21
MANUAL SWEEP off
◊
12.30% 2·5477 MHz
◊
wrap:on
◊
res: medium
done
◊
In manual mode the frequency can be stepped through the sweep range, defined on the
SWEEP
RANGE
screen, using the rotary control. Clockwise rotation sweeps the frequency up and
anticlockwise sweeps the frequency down; the
direction
setting on the
SWEEP TYPE
screen is ignored in Manual Sweep mode. As the frequency is swept the display shows both the
frequency at each step and the step position within the sweep, expressed as a percentage of the
total sweep range; 0% is the Start frequency and 100% is the Stop frequency. The resolution of
the frequency steps is set by the
res
olution soft-key. With
res:
coarse
the sweep range
is divided into 100 (1%) increments for the purposes of manual stepping;
medium
splits it into
1000 (0.1%) steps and
fine
splits it into 10,000 (0.01%) steps. Each complete turn of the
rotary knob corresponds to 36 steps; turning the rotary control rapidly will cause the frequency to
jump by more than one step. Sweep spacing (linear or logarithmic) is as set on the
SWEEP
SPACING
menu (see Sweep Spacing section below).
The frequency stepping resolution can be changed during a manual sweep such that
coarse
resolution can be used to quickly find a frequency of interest and
fine
resolution then
selected to step the frequency in smaller increments.
If
wrap
is set
on
the sweep wraps
−
round from
start
frequency to
stop
frequency and
vice
−
versa; if
wrap
is set
off
the sweep finishes at either the
start
or
stop
frequency
depending on the direction of the rotary control.
Exiting Manual Sweep mode (by pressing the
done
soft
−
key) returns the display to the
SWEEP
SETUP
screen with the instrument running at the last selected step frequency; the instrument is
still in Sweep mode but not sweeping.
Sweep Spacing
Pressing the
spacing
...
soft
−
key on the
SWEEP SETUP
screen calls the
SWEEP
SPACING
screen.
SWEEP SPACING off
◊
♦
logarithmic
◊
linear
done
◊
With
linear
selected the sweep changes the frequency at a linear rate; with
logarithmic
selected the sweep spends an equal time in each frequency decade.
Sweep Marker
Pressing the
marker
...
soft
−
key on the
SWEEP SETUP
screen calls the
MARKER FREQ
screen.
MARKER FREQ off
◊
program:10·0000 MHz
done
◊
When set to
sweep sync
AUX OUT will additionally output a marker pulse if the marker
frequency is set within the sweep frequency range. The marker pulse is approximately 25% of
the amplitude of the sweep sync pulse.
