Re: 1/4 wave theory/cite the variance?

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi,

I should point out that much of the 1/4 wave "myth" comes from the Colorado
Springs Notes as do a fair number of other "myths" about Tesla coils.

The Colorado springs notes are Tesla's personal notes he took at the time.
He NEVER intended for someone to find it 80 years later and publish it and
send tens of thousands copies all over the world to hungry Tesla coil
builders.  If he had, he would have removed all the mistakes.

Tesla used the 1/4 wave thing a lot in his calculations "there" because
that is all he had "at that time".  Much of the notes are filled with Tesla
struggling with the fact that "it didn't work".  Later on, Tesla certainly
understood the problems with his old calcualtions back then.  However, If
you read the notes, they do sound like Tesla had it all figured out,
"before he tested it"!

So be very careful of getting "facts" from the Colorado Springs notes.  The
experiments are wonderful but the "analysis" was not ready for prime time.
I hate to hear people argue that soemthing there is the truth when Tesla
himself would not defended it in light of his later understanding.

For fun, if one has any old Tesla notes form 20 years ago.  Imagine how
they would sound "now" if they suddenly made the six o'clock news!  Maybe I
should go burn mine :o))

Cheers,

	Terry


At 06:27 PM 2/16/2002 +0000, you wrote:
>Hi Harvey,
>
>> pray tell me what this deviance from
>> quarterwavelength actually consists of? Is it 10%
>> lower? Is it 15% by added top polar capacity? Is it no
>> known figure of percentage basis compared to that
>> quarterwavelength value, 
>
>The 1/4 wave resonant frequency of a wire, when wound into a
>solenoid, is typically more than 50% higher than that of the
>straight line value.
>
>The extraordinary persistance of the wire-length myth comes
>from the willingness of people to accept things on faith without
>making even the most basic of cross checks.
>
>Take a typical TC secondary and measure its unloaded Fres.
>Compute the free space 1/4 wave length and compare it to the
>wire length.
>
>For example, Terrys 30" coil, in metric units:
>
> Diameter: 0.261 metres
>    Turns: 1000
>
>therefore wire length = 0.261 * PI * 1000 = 820 metres.  Now this
>is a quarter-wave in free space at 300x10^6/(820 * 4) = 91.5 kHz.
>
>When you measure this coil, the actual Fres is 148 kHz.  If you'd
>tuned your primary to match an expected 91.5khz, it simply wouldn't
>work.  This sort of difference is typical, and the difference gets
>greater as the H:D ratio is reduced.  
>
>There, that was a simple check that could have been done by anyone
>in the last 10 decades.  You can't afford to rely on faith in this
>business.  Criticism, checks, cross-checks, and more checks. 
>Absolutely essential.  Makes it darn hard to make reliable progress
>if you're working alone.  Thank goodness for this list.  This is the
>first time in the history of Tesla coiling, as far as I know, that
>so many people (800+ now I believe) have come together in a rational
>forum to compare notes and ideas.  We are very privileged to live in
>this era of Pentiums and pupmans.  Lets try to do justice to that
>position.
>
>See the comments and graph in 
> http://www.abelian.demon.co.uk/tssp/misc.html
>
>> I submit that this is mere jumping on a bandwagon of derision 
>
>No, science doesn't work like that. The bottom line is: Nature Rules.
>--
>Paul Nicholson
>--
>