Nope...you got it just right!
As Simon pointed out, its all about knowing what information you want to get from the "re-constructed" wave. If you want all the detail, you have to sample at least 2f of the highest harmonic content. Square waves with fast rising leading edges are a real mutha!! Its why we sold alot of multi-gig one-shot samplers! For repetitive waveforms, averaging with a sample rate much slower and randomly distributed across the signal results in good reconstruction but is not "realtime" or one-shot capable.
Curt
Nigel Gunn G8IFF/W8IFF wrote:
According to Mr Nyquist (I think that's who it was) you only need to sample at twice the highest frequency contained in the sampled waveform but remember that here we are talking about twice the frequency of the highest harmonic contained in the waveform so 8KHz wouldn't be sufficient for a 4KHz square wave but would be sufficient to reconstruct a 4KHz sine wave..... or is my theory screwed up as well?
Gordon JC Pearce MM3YEQ wrote:
Hmm. That's not quite true.
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb