Purp
ose
This
test
measures
the
bandwidth
accuracy
of
the
EMI
receiv
er
system.
Description
Bandwidth
Accuracy
measures
the
6
dB
bandwidth
and
60
dB
bandwidth
of
the
10
Hz
to
3
MHz
resolution
bandwidths
in
the
receiv
ers.
The
6
dB
bandwidth
accuracy
is
sp ecied
only
for
the
10
Hz
to
300
Hz
resolution
bandwidths.
The
impulse
bandwidth
is
sp ecied
for
the
wider
resolution
bandwidths.
Ho
w
ev
er,
the
selectivit y
is
sp ecied
for
all
bandwidths,
so
the
6
dB
bandwidth
is
measured
for
all
bandwidths.
Resolution
bandwidth
settings
of
10
Hz,
30
Hz,
100
Hz,
and
300
Hz
are
sp ecied
as
6
dB
bandwidths
and
are
tested
separately
.
In
the
rst
setup,
the
1
kHz
to
3
MHz
impulse
bandwidths
are
measured
in
the
EMI
receiv
er
system .
The
receiv
er's
amplitude
resp onse
to
the
same
pulsed-RF
signal
is
measured
b oth
in
pulse
mo
de
and
in
line
mo
de.
Amplitude
dierence
and
pulse
rep etition
frequency
are
measured
b
y
a
frequency
coun
ter.
A
syn
thesizer
is
used
to
correct
IF
gain,
log
delity
,
and
bandwidth
switching
errors
in
the
amplitude
resp onse.
Then,
the
pulse
generator
output
is
connected
directly
to
the
receiv
er's
input.
The
RF
preselector
m
ust
b e
put
in
b
ypass
mo
de
when
testing
impulse
bandwidths
of
300
kHz
to
3
MHz.
If
this
is
not
done,
the
bandwidth
of
the
RF
preselector
will
predominate,
resulting
in
a
narrow
er
measured
impulse
bandwidth.
These
wider
bandwidths
are
not
used
under
30
MHz,
where
the
bandwidth
of
the
RF
preselector
is
wide
enough
not
to
aect
the
measuremen
t.
The
amplitude
resp onse
corrections
are
then
made.
The
syn
thesizer
frequency
is
set
to
the
original
test
frequency
.
The
EMI
receiv
er
system
is
set
as
it
w
as
for
the
line-mo
de
measuremen
t
and
the
syn
thesizer
amplitude
is
adjusted
to
match
the
amplitude
measured
previously
.
The
EMI
receiv
er
system
is
then
set
as
it
w
as
for
the
pulse-mo de
measuremen
t
and
the
syn
thesizer
amplitude
is
adjusted
to
match
the
amplitude
measured
previously
.
These
t
w
o
syn
thesizer
amplitude
settings
are
recorded
and
used
in
the
calculation
of
the
impulse
bandwidth.
HP
8572A
EMI
Receiv
er
User's
Guide
T
est
Descriptions
3-27