Справочник Пользователя для HP (Hewlett-Packard) 8360

Center frequency/span is another way of establishing swept

operation. This is just a different way of defining sweep limits. As an
example of center frequency/span operation:

Press 

 

Press 

 

 

The synthesizer is now sweeping from 3.5 to 4.5 

 (to view these

figures, press either 

 or 

 then 

 The data display

area indicates the center frequency, as well as, the span. Notice that
the green SWEEP LED is on.

While span is the active function, try the rotary knob and arrow
keys. This symmetrical increase or decrease of the frequency span
about the center frequency is one reason that center frequency/span
swept operation is used instead of start/stop frequency sweep.

Another example illustrates the subtleties of center frequency/span.

Press 

 

 

Press 

 

 

Notice that the center frequency changed. This is because the center

frequency could not accommodate a span of 8 

 without exceeding

the lower frequency limit of the synthesizer’s specified frequency
range. If the low or high frequency range limits are exceeded, the

inactive (center or span) function is reset. Experiment with the

rotary knob and the arrow keys as alternate methods of data entry.