Tektronix CURVE-TRACER 576 Instruction Manual page 168

Adjustment-Type 576
6. Adjust Balance of Vertical Display Amplifier
a. Set the DISPLAY OFFSET Selector switch to VERT
X 10 and position the spot to the center of the graticule
using the FINE POSITION controls.
b. Set the DISPLAY OFFSET Selector switch to VERT
X1.
c. Check for the spot on the horizontal centerline of the
CRT graticule.
d. ADJUST -R581, VERT CENT adjustment, on the
DISPLAY AMP circuit board (see Fig. 1-5) if the spot is not
centered.
e. Repeat parts a through d until no movement of the
spot occurs between the two settings of the DISPLAY
OFFSET Selector switch.
f. Set the following Type 576 controls to:
DISPLAY OFFSET
Selector
VERTICAL
VERT X10
1 A
g. Check for the spot vertically centered on the CRT
graticule.
h. ADJUST-R550, 1'S BAL adjustment, on the
DISPLAY AMP circuit board (see Fig. 1-5) if the spot is not
centered.
i. Set the VERTICAL switch to 2 A.
j. Check for the spot vertically centered on the CRT
graticule.
k. ADJUST -R545, 2'S BAL adjustment, on the DIS-
PLAY AMP circuit board (see Fig. 1-5) if the spot is not
centered.
I. Set the VERTICAL switch to .5 A and recheck the
adjustments made in parts a through k.
7. Adjust Horizontal and Vertical CRT Gain
a. Set the DISPLAY OFFSET Selector switch to NORM
(OFF) and the POLARITY switch to +(NPN).
A-10
b. Position the spot to the zero horizontal and vertical
CRT graticule lines (see Fig. 1-4) using the FINE
POSITION controls.
c. Set the POLARITY switch to -(PNP).
d. Check for the spot on the tenth horizontal and ver-
tical CRT graticule lines ±0.1 division both horizontally and
vertically.
e. ADJUST -R692, HORIZ OUTPUT GAIN adjust-
ment, and R592, VERT OUTPUT GAIN adjustment, on a
chassis bracket on the right of the instrument (see Fig. 1-5)
to remove one half the error noted in part d.
f. Set the POLARITY switch to + (NPN) and repeat
steps b through e until 10 divisions of horizontal and
vertical deflection are obtained between the +(NPN) and
-(PNP) positions of the POLARITY switch.
g. Set the POLARITY switch to AC.
8. Adjust Horizontal and Vertical Magnifier Gains
a. Set the DISPLAY OFFSET Selector switch to
HO R I Z X 1 0 and position the spot on the center vertical
graticule line with the horizontal FINE POSITION control.
b. Switch the CENTERLINE VALUE switch between
the 4.5 and the 5.5 positions.
c. Check for the spot deflected 10 divisions horizon-
tally, when the CENTERLINE VALUE switch is switched
from 4.5 to 5.5.
d. ADJUST -R673, HORIZ MAG GAIN adjustment, on
the DISPLAY AMP circuit board (see Fig. 1-5) if the spot
deflection is not correct.
e. Set the DISPLAY OFFSET Selector switch to VERT
X10 and the CENTERLINE VALUE switch to 5.
f. Position the spot on the center horizontal graticule
line with the vertical FINE POSITION control.
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g. Switch the CENTERLINE VALUE switch between
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the 4.5 and 5.5 positions.
ADD AUG 1984
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