From: Mike Monett
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Subject: Re: Binary Sampler
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Date: Tue, 21 Jan 2003 14:19:55 -0500
NNTP-Posting-Date: Tue, 21 Jan 2003 14:19:19 EST
Organization: Bell Sympatico
John Larkin wrote:
> On Tue, 21 Jan 2003 11:08:20 -0500, Mike Monett
> >The amazing thing is how it acquires the signal after slewing through a
> >large range. The acquisition takes one sample, just as the simulations
> >show. There is no overshoot, ringing, or long dribble time as it settles
> >on the new amplitude. The capture is instantaneous.
> What's amazing is how slow it is. It's like crawling across the
> desert, and being surprised at how fast you can stop.
Yes, but it's amazing how accurately you know where you are in the
Besides, since it scales with frequency, you can increase the offset
frequency and keep the same tracking value. This speeds waveform capture.
You can also adjust the tracking value for any desired tradeoff in
acquisition time vs tracking error. Do it fast to get an idea where the
interesting areas are, then slow it down to examine in detail.
If you adjust the tracking value for the same effective resolution as
conventional sampling, ie 3% to 5% of the amplitude, then it is much
faster than conventional sampling.
Conventional sampling degrades with frequency. HP dropped the ringing and
overshoot spec completely on their highest frequency sampling scope.
So pretty pictures are nice, but when you really need to know the value
at a point in the waveform, it's hard to beat.