oscilloscope question

I've never seen one that can do that specifically. Perhaps one or two really really high end ones designed for detailed signal analysis?... You'd usually have to suck the raw data out and post-analyse it on a PC, or use a different tool like a Dynamic Signal Analyser perhaps. There are some smart scopes like the CleverScope for example that can do arbitrary math using a user-entered formula on the captured data.

Dave.

I did that sort of thing 30+ years ago with Tektronix Signal Processing System (essentially a digital 7704A or Transient Digitizer and PDP-11). Digitize => FFT => Multiply => RFFT

I'd be surprised if it wasn't a pretty standard thing to do today.

Me too. Our scope has the standard FFT but I have to do the post processing PC thing.

All our Tek digitals, including my low-end TDS2010, do p-p, but not within a specified bandwidth; add a filter for that. Also RMS, frequency, rise time, fall time. period, and pulse width.

But roger the 547 with a 1A7 or a W. You can connect a digital scope to the vertical sig out of a 547 to snapshot the results.

There's also the AM502 diffamp, kinda like a 1A7, that's a great front-end for a digital scope.

I have a dozen or so 547's.

John

I just remembered that my new Rigol DS1052E has a user definable input bandpass filter option (among others), and it automatically measures p-p and a dozen other things, so looks like it is possible to do this on the cheapest bench scope on the market!

Dave.

On Wed, 19 Aug 2009 18:57:10 -0700, David L. Jones wrote (in article ):

How do you like your Rigol? Any buyer's remorse? Any regrets (even if it was "I shoudda got the 200 MHz model...")?

Dave (too)

Very nice. And for the price, can't be beat. No regrets. See my Blog #22 for a Rigol expose', link below. Looks like the 100MHz model has dropped in price since I got my 50MHz one though.

Dave.

I don't think peak to peak in a bandwidth makes sense. Perhaps you are thinking of RMS energy in a bandwidth. Modern (hell, even old) signal analyzers can do this. The old HP3562 had this feature. You could also just use a filter box (Kronhite), or rolll your own, then feed it to a true RMS meter.

I suppose if you really needed peak to peak, you could do the filtering, then either watch on a storage scope or attempt to find the peak to peak with instrumentation, but I really think RMS is more indicative of performance. You know how noise measurement go. The longer you study peak to peak, the larger value you will get due to the randomness of noise.

it won't give you a scalar, but a FFT may be able to get you what you need (rolling stones flashback)

a écrit dans le message de news: snipped-for-privacy@e34g2000vbm.googlegroups.com...

I guess you can do it for example with a Lecroy, even a quite old one :

- ch1 = acquisition

- Math1 = FFT of channel 1

- Memory1 = a rectangular window (may be you can generate it in time domain with a pulse generator and just store it once ?)

- Math2 = Math1 x Memory1

- Math3 = iFFT of math2 and peak-to-peak measurement of Math3

There are also signal processing toolboxes on several high end scopes, as well as built in Mathlab...

Friendly, Robert

Why do you "have to"? If it's got FFT just spool that result over to the PC. It doesn't make much of a difference whether the scope or the PC does the job, except that the scope is usually faster.