Tektronix 422, Instruction Manual

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Performance Check/Calibration—Type 422 AC-DC
e. CHECK—CRT display fo r four-division maximum
spacing between markers (indicates adequate range fo r con­
tinuously variable sweep rates between the calibrated
steps).
f. Return the V A R IA B LE T IM E /D IV control to CAL.
47. Adjust 5 Microsecond Timing
PERFORMANCE CHECK ONLY
Complete normal and magnified accuracy of the
T IM E /D IV switch is checked in Tables 5-5 and 5-6.
Therefore delete steps 47 through 49 fo r a perfor­
mance check only and proceed to step 50.
a. Set the time-mark generator fo r five-microsecond
markers.
b. Set the T IM E /D IV switch to 5 /us.
c. CHECK—CRT display fo r one marker each division
between the second and tenth vertical lines o f the graticule.
Tenth marker must be w ithin 0.24 division (within 3%) of
the tenth vertical line w ith the second marker positioned
exactly to the second vertical line.
d. ADJUST—C440A (see Fig. 5-26) fo r one marker each
division (use low-capacitance screwdriver).
Fig. 5-26. Location of C440A (top).
48. Adjust 0.5 Microsecond Timing
a. Set the time-mark generator for 0.5 microsecond
markers.
b. Set the T IM E /D IV switch to .5 (is.
c. CHECK—CRT display fo r one marker each division
between the second and tenth vertical lines o f the graticule.
Tenth marker must be w ith in 0.24 division (within 3%) of
the tenth vertical line w ith the second marker positioned
exactly to the second vertical line.
Fig. 5-27. Location of high-speed timing adjustments (Horizontal
Amplifier board).
d. ADJUST—C537 (see Fig 5-27) fo r one marker each
division (use low-capacitance screwdriver).
e. Set the T IM E /D IV switch to 1 /us.
f. CHECK—CRT display fo r tw o markers each division
between the second and tenth vertical lines o f the graticule.
If necessary, compromise the setting o f C537 fo r minimum
tim ing error in the .5 /us and 1 /us positions.
49. Adjust 0.5 Microsecond X I 0 Magnified Timing
a. Set the time-mark generator fo r 50-nanosecond mar­
kers.
b. Change the follow ing control settings:
T IM E /D IV .5 [is
X 1 0M A G Pulled out
c. Position the first marker of the total magnified sweep
length to the second vertical line o f the graticule.
d. CHECK—CRT display fo r one marker each division
between the second and tenth vertical lines o f the graticule.
e. ADJUST—C511 (see Fig. 5-27) fo r one marker each
division (use low-capacitance screwdriver).
f. Adjust the horizontal POSITION control so the cen­
ter o f the total magnified sweep is displayed. If necessary,
tem porarily push in the X I 0 MAG switch to obtain the
correct position.
g. CHECK—CRT display fo r one marker each divison
between the second and tenth vertical lines o f the graticule
( X I 0 MAG switch pulled out).
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