Tektronix 3B5, Instruction Manual

Page: 123 / 187

Calibration —Type 3B5
Fig. 6-19. Typical CRT display showing correct registration. (A) MANUAL TIME/DIV switch set to .1
μ
s, (B) MANUAL TIME/DIV switch set
to 50ns, (C) Location or Registration adjustment (Time-Base Board).
19. Adjust 50-Nanosecond and 20-Nano-
second Timing
a. Set the MANUAL TIME/DIV switch to 10 μ s.
b. Move the start of the trace to the left vertical graticule
line with the POSITION control.
c. Set the time-mark generator for 50-nanosecond markers.
d. Set the MANUAL TIME/DIV switch to 50 ns.
e. Move the nearest marker to the first vertical graticule
line.
f. CHECK —CRT display for one marker each division
between the first and ninth graticule lines (see Fig. 6-20A).
g. ADJUST — 50 ns Cal adjustment, R508 (see Fig. 6-20B),
for one marker each division.
h. Set the time-mark generator for 20-nanosecond markers.
i. Set the MANUAL TIME/DIV switch to 20 ns.
j. Move the nearest marker to the first vertical graticule
line.
k. CHECK— CRT display for one marker each division
between the first and ninth graticule lines (see Fig. 6-20C).
l. ADJUST — 20 ns Cal adjustment, C507 (see Fig. 6-20B),
for one marker each division.
m. Repeat steps a through I and readjust if necessary.
n. Recheck step 18 and readjust if necessary.
o. INTERACTION— Check step 20.
20. Adjust 10-Nanosecond Timing
a. Set the MANUAL TIME/DIV switch to 10 ns.
b. CHECK —CRT display for one marker each two divisions
(see Fig. 6-21) with the fifth marker within ±0.24 division of
the ninth vertical graticule line (timing within ±3%). (If tim ­
ing error is greater than 5%, replace V544 and repeat steps
17 to 20.)
6-19