5.
Set
the
span
by
pressing:
4
SP
AN
5
NNNNNNNNNNNNNNNNNNNNNNNNNNNNN
SPAN
ZOOM
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
500
4
kHz
5
Notice
the
signal
has
remained
in
the
center
of
the
display
.
Note
If
the
signal
you
selected
drifts
too
quickly
for
the
receiver
to
keep
up
with,
increase
the
span.
6.
The
signal
frequency
drift
can
be
read
from
the
screen
if
both
the
marker
track
and
marker
delta
functions
are
active
.
Press:
4
MKR
5
N
NNNNNNNNNNNNNNNNNNNNNNNNN
MARKER
1
4
MARKER
FUNCTION
5
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
MK
TRACK
ON
OFF
ON
The
marker
readout
indicates
the
change
in
frequency
and
amplitude
as
the
signal
drifts
.
(See
Figure
6-9.)
Figure
6-9.
Using
Marker
Tracking
to
Track
an
Unstable
Signal
The
receiver
can
measure
the
short-term
and
long-term
stability
of
a
source
.
The
maximum
amplitude
level
and
the
frequency
drift
of
an
input
signal
trace
can
be
displayed
and
held
by
using
the
maximum-hold
function.
The
minimum
amplitude
level
can
be
displayed
by
using
minimum
hold
(available
for
trace
C
only).
Y
ou
can
use
the
maximum-hold
and
minimum-hold
functions
if,
for
example
,
you
want
to
determine
how
much
of
the
frequency
spectrum
an
FM
signal
occupies
.
6-14
Making
EMI
Diagnostic
Measurements
