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RE: Interesting Skin Depth Data



Hi Steve, and All,

Your statement:
>A square wave for example consists of an infinite number of harmonics<

 is a bit vague as to which harmonics, amplitudes, and phase produce what, so 

for those who wish more accurate detail:

An ideal Square Wave:
 consists of the fundamental frequency and an infinite number of odd harmonics
 the amplitude of each harmonic diminishing in 
 proportion to the reciprocal of its harmonic order,
 with respect to the amplitude of the fundamental.

An ideal Sawtooth Wave:
  consists of the fundamental frequency and an infinite number of odd and
even harmonics
  The odd harmonics are in phase and 
  the even harmonics are 180 degrees out of phase at time zero.

Many possibilities exist with Single Peaked Waves exhibited by a TC Sec HV
pulse:
 some possibilities:
 Fundamental plus 2nd harmonic lagging by 90 degrees at time zero
   adding 4th harmonic either in phase with 
     or leading the fundamental by 90 degrees
     or 180 degrees out of phase with the fundamental at time aero.

If someone wishes harmonic, amplitude and phase content
 of other waveshapes, just ask.

A viewed waveshape can be analyzed as to this content.
The Philco text below contains numerous example drawn waveshapes, 
explaining their composition.

There are numerous good college engineering texts, 
but they tend to be quite mathematical.

However a very practical reference is: 

Philco Field Engineers Data Handbook

TechRep Division, Fort Washington, Pennsylvania
written for the Armed Forces and Industry, copyright, 1957. (I was 12)

I don't know if there is a present source. 
Let the list know, if someone finds a source.
My copy is a bit battered, but no less valued.

Regards, Dale

-----Original Message-----
From: Tesla List [mailto:tesla-at-pupman-dot-com]
Sent: Sunday, March 12, 2000 7:18 AM
To: tesla-at-pupman-dot-com
Subject: Re: Interesting Skin Depth Data

Original Poster: "Steve Cook" <Steve-at-g8cyerichmond.freeserve.co.uk> 

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
>
>
>