NF WF1946B, Instruction Manual

Page: 105 / 204

4.2 Sweep
WF1946B
4-39
(4) Modulation type other than frequency
①
Modulation period: 50 ms and less
Step no. = sweep time (s)
×
5000
(rounded off, if modulation waveform is or , even number *2, also integer multiple of
4 if more than 3.2 ms. If other modulation waveform, even number if more than 1.6 ms *2)
② Modulation period: more than 50 ms, but 62.5 ms and less
Step no. = 250 (fixed)
(248 if the modulated waveform is
or )
③
Modulation period: more than 62.5 ms
Step no. = modulation period (s)
×
4000
(rounded off, if modulation waveform is step, even number)
(5) Exceptions
①
If the sweep type is changed after setting the sweep time, the step number remains the same.
For example, if the sweep type is changed from frequency to amplitude, the step number remains
as in item (1).
② If the modulation type is changed after the modulation frequency is set, the step number remains
the same. For example, if the modulation type is changed from frequency to amplitude, the step
number remains the same as in (3).
b. Secondary channel step number
Step no. = reference channel step no.
×
secondary channel sweep time (modulation period)
÷
reference channel sweep time (modulation period)
(If function is step, round up to even number *2, if other function, round off.)
*2: If rounded up/off results are odd, -1.
• Deriving step width
During linear sweep, step width = ――――――
During logarithmic sweep, step width = log
10
-1
[log
10
―――
÷
(Step number. -1)]
Step width during log sweep changes with step progression.
The step width during a log sweep changes according to the sweep progression.
Output of MARKER OUT is synchronized with sweep steps. Therefore, the range of difference in
value between marker value settings and the actual value of MARKER OUT is ± step width.
Span
Step number -1
Stop
Start