"A non-sampling oscilloscope with limited bandwidth could just as easily miss a narrow pulse because of bandwidth constraints no matter how high its sampling rate."
That is the point of the thread. Even a wide bandwidth analog scope used to show a 500nS pulse at a 200Hz repetition rate will have a hard time, while any DSO worth the name will have no problem with it. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -----Original Message----- From: David <davidwh...@gmail.com> Sender: time-nuts-boun...@febo.com Date: Wed, 18 Apr 2012 18:11:29 To: Discussion of precise time and frequency measurement<time-nuts@febo.com> Reply-To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Subject: Re: [time-nuts] Rigol scopes On Wed, 18 Apr 2012 13:56:18 +0000, shali...@gmail.com wrote: >That's why the default mode for a DSO should always be "pulse detect" or >whatever the manufacturer calls it, unless you know what you are doing. As far >as I know, all DSOs have this or an equivalent mode where the ADC runs at full >speed regardless of sweep speed, and the min and max readings between two >display points are stored. If you are in a condition that would otherwise >result in aliasing, the trace will look like a big fat trace, just like on an >analog scope if you are probing a 10MHz signal at 1mS/div. Do the low end Rigol oscilloscopes actually support peak detection? The manual only describes an envelope mode without any ability to set the number of envelopes like a Tektronix 2440 can for single shot peak detection. When I was in the market for a DSO a couple years ago, the Rigol representatives could not answer. I ended up rebuilding an old Tektronix 2230. >You get the same issue with an analog sampling scope, except that those don't >have a "pulse detect" mode, so they WILL lie to you unless you know what you >are doing. It is not a "digital storage" issue, it is a sampling issue. Sampling oscilloscopes are in a class all to their own and very specialized. Their low sample rates hinder capturing infrequent events but if a repetitive glitch is there, they can still see it. A non-sampling oscilloscope with limited bandwidth could just as easily miss a narrow pulse because of bandwidth constraints no matter how high its sampling rate. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.