User Manual

Chapter 2 Front Panel Operation RIGOL
User’s Guide for DSA800 Series
2-9
CF -> Step
Set the current center frequency as the CF step. At this point,
the CF step will switch to "Manual" mode automatically. This function is usually
used with channel switching. Take harmonic waveform measurement for example:
locate a signal at the center frequency of a channel, execute CF-> Step and then
press the down direction key continuously to measure each order of harmonic in
sequence.
SPAN
Set the span of the analyzer. The change of this parameter will affect the frequency
parameters and restart the sweep.
Span
Set the frequency range of the current channel. Press this key to switch to center
frequency/span input mode. The center frequency and span are displayed at the
lower left and right sides of the grid respectively.
Key Points:
 The start and stop frequencies vary with the span when the center frequency
is constant.
 In manual span mode, the span can be set down to 100 Hz (the only way into
the zero-span mode is pressing the Zero Span menu option) and up to the
full span described in “
Specifications”. When the span is set to the
maximum, the analyzer enters full span mode.
 Modifying the span in non-zero span mode may cause an automatic change in
both CF step and RBW if they are in Auto mode. Besides, the change of RBW
may influence VBW (in Auto VBW mode).
 Variation in the span, RBW or VBW would cause a change in the sweep time.
 In non-zero span mode, neither “Video” trigger nor “1/Δtime” readout
function is valid.
 You can modify this parameter using the numeric keys, knob or direction keys.