HP 8642A Operating Manual page 80

Model 8642A/B
Operation
RF Frequency Sweep (cont'd)
How to Set Sweep Time for Stepped Frequency Sweep
(Using Sweep Time to Set Frequency Step Size and Number of Steps)
The operating characteristics for sweep time are as follows:
Minimum Sweep Time
Maximum Sweep Time
Sweep Time Resolution
Minimum Frequency Sweep Step Size
275 ms
999s
1 ms
1 Hz
Minimum Frequency Dwell Time Per Point:
Settling Status
Special Function 119
(Disable Settling)
Special Function 219
(Re-enable Settling)
8642A
60 ms
110 ms
8642B
80 ms
135 ms
Stepped Frequency Sweep Calculations
Since the sweep step size is not directly selectable, the following calculations provide
ways to determine:
1) the number of steps automatically selected (page 3-53)
2) the frequency step size automatically selected (page 3-54)
3) the required sweep time that will select a desired number of frequency steps (page
3-54), and
4) the required sweep time that will select a desired step size (page 3-57).
However, these calculations do not directly apply to situations when the start end-point
is equal to the stop end-point (zero span). Refer to "Zero Span for Stepped Frequency
Sweep" on page 3-64 for information about X-axis steps in zero span.
The minimum frequency dwell time per point is different depending on whether you
have an 8642A or 8642B and whether you have selected Special Function 119. So,
whenever you see the term "Min. Dwell Time" in a calculation, use the table above that
lists the Minimum Frequency Dwell Time Per Point to determine the value of that term.
Also, frequency points are truncated to 1 Hz. Span is always an integer since end-points
are integers.
1) Calculate the number of steps automatically selected.
The number of steps is the minimum of:
1023
or
| Start Frequency (in Hz) — Stop Frequency (in Hz) |
or
INTEGER OF | *™» ^ m e (m ms)
)
^
Mm. Dwell l i m e (in ms)
3-53