Can we control the sampling frequency in the 89400 Series analyzers?
The sampling frequency can effectively take on a wide range of values since we decimate the samples in our digital filters. To provide arbitrary frequency spans and RBW settings we also resample the data before we do the FFT. There are an almost infinite number of possible sampling frequencies possible, and the user does not control the sampling frequency directly, but rather gets a sampling frequency determined by the selected frequency span. For most cases this is a complicated relation. However there are certain spans for which the sample rate can be determined easily. If the span is a 'cardinal' value (this means exactly equal to 10 MHz/(2^N) where N is integer), the sample rate is 25.6 MHz/(2^N). If the pulse frequency you are looking at falls on or near one of these spans you could determine the sample rate exactly.