Zoom If Span Change (Frequency)

Zoom If Span Change determines whether Time Data is switched to Zoom mode (complex samples) when the Span is changed in Baseband mode (real samples). Note that in Baseband mode, the Start frequency is always 0 Hz.

When Zoom If Span Change is selected, changing the Span will adjust the Start and Stop frequencies to center the desired Span around the current Center frequency. This causes the Start frequency to change from 0 Hz, causing Time Data to switch to Zoom mode.

However, when Zoom If Span Change is cleared and the Span is changed, the Start frequency will remain at 0 Hz and only the Stop frequency will be adjusted to reach the desired Span. This also means that the Center frequency will change when you adjust the Span.

The following picture illustrates the effect of this parameter when changing the span.