Re: Interesting Skin Depth Data

• To: tesla-at-pupman-dot-com
• Subject: Re: Interesting Skin Depth Data
• From: "Steve Cook" <Steve-at-g8cyerichmond.freeserve.co.uk> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
• Date: Sun, 12 Mar 2000 08:18:26 -0700
• Approved: twftesla-at-uswest-dot-net
• Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Any RF signal will contain harmonics of the fundamental frequency, the
actual content will depend upon the fundamental  frequency's waveform. A
square wave for example consists of an infinite number of harmonics.
Moreover a spikey waveform such as that from an arc will contain other
frequencies than the intended fundamental. Maybe somebody needs to do some
work on Fourier transforms to analyse exactly what happens. Personally
though I don't think the theory helps much. On a smaller scale, you get the
same problem every time you 'break' a switch contact. Try listening on an AM
broadcast receiver that is not tuned in to a station, and then turn the
lights off. The RSGB or ARRL handbooks might be worth looking at.

Steve
----- Original Message -----
From: Tesla List <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, March 11, 2000 5:53 PM
Subject: Re: Interesting Skin Depth Data


> Original Poster: "Ruud de Graaf" <rdegraaf-at-daxis.nl>
>
> >Original Poster: "Dale Hall" <Dale.Hall-at-trw-dot-com>
> >
> >Hi all,
> >The theory of using the resonator frequency may be perhaps
> >flawed when doing skin affect analysis.
> >
> >Based upon my oscilloscope observations the
> >frequency of an arc event is in the MHz range.
> >
> >The entire arc event is over in less that a microsecond (1MHz)
> >The arc risetimes I've measured are in the order of
> >~25nS to ~100nS (~20MHz-5MHz) and some even higher freq.
> >
> >The resonator serves to provide charge to the Csec.
> >
> >The discharge of Csec generates the arc freq quite independent
> >of the resonator ring up freq, for any one arc event.
> >
> >At 10-20 MHz arc oscillation, the ~30 MHy of the secondary
> >represents good XL isolation from the arc (like a series choke).
> >
> >At 10-20Mhz the skin affect may well be more of a factor in the human
case.
> >
> >Regards, Dale
> >
>
> Hi Dale,
>
> Well, is this good news!!! I hardly can wait to put my coil together and
do
> some measuring! What I don't understand is, how is it possible to hear
> cracking on the radio LW-band when coiling when there is no radiation on
> that frequency?
>
> Ruud
>
>
>

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