Controlling
the
A
ttenuators.
Set
the
step
attenuators
as
follows.
Press
4
STIMULUS
MENU
5
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
POWER
MENU
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
ATTENUATOR
PORT:
1
or
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
ATTENUATOR
PORT:
2
.
Use
the
knob,
STEP
k
eys,
or
n
umeric
en
try
to
set
the
attenuator
from
0
dB
to
90
dB
in
10
dB
steps.
F
amiliarize
y
ourself
with
op eration
of
the
step
attenuators
b
y
measuring
the
user
parameters.
Measure
User
P
arameters
and
Set
A
ttenuators.
In
order
to
maintain
sp ecied
p erformance,
the
IF
signal
lev
els
are
less
than
010
dBm
as
measured
b
y
the
user
parameters.
Connect
an
appropriate
device
at
P
ort
1
or
P
ort
2
for
eac
h
measuremen
t,
turn
on
a
measuremen
t
marker,
then
measure
the
user
parameters
in
order
to
v
erify
the
IF
signal
lev
els
as
follo ws.
1.
Press
4
P
ARAMETER
MENU
5
NNNNNNNNNNNNNNNNNNNNNNNNNNNNN
USER
1
a1
and
observ
e
the
IF
signal
lev
el
in
the
LOG
MA
G
format.
2.
Press
NNNNNNNNNNNNNNNNNNNNNNNNNNNNN
USER
4
b1
and
observ
e
the
IF
signal
lev
el.
If
either
a1
or
b1
is
greater
than
010
dBm
at
an
y
p oint
in
the
trace,
increase
the
A
TTENUA
TOR
POR
T:
1
v
alue.
3.
Press
NNNNNNNNNNNNNNNNNNNNNNNNNNNNN
USER
3
a2
.
4.
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
REDEFINE
PARAMETER
NNNNNNNNNNNNNNNNN
DRIVE
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
DRIVE:
PORT
2
.
Observ
e
the
IF
signal
lev
el.
5.
Press
NNNNNNNNNNNNNNNNNNNNNNNNNNNNN
USER
2
b2
and
observ
e
the
IF
signal
lev
el.
This
sho
ws
the
lev
el
with
the
signal
applied
to
P
ort
1.
If
either
a2
or
b2
is
greater
than
010
dBm
at
an
y
p oint
in
the
trace,
increase
the
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
ATTENUATOR
PORT:
2
v
alue.
In
some
applications
it
may
b e
necessary
to
measure
the
signal
at
b2
with
the
signal
applied
to
P
ort
2.
F
or
this
measuremen
t:
6.
Press
NNNNNNNNNNNNNNNNNNNNNNNNNNNNN
USER
2
b2
.
7.
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
REDEFINE
PARAMETER
NNNNNNNNNNNNNNNNN
DRIVE
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
DRIVE:
PORT
2
.
Observ
e
the
IF
signal
lev
el.
Before
calibration,
measure
these
user
parameters
with
the
calibration
standards,
then
with
the
device
under
test
connected
and
op erating.
Generally
,
set
the
attenuators
to
obtain
the
maximum
p ossible
mixer
input
signal
lev
el
(less
than
010
dBm)
with
the
device
connected
and
op erating.
This
will
pro
vide
the
b est
signal-to-noise
ratio
for
the
measuremen
t.
Then
remov
e
the
device
and
p erform
measuremen
t
calibration.
F
or
b est
accuracy
,
do
not
c
hange
either
attenuator
b et
w
een
calibration
and
measuremen
t.
Changing
Signal
P
ath
After
Calibration
If
an
y
attenuator
or
other
external
equipmen
t
is
c
hanged
after
calibration,
the
measuremen
t
results
cannot
b e
sp ecied
except
b
y
y
our
o
wn
estimation
of
the
error
con
tribution
of
the
c
hange.
F
or
example,
when
the
p ort
attenuation
is
c
hanged
with
correction
On,
the
CAUTION:
CORRECTION
MAY
BE
INVALID
is
display
ed.
The
op erator
m
ust
judge
whether
the
error
is
tolerable
in
the
particular
application
and
ho
w
to
comp ensate
for
the
c
hange.
The
only
reason
to
c
hange
the
in
ternal
attenuators
or
external
equipmen
t
b et
w
een
calibration
and
measuremen
t
is
to
maximize
the
lev
els
under
b oth
conditions,
th
us
minimizing
uncertain
t
y
due
to
noise.
Many
factors
will
en
ter
in
to
the
decision
of
whether
it
is
more
Operation
3-33
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