep. To quickly check the operation and calibration of the oscilloscope timing,
use the
following procedure:
1.
Obtain a display as described
in
"Initial Setup."
2.
CHECK-Timing
accuracy by confirming that five complete cycles
of
the
square-wave
signal are displayed over 10 major divisions
(±
0.1
division)
along the center horizontal graticule line for
all
A SEC/DIV settings from
100 ms
to
100 ns. Confirm that 2 cycles of the Calibrator signal cover 8
divisions at
50 ns/div and that 1 cycle covers 10 divisions at 20 ns/div.
Observe that the
displayed transition time of the signal remains
approximately the same when A SEC/DIV is changed
to
10 ns and 5 ns.
(The number of
horizontal divisions covered by the transition time at 10
ns
per division should
be
two times the number covered at 20 ns, and the
number of divisions at 5
ns
should
be
four times the number at 20 ns.)
Return A
SEC/DIV
to
1 ms, switch the X10 MAG on, and
CHECK-that
1/2 cycle covers 9.8
to
10.2 divisions.
3.
Set X10 MAG Off and carefully align the
t:..t
cursors with the falling edges of
the first and fifth
cycles. CHECK-t:..t reading is within 7.93 ms to 8.07
ms.
Repeat the test at any A-Sweep speed
in
the 100 ms
to
100 ns range.
4.
If deSired, delay timing can
be
checked by using Alt horizontal display
mode,
RUN
AFT DL Y B-Trigger mode, and
t:..t.
Set the
t:..
REF
AND DL Y
POS and
t:..
controls
to
align the intensified zones with the falling edges of
the first and fifth
cycles and superimpose the expanded display of the
edges on the B
Sweep, running at least 10 times faster than the A Sweep.
CHECK-t:..t
reading is 8 times the A SEC/DIV setting, ± 0.5%.
2465A/2455A/2445A Operators
4-5
To Next Page
Loading...
Need help?
General
