14.
Reduce
the
video
bandwidth.
As
the
video
bandwidth
is
reduced,
the
broadband
signal
amplitude
will
decrease
while
the
narrowband
signal
amplitude
remains
unc
hanged.
Con
tinue
to
reduce
the
video
bandwidth
un
til
the
trace
b ecomes
smo
othed
and
stops
c
hanging.
Av
eraging
o ccurs
when
the
video
bandwidth
is
smaller
than
the
low
est
pulse
rep etition
frequency
(PRF)
of
the
signal
b eing
measured.
15.
Press
4
PEAK
SEARCH
5
on
the
sp ectrum
analyzer
and
read
the
marker
amplitude
on
the
display
.
Refer
to
Figure
4-14.
Figure
4-14.
Av
erage
Measurement
CE03
(MIL-STD)
Measurement
The
MIL-STD
461
conducted
emission
test
v
aries
considerably
from
commercial
conducted
tests
in
terms
of
frequency
range,
test
setup,
transducer,
and
pro cedures.
Military
conducted
tests
are
p erformed
in
a
shielded
enclosure
on
a
test
b enc
h
with
a
copp er
or
brass
ground
plane.
The
ground
plane
usually
is
b onded
directly
to
the
w
all
of
the
shielded
enclosure.
A
ma
jor
goal
of
the
test
setup
is
to
isolate
the
EMI
receiv
er
and
tested
device
from
emissions
caused
b
y
the
p o
w
er
mains
serving
the
enclosure.
Isolation
b et
w
een
the
receiv
er
and
test
sample
is
done
b
y
using
separate
phases
of
A
C
p o
w
er
for
eac
h,
and
b
y
using
an
isolation
transformer.
F
or
further
isolation
the
receiv
er
may
b e
housed
in
a
shielded
an
tero
om
area
adjacen
t
to
the
test
sample
ro
om.
The
10
f
feedthrough
capacitors
pro
vide
go
o d
isolation
at
high
frequencies,
but
are
less
eective
in
the
low
frequency
range
to
10
kHz.
See
Figure
4-15.
HP
8572A
EMI
Receiv
er
User's
Guide
Making
Typical
Measurements
4-23
