Re: Resonant Systems

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

However, this is a good technique if you digitize a bunch of samples and
then use the samples to measure the power spectrum.  I've used it to
characterize filters, particularly where the "equivalent noise bandwidth"
was of interest, as in a radiometer.  If you want to crunch a lot of numbers
and run some test signals through your digitizer, you can get away with a
pretty bad digitizer (in terms of nonlinearities, sampling jitter, etc.)...


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, February 23, 2002 5:24 PM
Subject: Re: Resonant Systems


> Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<evp-at-pacbell-dot-net>
>
> Tesla list wrote:
> >
> > Original poster: "Paul Nicholson by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <paul-at-abelian.demon.co.uk>
> >
> > Ed Phillips wrote:
> >
> > > feed a band-limited noise-like voltage into a scope and set the
> > > trigger level near zero, the waveform near the trigger point will
> > > be pretty much like a sinusoid, become more noisy as you look out
> > > toward a time of 1/BW.
> >
> > Good idea which demonstrates the point well.  Does this give us a
> > neat way to measure secondary Q, given a suitable noise source
> > (binary sequence gen, perhaps)?
> > --
> > Paul Nicholson
> > --
>
> No, don't think so.  The time resolution of the trace is far too poor
> for that, as is the accuracy of triggering.  The simple signal generator
> and scope method is easy and will work far better.
>
> Ed
>
>
>