HP 8340B Manual page 35

4-5.
MAXIMUM
LEVELED OUTPUT POWER AND POWER ACCURACY
TEST (Cont'd)
NOTE
The
maximum leveled power indication may differ with
sweep mode and
sweep time.
To find the worst
case,
the maximum leveled power is
checked
in
continuous sweep
with auto sweep time (step
3),
single
sweep
with auto
sweep time (step 4), and single
sweep
with
a two
second sweep time (step
5).
4.
Press [SINGLE
SWEEP]
repeatedly and repeat
step 3.
5.
Press
[SWEEP TIME]
and enter
[2]
[sec]. Repeat step
3.
6.
Select the mode that gave the worst case maximum leveled
power
indication (lowest
ENTRY
DISPLAY
indication). Press
[M2]
and use the rotary knob to position the marker to the minimum
power
level
point on the oscilloscope trace (for
a
negative polarity crystal detector, this
is the
highest point on the display,
for
a
positive polarity detector, this
is the lowest point on the display).
Using the oscilloscope vertical position control, position the marker on
a
horizontal graticule
line.
Note the marker frequency. Press [MANUAL]
and enter the frequency noted for M2. Due to
SYTM
tracking, the
RF output
level at
a
single frequency
may be greater than in
a
swept mode. therefore,
if
the oscilloscope now indicates
a
higher
power
level than the swept response
(for
a positive
polarity detector, the trace moves down), press
[POWER LEVEL] and (using the rotary knob)
adjust the power level to return the dot on the oscilloscope to the horizontal
reference
line for the
minimum swept
power point.
7. Disconnect the 10
dB pad and
crystal
detector and connect the Power Sensor to the
DUT RF
output. Set the
Power Meter's calibration factor switch to include the frequency noted for
M2.
To
obtain the most accurate Power Meter reading, zero the Power Meter on the
range being used.
To zero the Power Meter, press the
Power Meter RANGE HOLD, press DUT [RF]
off, zero
the
Power Meter,
and press [RF]
on.
The Power Meter
indication should be equal to or greater than the maximum leveled
power
specification.
If the DUT does
not meet
its
maximum leveled
power
specification, refer to
SRD
Bias and
SYTM Tracking
adjustments
in
Section V.
8.
Press the[START FREQ] key
and enter the start frequency for the next band. Press the
[STOP
FREQUENCY]
key and enter the stop frequency for the next band. Repeat steps
3
through
7
until
all
frequency bands have been checked.
FLATNESS
9.
Flatness
is
measured
with the
RF output
level at 0
dBm. Flatness is primarily
a
function of the RF
path; therefore, the response will be essentially the
same
at
all
ALC
levels.
Although the ALC
accuracy
is
not specified separately, the ALC accuracy
is
typically
<0.15
dB
for
RF output
levels
from
-HO dBm
to
—9.95 dBm.
To
test
ALC accuracy,
step the
DUT's RF power
in 1 dB steps from
-HO to
-9.95
dBm
(note, for
instruments with front
panel RF output,
that as the
power steps from
-9.95
to -10
dBm, the RF
attenuator is
set to 10 dB and the
ALC
is
set to
0
dBm).
If
the
power meter
indication
is
>0
15 dB
from the ENTRY DISPLAY indication,
refer to the ALC adjustments
in Section
V
(in the Service
Manual).
HP 8340B/41B
Performance Tests
4-29