There are now so many DS1000Z threads that it's difficult to know where to post, but since we've been discussing the subject of sample rates and aliasing here, I figured I'd post it here (with a link over from the main DS1074Z thread).
Until now, the only info about the 20MHz BW limit roll-off I've seen was
this graph made by seronday (which I used earlier in this thread when making a possible overall BW graph for the DS1000Z).
Well, I don't have the necessary equipment to do a proper BW graph (no signal generator that goes high enough), but my simple test seems to indicate that either seronday's graph is wrong - or there is a lot of difference among the various models (I've got a MSO1074Z). Perhaps some other owners would like to test this as well?In seronday's graph, he shows 100MHz as being attenuated to about -11.3dB when the 20MHz BW limit is turned on. Edit: I think I stayed up too late working that night
- seronday's graph pretty well matches my own measurement.
My test shows a 100MHz 400mV sine being attenuated to ~-7.8dB.
First, here is a 100MHz sine on the DS2000, with and without the 20MHz limit on (-13.2dB down):
And here is a 100MHz sine on the MSO1000Z, with and without the 20MHz limit on (-7.8dB down):