Tektronix 2445A Service Manual page 102

Performance Check-2445A/2455A Service
Table 4-8
Horizontal Timing Accuracy Checked Against the Graticule
1 Div 2 Div 3 Div
Time-marker Accuracy ±0.07 ±0.07 ±0.08
(X10 MAG Off) Div Div Div
Time-marker Accuracy ±0.07 ±0.08 ±0.1
(X10 MAG On) Div Div Div
As Measured Against These Time-
1-2 1-3 1-4
Marker Pairs (X10 MAG Off Only)
2-3 2-4 2-5
3-4 3-5 3-6
4-5 4-6 4-7
5-6
5-7
5-8
6-7 6-8 6-9
7-8 7-9 7-10
8-9
8-10 8-11
9-10 9-11
10-11
g. Rotate the ~ REF OR DL
y
POS control
ccw
until
the cursor stops moving.
h. CHECK-~ REF cursor aligns with the 1st graticule
line within 0.2 division.
i. Rotate the ~
control CW until the cursor stops
moving.
j. CHECK-~ cursor aligns with the 11th graticule line
within 0.2 division.
k. Set the A SEC/DIV to 10 ns.
I. Rotate the
~
REF OR DL Y and the
~
controls to pre-
cisely superimpose the cursors near the 2nd graticule line.
m. CHECK-~t readout indicates a difference of
0.30 ns or less.
4-24
Over Any
4 Div 5 Div 6 Div
7 Div
8 Div 9 Div 10 Div
±0.09 ±0.10 ±0.10 ±0.11 ±0.12 ±0.12 ±0.13
Div Div Div Div Div Div Div
±0.11 ±0.12 ±0.13 ±0.14 ±0.16 ±0.17 ±0.18
Div Div Div Div
Div Div Div
1-5 1-6 1-7
1-8
1-9
1-10 1-11
2-6 2-7 2-8 2-9 2-10 2-11
3-7 3-8 3-9 3-10 3-11
4-8 4-9 4-10
4-11
5-9
5-10
5-11
6-10 6-11
7-11
n. Rotate the ~ REF OR DL Y and the ~ controls to pre-
cisely superimpose the cursors near the 10th graticule line.
o. CHECK-~t readout indicates a difference of 0.30 ns
or less.
p. Set:
HORIZONTAL
A SEC/DIV
B SEC/DIV
X10 MAG
TRIGGER
B TRIGGER MODE
Delta
~t
20 ns
10 ns (knob in)
Off
RUN AFT
DLY
On (Push ~t for
~t cursors)