HP 8340B Manual page 302

5-16.
LEVELED RF OUTPUT ADJUSTMENTS (Cont'd)
HIGHEST
PEAK ADJUSTED
FOR MINIMUM
HEIGHT--^^
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A
Figure 5-54.
Oscilloscope Display
at A26TP3 MOD LVL
with
no
Squegging
Q.
On the DUT, press
[INSTR PRESET] [SHIFT] [CF]
and enter [2] [0] [0]
[MHz]
for
a
CW
step size
of 200 MHz. Press [SWEEP TIME] [5] [0] [msec]. Press [SHIFT] [PWR SWP] to decouple
the RF
attenuator and ALC, and enter [•]
[2] [0] [dBm]. Press [PWR SWP] [4] [0] [dBm]
and
[AM]
to turn
the
AM
on. Press
[CW] [8] [GHz].
This puts the DUT
in
power sweep
from —20 to
+20 dB at any
frequency selected.
Save
this instrument state by pressing
[SAVE]
[1].
9.
Preset A24R1 (OFF A) (Figure 5-53), A24R2 (OFF
B),
A24R5 (X2C), A24R8 (X3C), and A24R11
(X4C) controls
fully
counter-clockwise.
10.
Set
the oscilloscope as follows:
DISPLAY
GHANA
CHANB
...............
CHOP
0.05 V/Div DC COUPLED
0.05
V/Div DC COUPLED
The oscilloscope display should look similar to Figure 5-55.
LEVELED POWER SRD BIAS
ADJUSTMENT
11.
Adjust A24R1 (OFF A)
for optimum display as shown in
Figure 5-55, Waveforms
A, B,
and C.
12.
On the
DUT, press
[CW] [1] [3] [GHz]. Adjust
A24R2 (OFF B)
for optimum trace as shown in
Figure 5-55,
Waveforms A, B, and C.
13.
On the
DUT, press [CW] [1] [0] [GHz].
Adjust
A24R5 (X2C)
to
minimize the
MOD LEVEL
voltage
(Channel A)
at
the start of the power sweep and keep the
MOD LEVEL power sweep
trace straight
with no
step or bows as
it
sweep
up (see Figure
5-55, Waveforms
D
and E).
Adjustments
HP 8340B/41B