🚀 go-pugleaf

On 20 July, 12:54, "David L. Jones" <altz...@gmail.com> wrote:
> blackhead wrote:
> > On 20 July, 10:06, Ray <s...@spamalot.com> wrote:
> >> blackhead <larryhar...@softhome.net> wrote
> >> innews:0268880f-5658-44fe-8908-579f2f1031ba@s31g2000yqs.googlegroups.com:
>
> >>> On 19 July, 23:02, "David L. Jones" <altz...@gmail.com> wrote:
> >>>> John Larkin wrote:
>
> >>>>> Do the scopes work?
>
> >>>> Yep, they work. So Rigol are obviously getting away with it by hook
> >>>> or by crook.
> >>>> If AD are deliberately under-speccing their normal chips, then
> >>>> it's a clever ploy by Rigol to exploit it.
>
> >>>> Dave.
> >>>> --
> >>>> ---------------------------------------------
> >>>> Check out my Electronics Engineering Video Blog &
> >>>> Podcast:http://www.alternatezone.com/eevblog/
>
> >>> So give it a 1 Ghz signal and see if it it looks right then.
>
> >> Umm, no. Ever heard of Nyquist?
>
> >> Plus to see anything like a signal for your eye's benefit, you're
> >> better
> >> off with x10 sampling.
>
> >> So 100MHz is more on the mark. Does it allow you to simply plot the
> >> points
> >> without the "join the dots"?
>
> >> BTW if you had exactly 1GHz going in, and it manged to sneak pass
> >> the front
> >> end, you'd end up with a straight line at some DC level.
>
> >> Ray- Hide quoted text -
>
> >> - Show quoted text -
>
> > I have heard of Nyquist, just forgot to apply him in this case :)
>
> and you forgot about the analog bandwidth too, that's kinda important!
>
> > There will be an anti aliasing filter in the front end so you wont see
> > much if you put in anything close to half the sampling rate = 500Mhz.
>
> Err, the front end bandwidth is only 50MHz!
> Kinda hard for any signals higher than that to sneak past, as Ray said.

Yes, but that's the 3dB bandwidth, isn't it? i.e the frequency at
which the voltage is 1/sqrt2 that of its value at DC. Hence you should
still be able to see signals higher than 50Mhz. Plonk a signal
generator on it and tell us what you you see ;)


> Dave.
>
> --
> ---------------------------------------------
> Check out my Electronics Engineering Video Blog & Podcast:http://www.alternatezone.com/eevblog/- Hide quoted text -
>
> - Show quoted text -