HP 8340B Manual page 323

5-18.
PULSE ADJUSTMENTS (Cont'd)
17.
Set
up the pulse generator for
a
25 kHz, 5
Vpk (10 Vp-p), square wave.
18.
Set the
oscilloscope as follows:
DISPLAY
...................................................
CHANNEL A
CHAN
A
.................................................
.005 V/Div (AC)
CHAN
B
..............................................
2.0 V/Div (50 Ohm)
TRIGGER
.....................................................
CHAN B
TIME/Div
........................................................
5
usec
19.
On the HP 8340B (Option 006), press
[CW]
[1] [GHz] [POWER LEVEL] [5] [dBm] [SHIFT] [AM]
[SHIFT] [PULSE].
20. Adjust A26R7 (BAL) and A25R58 (BAL)
full
clockwise.
The oscilloscope display should look
sim¬
ilar to Figure
5-68, waveform
a.
21.
Adjust A25R58 (BAL)
for an oscilloscope display as shown
in
Figure
5-68, waveform
b.
22. Adjust A26R7 (BAL) for an oscilloscope display as shown
in
Figure
5-68, waveform
c.
SLOW PULSE MODULATION
FINE
ADJUSTMENT
23.
Connect the equipment
as
shown
in
Figure 5-69. Connect
the
mixer
directly to the local
oscillator's RF output to obtain the
maximum
LO drive to the mixer. Connect the
BNC tee directly
to
the
DUT's PULSE connector. Allow 30 minutes
for the instruments to
warm
up.
24.
Set the
oscilloscope as follows:
DISPLAY
...................................................
CHANNEL B
CHAN A
..............................................
0.1
V/Div,50 Ohms
CHAN B
...............................................
5
V/Div,50
Ohms
TRIGGER
.................................................
INT., CHAN
B
TIME/Div
........................................................
5
usec
25.
Set
up the pulse generator for
a
25 kHz (8
divisions on the oscilloscope),
5V peak
(10V
p-p) square
wave. The damage
level
for the DUTs
PULSE
input
is
+12V
-20V so do not overdrive the input.
26. On
the DUT, press [INSTR PRESET]
[CW] [2] [GHz] [POWER LEVEL] [0] [dBm] [SHIFT]
[PULSE].
NOTE
For best accuracy
in this test, the
LO drive to the mixer
should be
>
+4
dBm.
27. On the LO,
press [INSTR PRESET] [CW] [1] [.] [9] [5] [GHz] [POWER] [LEVEL] [1] [0] [dBm].
28. Press DISPLAY A
on the oscilloscope. Adjust A21 R30 (LSYM) so that the 50%
points on the
pulse
envelope cover four vertical graticules
on the
oscilloscope
(50% duty cycle).
29. On the DUT, press
[CW] [3] [GHz].
On the LO, press
[CW] [2] [.] [9] [5] [GHz].
Adjust
A21R29
(HSYM)
so that the
50%
points on the pulse envelope cover four vertical graticules on the
oscilloscope (50%
duty cycle).
5-126 Adiustments
HP 8340B/41B