Tektronix 2230, Service Manual

Page: 170 / 483

Adjustment Procedure— 2230 Service
c. ADJUST—A High Speed Timing (C703) for 1 time
marker per division over the center 8 divisions.
d. Set:
HORIZONTAL MODE B
A SEC/DIV
2
its
B SEC/DIV 1
f i S
e. ADJUST— B High Speed Timing (C713) for 1 time
marker per division over the center 8 divisions.
10. A djust 5 ns Tim ing and L in ea rity
(C775 and C785)
a. Set:
CH 1 VOLTS/DIV 0.2 V
Horizontal POSITION Midrange
HORIZONTAL MODE ’ A
A SEC/DIV 0.05 fiS
X I0 Magnifier
On (knob out)
b. Select 10 ns time markers from the time-mark
generator.
c. Align the time markers with the vertical graticule
lines using the Horizontal POSITION control.
d. ADJUST—5 ns Timing (C775 and C785 alternately)
for one time marker every 2 divisions over the center 8
divisions of the magnified sweep.
e. CHECK—Time markers between the 2nd and 4th
vertical graticule lines should be aligned within 0.05 divi­
sion. If not, a slight compromise between timing and
linearity should be made by readjusting the 5 ns Timing
capacitors (C775 and C785).
c. Adjust the A TRIGGER LEVEL control for a stable,
triggered display.
d. Use the Horizontal POSITION control to align the
2nd time marker with the 2nd vertical graticule line.
e. CHECK— Timing accuracy is within 2% (0.16 divi­
sion at the 10th vertical graticule line), and linearity is
within 5% (0.1 division over any 2 of the center 8
divisions).
NOTE
For checking the timing accuracy of the A SEC/DiV
switch settings from 50 ms to 0.5 s, watch the time
marker tips only at the 2nd and 10th vertical grati­
cule lines while adjusting the Horizontal POSITION
control.
f. Repeat parts c through e for the remaining A
SEC/DIV and time-mark generator setting combinations
shown in Table 5-7 under the "Normal (X I)" column.
g. Set:
A SEC/DIV 0.05
ns
X I0 Magnifier On (knob out)
h. Select 10 ns time markers from the time-mark
generator.
i. Use the Horizontal POSITION control to align the 1st
time marker that is 25 ns beyond the start of the sweep
with the 2nd vertical graticule line.
j. CHECK— Timing accuracy is within 3% (0.24 division
at the 10th vertical graticule line), and linearity is within 5%
(0.1 division over any 2 of the center 8 divisions). Exclude
any portion of the sweep past the 100th magnified
division.
11. Check Tim ing A ccu racy and L in ea rity
a. Set:
k. Repeat parts i and j for the remaining A SEC/DIV
and time-mark generator setting combinations shown in
Table 5-7 under the "X I0 Magnified” column.
CH 1 VOLTS/DIV 0.5 V
X I0 Magnifier Off (knob in)
b. Select 50 ns time markers from the time-marker
generator.
I. Set:
HORIZONTAL MODE
A SEC/DIV
B SEC/DIV
X I0 Magnifier
B
0.1
its
0.05
fis
Off (knob in)
5-22