HP 3585A Service Manual page 126

Adjustments
H i g h Voltage Sticker
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q. Remove the high voltage probe from the test point .
r . Using the front panel focus control, focus the 3585A CRT display. If the round dot on
the instrument 's CRT can be focused with the focus control between the 1 0 o ' clock and 2
o ' clock positions, proceed at step v, if not , continue with next step .
s . Set the focus control and astigmatism control to the 1 2 o ' clock position .
t . Adjust the focus limit pot (A65RI 3) for the smallest , most symmetrical round dot on
the 3585A CRT .
u . Turn the 3585A power off. Replace the high voltage cover and the instruments bottom
cover . Set the 3585A back in a normal upright position .
v . Remove the shorts from the "Xin " and "Yin " inputs on the A67 board . Reconnect
the proper cables to these inputs .
w. Move the test jumper A63 J3 to the "T" position (see Figure 5-8) . Turn 3585A power
on .
x. Set the oscilloscope for :
y. Connect a 10: 1 scope probe to A63TP l . Verify that the signal amplitude is s O. 7V to
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3 . 5V minimum .
z . Verify that the rise and fall time of the waveform is between 1 0 and 70 nsec between the
1 0 % and 900/0 points (see Figure 5-9).
5 - 1 2
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- R 2 -
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Figure 5·7. High Voltage Board (AB5)
Vertical Scale . . . . . . . . . . . . . . . . 0.2V/Div (DC coupled)
Horizontal Scale . . . . . . . . . . . . . . . . . . . . . . 0.05,.,sec/Div
C§X
4 kV Test Point
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R7
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- R8-
-R6-
- CR 3-
- R 3 -
- C4 -
Model 3585A
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