HP 8360 - Manual (Page 38)

Center
Frequency/Span
Operation 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.
1-6 Getting Started Basic