I've been trying to find the correct keywords to ask my issue, but I keep getting nowhere. In fast block mode, where memory is not an issue, I'm measuring signals with a Picoscope 5242D. Taking readings at 125 MHz and subsequently downsampling (by averaging) to 25 MHz or taking readings at 25 MHz directly, which is functionally equal, is the subject of our ongoing debate.

Is there some sort of hardware filtering that occurs when selecting a lower sampling rate? If I were to measure at 25MHz, would the device just deliver every 5th sample (i.e., sample every 20ns) or would it do more?

The more you can tell me about this subject, the better. Thank you!

Warm regards,,
Werner M.

Are you writing your own application? if yes what language are you using? or are you using our PicoScope 7 software?

I will then be able to give you the answer you need.