🚀 go-pugleaf

Steve Sousa wrote:
> "David L. Jones" <altzone@gmail.com> wrote in message
> news:h8B0m.53620$FI5.3564@newsfe12.iad...
>> 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!
>>
>
> Hello:
>
> Since you're into it, why don't you compare the refresh rate of
> digital vs analog scopes?
> Also known as the waveforms-per-second capability? It's something i'm
> very curious about in practice, and also, do the digitals behave as
> the analogs (like a low-pass filter) when you increase the freq of a
> wave-form or suddenly start aliasing?
>
> Thank you.
> I really enjoy your blog
>
> Best Regards
> Steve Sousa

It's not only about waveforms-per-second, it's also about the capture and 
display engine as well.
The manufactuers have various technologies (e.g. Tek Digital Phosphor) to 
make their digital scopes have an "analog type" display and response, and 
they work superbly. In fact they can be better than analog in many respects. 
But that performance costs money, so you have to start paying around say the 
$5K mark before you get a digital scope that really performs like an analog 
one in terms of variable display intensity, response time, and capture 
dead-time.
See here for more info:
http://www.tek.com/products/oscilloscopes/dpo_technology/
http://www.tek.com/Measurement/App_Notes/Technical_Briefs/55-13757/eng/55w-13757-0.pdf

Lower end scopes don't have these "analog like" display technologies, so 
then "waveforms-per-second" is pretty much the basic benchmark. Modern 
scopes are pretty darn good though, and even the low end cheap ones are 
streets ahead of previous generation DSO's.
Those who haven't used a modern high end digital scope don't know how superb 
they can really be.

With modern fast real-time deep memory scopes, aliasing is pretty much a 
thing of the past.

Might make an interesting future blog...

Dave.

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