From: Mike Monett
X-Mailer: Mozilla 2.02 (Win16; I)
Subject: Re: Binary Sampler
References: <3E26E3E2.firstname.lastname@example.org> <3E2922B4.C3B@sneakemail.com> <3E2A07F4.email@example.com> <3E2A5081.4C97@sneakemail.com>
Date: Mon, 20 Jan 2003 17:49:36 -0500
NNTP-Posting-Date: Mon, 20 Jan 2003 17:49:03 EST
Organization: Bell Sympatico
> "John Larkin" wrote in
> message news:firstname.lastname@example.org..
> > On Sun, 19 Jan 2003 22:04:26 GMT, "Mike" wrote:
> > >The only way I'd know of to generate the sample
> > >clock for Mike's scheme is to either generate it from the same source as
> > >that used to generate the input, or to derive the clock from the input,
> > >use it to sample the input.
> > It think this has been done. It's called 'triggered sweep.'
> I was thinking of locking a PLL to the input and using the edges of the
> recovered clock as the triggers, rather than triggering on each edge of the
> input signal. You get some noise rejection with the PLL, but with the amount
> of noise Mike's adding, I suspect the PLL wouldn't lock... Of course,
> neither would driving a trigger directly from the noisy input signal. Were
> you thinking of something different?
> -- Mike --
Mike, I'm sorry I haven't seen this before, and you post has dropped off
the server so I have to guess at the content.
If you use the heterodyne technique described on my web site, you don't
even need a trigger. All you need to know is the frequency of the signal
you are trying to recover.
After the samples are in memory, it is easy to reconstruct the waveform
and display it with whatever starting point that is desired.
As John mentioned, Lecroy has a patent on a sampler that uses a very high
frequency clock. The same technique could be used with their instrument.