William Sommerwerck wrote:
Yeah, that's the sinc function/kernel but it does not mean that there's
any nonlinearity or response change over the published passband
of a properly ... sampled system.
There has to be some, because you can't have an infinitely narrow
sampling function.
of course not.
Please note the phrase "over the published passband." Or did I
miss your meaning?
I think we're both missing each other's meaning!
If I am confused... so you are saying with a narrower, more
perfectly-approximating-a-Dirac-Delta ... impulse response
( I am not 100% sure *that* is even correct ) that we would get a
wider bandwidth... which is probably assumption #1 of his whole
thing ( and a widely used assumption which he defends pretty well ).
The "bandwidth" has little to do with it. It's rather that, the narrower the
sampling function, the less "up and down" in the response. For practical
systems it amounts to no more than 1 or 2 dB at 20kHz.
Fair enough
--
Les Cargill