Re: Variation of secondary Q

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

Original poster: "Paul Nicholson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <paul-at-abelian.demon.co.uk>

Terry,

Here's some alternative plans:  Got a soundcard?  

Plan (a)
Take the ringing signal at Fres and pick it up on a scanner in
upper sideband mode.  Feed the scanner audio into your soundcard
to get a digitised ringdown waveform.

Plan (b)
Take the ringing signal, amplify it, and mix it with a square wave
oscillator of around 75 kHz.  Pass the mixture through a diode, a
low pass RC filter, then feed the residue into your soundcard.

Plan b has the advantage of greater bandwidth - what's the max
conversion rate of your soundcard?  If it'll do 44k samples/sec
then you can feed in some 60kHz from a ferrite rod to get a 15kHz
calibration marker mixed with the 5kHz ringdown.
--
Paul Nicholson
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