Preselector
P
eaking
for
Receiv
er
INPUT
3
T
o
obtain
the
sp ecied
absolute
amplitude
accuracy
for
the
2
GHz
to
22
GHz
frequency
bands,
the
tracking
preselector
m
ust
b e
p eak
ed
for
eac
h
signal.
If
this
is
not
done,
display
ed
signals
ab o
v
e
2
GHz
are
likely
to
b e
display
ed
as
m
uc
h
as
5
dB
to
7
dB
low
er.
This
discrepancy
could
cause
amplitude
errors
of
00.7
to
01
dB,
whic
h
b ecomes
signicant
given
the
62
dB
amplitude
accuracy
sp ecication.
T
o
determine
the
true
amplitude
of
a
signal,
place
the
marker
on
the
p eak
of
the
signal
and
press
4
PRESEL
PEAK
5.
The
sp ectrum
analyzer
automatically
ne
tunes
its
preselector
lter,
using
a
digital-to-analog
con
v
erter
(DA
C),
for
maximum
signal
amplitude,
so
the
signal
is
not
attenuated
b
y
the
lter
skirts.
Use
the
factory-default
preselector
D
A
C
setting
of
32
(obtained
b
y
executing
4
SHIFT
5
4
PRESEL
PEAK
5)
for
b est
o
v
erall
frequency
resp onse
when
viewing
an
en
tire
sw
ept
frequency
band.
Because
the
relativ
e
tuning
of
the
preselector
lter
c
hanges
at
dieren
t
p oints
in
an
y
given
frequency
span,
the
optimum
preselector
p eak
D
A
C
v
alue
can
dier
b
y
sev
eral
D
A
C
n
um
b ers,
for
dieren
t
frequencies
in
a
given
frequency
span,
causing
as
m
uc
h
as
1
dB
amplitude
error.
T
o
a
v
oid
this,
execute
4
PRESEL
PEAK
5
at
eac
h
frequency
of
in
terest.
T
able
1-1.
Frequency
Bands
F
requency
Band
F
requency
Range
n
YTO
F
requency
Range
0
A
1
0.0{2.5
GHz
1
3.62{6.12
GHz
1
B
2.0{5.8
GHz
1
2.32{6.12
GHz
2
C
5.8{12.5
GHz
2
2.74{6.09
GHz
3
D
12.5{18.6
GHz
3
4.06{6.09
GHz
4
E
18.6{22.0
GHz
4
4.57{5.42
GHz
1
Lo
w
Band
(preselector
p
eaking
is
not
required).
HP
8572A
EMI
Receiv
er
User's
Guide
Calibrating
Y
our
Receiv
er
1-7