Before manual control can be used,
manual
must be selected on the
SWEEP TYPE
screen,
see above; if
manual
has not been set, the message
mode is not manual
will be displayed
instead of the frequency.
In manual mode the frequency can be stepped through the sweep range, defined on the
SWEEP
RANGE
screen, using the rotary control or cursor keys. Every point of the frequency table is
stepped through if
step slow
is selected; if
step fast
is set then the frequency changes
in multiple step increments.
Step fast
cannot be set when the number of steps in the table is
small.
If
wrap
is set the sweep wraps-round from
start
frequency to
stop
frequency and vice-
versa; if
no wrap
is set the sweep finishes at either the
start
or
stop
frequency
depending on the direction of the rotary control or cursor keys.
Sweep Spacing
Pressing the
spacing…
soft-key on the
SWEEP SETUP
screen calls the
SWEEP SPACING
screen.
SWEEP SPACING:
♦
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
SWEEP MARKER FREQ
screen.
SWEEP MARKER FREQ:
progrm: 5·000 MHz
actual: 4·977 MHz
done
◊
A new marker frequency can be programmed directly from the keyboard or by using the rotary
control and cursor keys. Note that the marker frequency can only be one of the values in the
sweep frequency table; any value in the sweep range can be entered but the actual value will be
the nearest frequency in the table. When sweep is turned on, the actual marker frequency is
shown in the non-editable field below the programmed frequency. For the default sweep setting of
100kHz to 10MHz in 50ms (400 steps), the actual frequency of a 5MHz marker is 4·977 MHz.
The marker duration is for the number of 0·5ms intervals that the frequency remains at the marker
value; for fast and/or wide sweeps this will often be the 0·5ms minimum but for slow and/or
narrow spans the marker may last many 0·5ms intervals. To avoid anomalous conditions the
marker will not be exactly placed at the start and stop frequencies even though it can be
programmed to be so. The marker polarity and level is set up on the
cursor/marker…
menu
of the UTILITY screen, see System Operations section.
The marker frequency can be changed with sweep on but since the table of frequency values is
rebuilt with each change this can be a slow process, especially if the rotary control is used. It is
faster to switch sweep off, change the marker and switch sweep back on again.
Sweep Hold
The sweep can be held/restarted at any time at/from its current frequency by alternate presses of
the HOLD key or remote command.
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