R
IGOL
T
ECHNOLOGIES USA
I
NC
877-4-RIGOL-1 How-To
Guide
www.rigolna.com
So
in
this
case
every
20
dB
is
a
factor
of
10x
the
voltage.
Usually,
dB
is
used
in
terms
of
Watts
or
milliWatts
(dBm)
in
which
case
every
10
dB
is
a
factor
of
10x
the
power,
but
because
of
the
relationship
between
power
and
voltage
note
that
20
dB
is
a
factor
of
10
on
your
scopes
display.
The
horizontal
units
per
division
of
the
FFT
are
always
in
frequency.
The
above
screen
shot
shows
1.25
KHz
per
division.
In
this
display,
the
left
side
of
the
screen
is
always
at
DC
or
0
Hz.
Each
division
to
the
right
then
marks
the
set
value.
In
this
case
the
divisions
would
be
0
Hz,
1.25
KHz,
2.5
KHz,
3.75
KHz,
5
KHz,
and
so
on.
How
to
save
a
waveform's
FFT?
To
save
an
FFT
to
the
scope
or
a
USB
drive,
the
FFT
must
be
saved
as
a
reference
wave
“REF”
as
in
the
following
procedure:
Press
the
“REF”
button.
When
the
side
menu
appears,
set
the
source
to
be
the
FFT.
Then
use
the
“Save”
option
in
the
menu
to
save
locally
or
externally.
