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1/4 Wave Theories - Trash Them!
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From: Barton B. Anderson [SMTP:mopar-at-uswest-dot-net]
Sent: Saturday, June 13, 1998 2:34 AM
To: Tesla List
Subject: Re: 1/4 Wave Theories - Trash Them!
Terry and Malcolm,
Thanks your comments on the phase relationship. I'm beginning to see the effects
of real world situation as compared to an ideal model. Ok, now I am starting to
wonder about the distance of wavelengths generated and if they reside at an
expected distance or something less. I'm not even sure where to speculate.
Thanks again for the comments,
Bart
Tesla List wrote:
> ----------
> From: terryf-at-verinet-dot-com [SMTP:terryf-at-verinet-dot-com]
> Sent: Wednesday, June 10, 1998 11:47 PM
> To: Tesla List
> Subject: Re: 1/4 Wave Theories - Trash Them!
>
> At 07:27 PM 6/10/98 -0500, you wrote:
> >
> >----------
> >From: Barton B. Anderson [SMTP:mopar-at-uswest-dot-net]
> >Sent: Tuesday, June 09, 1998 1:34 AM
> >To: Tesla List
> >Subject: Re: 1/4 Wave Theories - Trash Them!
> >
> >To Terry and all,
> >
> SNIP>>>>>>>>>>>>>>>>>>>>>
> >
> >Terry,
> >
> >When I said above "a net reactance", I was talking about the situation when
> XL=XC.
> >Because both are opposing and opposite, these reactances cancel. If XL =
> 24ohms,
> >then Xc = 24ohms (at resonance), but, if they are opposing and opposite (of
> which we
> >know this is true) isn't this net reactance "0"? and all that would remain
> is the dc
> >resistance of the coil?
> >
>
> Ok, there are a few details there, but you are basically correct.
>
> >I know I must be missing something here, I'm just not sure what and am
> hoping you or
> >someone can clear me up on this point. This is why I was thinking there
> should be no
> >phase variation (at resonance). I'm not in anyway trying to prove 1/4wave
> theory
> >(since I obviously don't know it that well), nor am I playing devils
> advocate, I'm
> >just trying to understand what I obviously don't. I think the above
> situation is
> >what is making me question the phase in this particular current measurement.
> >
>
> In an antenna, the phase variation is due to the time it takes the
> electromagnetic waves to travel the length of the antenna. In a 1/4 wave
> antenna, the length of the antenna is simply equal to the distance light
> travels in 1/4 of a cycle or d=c/(4Fo). There are ways, such as winding a
> coil with distributed inductance and capacitance, to make the distance much
> shorter. It is (was) commonly believed that in Tesla coils the
> electromagnetic waves only travel the length of the coil during 1/4 of a
> cycle instead of the much greater distance one would normally expect.
>
> >BTW, many many thanks for your replies. I've been contemplating yours and
> the rest
> >of the lists postings on this topic. There's so much unknown (not measured
> anyway)!
> >One thing that is certain to me, to validate tests, parallel tests of
> measurements
> >must be made including different methods of measurements. I hope everyone
> capable
> >will join in to help confirm, document, and speed up this process.
>
> I totally agree! I am now designing a special planar antenna to make
> voltage and current measurements using the antenna principle I happened upon
> a few days ago. This antenna will have much greater frequency response than
> the fiber-optics which is important for output arc measurements. This
> equipment is also much easier for others to reproduce than the fiber optics.
> My goal of phase measurements will also be more accurate at very high
> bandwidths. Output arcs appear to be creatures of the nanosecond range
> instead of the microsecond range. Fortunately, initial tests do indicate
> that that bandwidth will be high enough (hundreds of megahertz). The fiber
> optics have been indicating that high frequency information is being lost to
> a degree. I hope it works :-)) There are others doing the same type of
> work as I which will provide the very important function of testing the
> principles in a totally different environment. I seem to be a bit ahead of
> them at the moment! :-)
>
> >
> >My very best,
> >Bart
> >
>
> Best regards,
>
> Terry Fritz