Re: transmission line theory and secondary resonance

• To: tesla-at-pupman-dot-com
• Subject: Re: transmission line theory and secondary resonance
• From: "Gavin Dingley" <gavin.dingley-at-astra.ukf-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
• Date: Sat, 27 May 2000 17:09:19 -0600
• Approved: twftesla-at-uswest-dot-net
• Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Hi Bob,

Tesla List wrote:

> Original Poster: "Robert Jones" <alwynj48-at-earthlink-dot-net>
>
> Hi Gavin,
>
> Yes you have it right.   But note that med C and a lump equation does
> produces reasonable answers for f  (10% error for the average H/D ratio
> coil) for the reasons I have already posted. A fortuitous bit of luck for
> Teslaphiles. It want however produce the correct voltage (this may be a very
> controversial view)
>

But is this only when a top load is included, otherwise Cmed will give
incorrect
answers when a coil is resonating on it's own; that in incorrect by a
substantial amount:-

fr = 1 / (4 sqr (L * (Cmed + Ctop))) works well (within 10%)

but

fr = 1 / (4 sqr(L*Cmed)) is highly inaccurate

Is this correct? Or both work practically with normal H/D ratios
(i.e. Diameter = 4.5 * Height)?


>
> Note also that  the TM equation should be using the mutual inductance per
> unit length but again more luck. In the average coil this is equal to the
> inductance divided by the length of coil.  The full equation with all
> effects will be posted at some point.
>
> I and others have  failed to find a formula for the intrinsic C of an
> isolated hollow cylinder but I have not given up hope.  If you find one I
> would appreciate you posting it immediately.
>
> There is a special version of Wintesla that calculates intrinsic C and gave
> an answer within a few % of one measured coil.  The regular one calculates a
> voltage weighted C that may be similar to med C.  I direct you to Terry
> Fritz for either the special one or an explanation for the voltage weighted
> one.
>
> What does isotropic mean with in the context of your reply?

I'll have to send you an article I have off list, it's too much to try and
explain. However, the same article may help in calculating Cintrinsic.
Basically
I mean the type of capacity associated with a top load, as opposed to one being
formed from two parallel plates.


>
> Regards Bob
>

Thanks again, Bob, I find this stuff interesting and useful, even if it
stretches a little beyond my scope of understanding.

Cheers,

Gavin

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