🚀 go-pugleaf

On Jun 28, 6:03 pm, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> On Sun, 28 Jun 2009 12:45:41 -0700 (PDT), Richard Henry
>
>
>
> <pomer...@hotmail.com> wrote:
> >On Jun 24, 7:18 pm, "David L. Jones" <altz...@gmail.com> wrote:
> >> Check out a rather unusual phenomenon you can see on your oscilloscope in my
> >> latest blog (#14):http://www.alternatezone.com/eevblog/
> >> See if you can get it to happen on your scope!
> >> I'll offer a free subscription to my blog for the best screen shot posted
> >> :->
>
> >> Oh, and the probe doesn't have to be shorted either.
>
> >> Have fun.
> >> Dave.
> >> --
> >> ================================================
> >> Check out my Electronics Engineering Video Blog & Podcast:http://www.alternatezone.com/eevblog/
>
> >His schematic of the scope probe and scope input are oversimplified to
> >the point of incorrectness.  Also, he ignored the low-pass nature of
> >the oscilloscope input, which might contribute to the clean
> >"sinusoidal" waveform.
>
> Scope vertical amps don't ring.

That was not my point.  The limited low-pass band of the input
amplifier and sampling circuit will either completely filter out
higher-frequency components, or will alias them down.  If you are
seeing a nice sinusoidal waveform on an oscillioscope whose
fundamental frequency is close to the frequency limit of the scope,
chck it with a higher-frequency device.