Tektronix CURVE-TRACER 576 Instruction Manual page 150

Performance Check/Calibration-Type 576
e. Set the DISPLAY OFFSET Selector switch to HORIZ
X10.
f. Reposition the spot to the intersection of the tenth
horizontal and center vertical graticule line.
g. Set the LEFT-OFF-RIGHT switch to OFF and replace
the shorting strap with a 18 kS"l resistor. Set the LEFT-
OFF-RIGHT switch to RIGHT.
h. Check for the spot centered horizontally.
i. ADJUST -R243, OUTPUT Z adjustment on the STEP
GEN circuit board, (see Fig. 5-7) if the spot is not centered.
j. Exchange the 18 kS"l resistor for the shorting strap and
check for no movement of the spot between the two step
generator loads.
k. Disconnect the resistors and shorting strap from the
Standard Test Fixture.
I.
(If doing Adjust steps only go to step 32.)
Control Settings (Partial List)
Type 576
VERTICAL
DISPLAY OFFSET Selector
CENTERLINE VALUE
HORIZONTAL
AMPLITUDE
OFFSET MULT
STEP FAMILY
MAX PEAK POWER WATTS
POLARITY
2A
HORIZ X10
0
1 V BASE
1
v
10.00
REP
220
+(NPN)
Test Oscilloscope
Time/Cm
Triggering
Volts/Cm
Input Coupling
2 ms
Trig,-, DC, lnt
2
DC
24. Check Step Generator and Offset Multiplier
Accuracy
a. Set the Type 576 and test oscilloscope controls as
shown in the list of Initial Control Settings except as shown
above.
5-22
b. Press the ZERO button and position the spot onto the
center horizontal graticule line.
c. Release the ZERO button.
d. CHECK FOR-Spot on the center horizontal graticule
line ±0.1 division (1% of 1 volt).
NOTE
The Type 576 vertical, horizontal, and display offset
must be calibrated to perform the following checks.
e. Turn the CENTERLINE VALUE switch throughout
its range, two positions at a time.
f. CHECK FOR-A spot in the same position horizon-
tally on the CRT each time the CENTERLINE VALUE
switch is switched two positions ±0.5 division (5% of 1
volt).
g. Set the CENTERLINE VALUE switch to 10.
h. CHECK FOR-Spot on the center vertical line ±2
divisions (±2% of total output).
i. Press the AID OFFSET button.
j, CHECK FOR-Spot on the center vertical line ±2 divi-
sions ( ±2%).
k. Turn the OFFSET MU L T control counterclockwise
throughout its range. For each complete revolution of the
OFFSET MULT control, turn the CENTERLINE VALUE
switch clockwise two positions.
I. CHECK FOR-Continuous decrease in zero step volt-
age level.
m. Set the Type 576 OFFSET MULT control to 10.00
and press the OFFSET OPPOSE button.
n. CHECK FOR-Spot on center vertical graticule line
±2 divisions (±2%).
o. Set the following Type 576 controls to:
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