
3. Preliminary Display Adjustments (SN 3001A and Below)
Note
The pulse/function generator output must be terminated with 50
ohms. Use a BNC tee, a
509
termination, and a BNC female to SMB
female
adapter. Install the
500
termination as close to the Display
Adjustment PC Board as possible.
26. Set the pulse/function generator controls as follows:
MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NORM
Waveform
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..pulse
Frequency (FRQ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.200
kHz
Width (WID)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 ns
Amplitude (AMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.4.OOV
Offset (OFS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.2.OOV
27. Set the spectrum analyzer front-panel INTENSITY control fully
clockwise. Adjust the oscilloscope trigger level for a stable display.
Note the display on the oscilloscope. The pulse should be
>55V
peak-to-peak.
28. Set the oscilloscope controls as follows:
Press
m):
Channel 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . on
amplitude scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...8.0
V/div
Press
m).
29. Adjust
AlA4R7
X POS and
AlA5R7
Y POS to either extreme to
position the CRT beam off-screen (to prevent possible damage to
the CRT phosphor). If it is not sealed, adjust AlA2R5 INT GAIN
fully clockwise.
30. Adjust the spectrum analyzer front-panel INTENSITY control for
50 V peak-to-peak (6.25 divisions) as indicated
on
the oscilloscope.
See Figure 3-22.
.
.._...............
_...................
,..
,..
_._
.
..-.....................................................~ .._.............
.I.
.:.
i
.._.............................-...........~......~...........................................
I
.._.............................................................................
“..
,,,,,,.,,,,,,,..,.
*
-125.000
ns
125.000 “s
37s.000
ns
50.0
ns/div
1
8.00
V/div
,rrset:
45.00 v
10.00
:
I dc
1
f
50.00 v
Figure 3-22.
5OV,.,
Signal
31. Adjust
AlA2R22
HF GAIN and
AlA2ClO
for minimum overshoot
on rise and minimum rise and fall times of the pulse waveform.
3-54 Adjustments
Commentaires sur ces manuels