HP 8340B Manual page 292

5-15.
ALC ADJUSTMENTS (Cont'd)
15.
Connect the equipment as shown
in
Figure 5-47. Calibrate and zero the power meter. Allow one
hour warmup time. Connect the power sensor to the DUT's RF output. Press [INSTR PRESET]
on
the DUT. Press
[CW]
and enter [4] [.] [5] [GHz]. Press the [RF] key to turn the
RF OFF
and
zero
the
power
meter.
To ensure that
the power meter
is
properly
zeroed, select
"WATT"
mode,
and
press
ZERO
until the power meter indicates ^0.02 on the most sensitive range.
Press [RF] to
turn
the RF
ON.
Press
[PEAK]
to turn peaking on. Press
[SHIFT] [PWR SWP]
to
decouple the RF
attenuator and ALC. Enter
[0] [dBm].
If the display
does not indicate
ATTEN=0 dB, press STEP
keys as necessary to select
0
dB attenuation.
POWER
METER
OUT
0
ADAPTER
INPUT
APC-3.5(f)
to N(m)
(83418 ONLY)
POWER SENSOR
^—C=[]—^
^ t
^^<1 B
^^
ADAPTER
APC-3.5(f)
to
APC-3.5(f)
(8340B ONLY)
Figure 5-47.
A1C
Adjustment Test Setup
NOTE
When the power level
is changed significantly,
it
may take as long as one
minute for the
power meter
indication to be accurate. After making
a
power level change, wait until the power meter indication stabilizes
before making any adjustments.
16.
Refer
to Table
5-8 below, enter
the appropriate
DUT power
level
(ALC
level) and
check the power
meter indication. Check the
indication at each
power
level and note the amount of error before
making any adjustments.
If necessary, adjust the appropriate controls shown
in
the table to adjust
the power level to be within the test limit
shown.
Adjustments are iterative. Adjust
in
the following order:
0
dBm,
-10
dBm,
-20
dBm,
-10
dBm,
0
dBm,
+10
dBm,
+18
dBm, and
+10
dBm.
When selecting
a new power level, press
[SHIFT] [PWR
SWP] [desired power level] [dBm].
See Figure 5-48 for more information that may help to reduce the number of iterations required.
For example,
if
the
+18
dBm indication
is 0.1
dB low
(+17.9 dBm), adjust for
0.05 dB high
(+18.05dBm).
Then when the +10isadjustedto +10dBm, the
+18
will
move close to the correct
level.
HP 8340B/41B
Adjustments