HP 8340B Manual page 33

4-5.
MAXIMUM
LEVELED OUTPUT POWER AND POWER ACCURACY
TEST
(Cont'd)
Description
MAXIMUM
LEVELED POWER
For maximum leveled power,
a
crystal detector and an oscilloscope are used
to
monitor the swept
response.
The DUT
is
set
to
sweep
a given frequency band.
The power
level is increased until
the
DUT's UNLEVELED
indicator
comes
on, then decreased until
the
UNLEVELED indicator just goes
out.
The maximum leveled power may
differ with
sweep mode and
sweep time.
To find the worst case,
the maximum leveled power is checked in
three modes: single sweep
with
auto sweep
time, single
sweep
with
a
two second sweep
time, and continuous
sweep. The worst case mode
is
selected, and
a
frequency marker
is
positioned at the minimum power point on the
swept display. The DUT
is
set to
CW
at the marker frequency and the power
is
measured using
a
power
meter.
The power meter
indication should be
greater
than or equal to the maximum leveled
power
specification. This
pro¬
cedure
is
repeated for each frequency band.
FLATNESS
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.
However, the response will
most
likely change when the RF Attenuator
is
stepped to
a
different attenuation
level.
A
power meter
is
used to measure the RF signal level. An
oscilloscope, connected to the power meter
recorder output,
is used
to find the frequencies
where the maximum and minimum points
of the
response occur. The
DUT
is
set to
a
slow sweep to allow the power meter to respond
to any power
variations.
A
marker
is positioned at the maximum and minimum points on the oscilloscope display.
The DUT
is
then set to
CW
at each of the marker frequencies and the
power indications
are recorded.
The maximum power level minus the minimum
power
level
should be within the flatness specification.
ACCURACY
The absolute power
level at
the maximum and minimum points should be within the
accuracy
specifi¬
cation.
Two different Power Sensors may be
required to cover the complete frequency range. The HP 8481A
Power Sensor is
used from 10
MHz to
50
MHz
and the HP 8485A Power Sensor
is
used for the other
frequency bands covering 50 MHz
to maximum output frequency
of the
DUT, The 8485A Power
Sensor can be used down
to 10
MHz,
but if
a
minimum or maximum that is close to the test limits
occurs
in
this
frequency range, the 8481A Power Sensor should
be used.
Equipment
Oscilloscope
...................................................
HP 1741A
Attenuator
................................. ...........
HP 8493C Opt. 010
Crystal Detector
................................................
HP 8473C
Power Meter
..........................................
HP 436A Option 022
Power Sensor
.................................................
HP 8481A
Power Sensor
................................................
HP 8485A
Adapters
APC
3.5
(f)
to
APC 3.5 (f)
................................
HP P/N
5061-5311
(1
required
if DUT
is
HP 8340B)
TYPE N (m) to APC 3.5 (f)
...............................
HP P/N 1250-1744
(1 required
if
DUT
is
HP 8341 B)
SMC (f)
to BNC (f)
.....................................
HP P/N 1250-0832
HP 8340B/41B
Performance Tests 4-27