Purp
ose
This
test
measures
reference
lev
el
switching
uncertain
t
y
.
Note
Y
ou
m
ust
complete
this
test
b efore
y
ou
p erform
an
y
amplitude
accuracy
test.
Description
\Reference
Lev
el
Switching
Uncertain
t
y"
relies
on
the
attenuator
accuracy
of
the
HP
3335A
syn
thesizer/level
generator.
Although
Reference
Lev
el
Switching
Uncertain
t
y
is
not
directly
sp ecied
for
the
HP
8572A
microw
a
v
e
EMI
receiv
er,
it
is
one
of
the
con
tributors
to
absolute
amplitude
accuracy
.
The
unit
under
test
is
set
for
a
reference
lev
el
of
+13
dBm,
and
a
resolution
bandwidth
or
QP
A
(CISPR)
bandwidth
to
b e
tested.
The
lev
el-generator
amplitude
is
adjusted
to
set
the
signal
2
dB
b elow
reference
lev
el.
The
dierence
b et
w
een
the
lev
el
generator
and
marker
amplitudes
establishes
a
reference
error
at
this
p oint.
The
lev
el
generator
and
EMI
receiv
er
system
reference
lev
el
are
stepp ed
do
wn
in
4
dB
incremen
ts
un
til
the
signal
is
057
dBm
or
10
dB
ab o
v
e
the
display
ed
a
v
erage
noise,
whic
h
ev
er
is
higher.
The
amplitude
dierence
b et
w
een
the
lev
el
generator
and
the
display
ed
trace
a
v
erage
is
measured
at
eac
h
lev
el
generator
step.
The
dierence
b et
w
een
the
amplitude
error
at
eac
h
lev
el
generator
step
and
the
reference
error
is
the
lev
el
switching
uncertain
t
y
of
the
EMI
receiv
er
system .
T
est
Settings
F
unction
Settings
RF
FREQ
30
MHz
RFPS
(atten)
43
dB
EMI
receiv
er
system
(input)
receiv
er
INPUT
1
SA
(atten)
10
dB
QP
A
lter
200
Hz,
9
kHz,
120
kHz
RES
BW
3
kHz,
10
kHz,
100
kHz,
1
MHz
Scale
Log
1
dB
3-10
T
est
Descriptions
HP
8572A
EMI
Receiv
er
User's
Guide