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Why is more bandwidth worth considering?

The effective bandwidth of a digital oscilloscope is dependent on its sample rate which also depends on memory length. This is discussed in a separate article. However, how much analogue bandwidth is required?

The benefits of longer memory in oscilloscopes

Larger memories offer two advantages. Firstly more memory allows a longer acquisition time. Secondly, for the same acquisition time, using a larger memory can result in a higher sample rate – which actually means that the effective bandwidth of the measurement is increased.