HP 8753D - Page 304

The
default group
delay aperture
is the
frequency
span
divided
by
the
number
of
points
across
the
display.
T
o
set
the
aperture
to
a
dierent
value
,
turn
on smoothing
in the
average menu,
and
vary the
smoothing
aperture
.
The
aperture
can
be
varied
up
to
20%
of the
span swept.
Group
delay measurements
can
be
made
on
linear
frequency
,
log
frequency
,
or
list
frequency
sweep
types (not
in
CW
or
power
sweep).
Group
delay
aperture
varies
depending
on
the
frequency
spacing and
point density
,
therefore
the
aperture
is
not
constant
in
log
and
list
frequency
sweep
modes
.
In
list
frequency
mode
,
extra
frequency
points
can
be
dened to
ensure
the
desired
aperture
.
T
o
obtain
a
readout
of
aperture
values
at
dierent
points
on
the
trace
,
turn
on a
marker.
Then
press
4
AV
G
5
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SMOOTHING
APERTURE
.
Smoothing
aperture
becomes
the
active
function,
and
as
the
aperture
is
varied
its
value
in
Hz is
displayed below
the active
entry area.
Application and Operation Concepts 6-37