Re: More Coupling...

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

Original poster: "Marco Denicolai by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Marco.Denicolai-at-tellabs.fi>






"Tesla list" <tesla-at-pupman-dot-com> on 23.12.2000 21:14:34

To:   tesla-at-pupman-dot-com
cc:    (bcc: Marco Denicolai/MARTIS)
Subject:  Re: More Coupling...



>Original poster: "Barton B. Anderson by way of Terry Fritz
<twftesla-at-uswest-dot-net>" ><tesla123-at-pacbell-dot-net>

Hi Bart

>This is kind of interesting to me. We have heard at times that BIG COILS can
>get away with running at higher coupling values than smaller coils. If I
was to
>take a look at your K values you measured, I would think "ok, not really
>different than what I've seen lately", but if you tap at about 8 turns
(approx.
>tune point for 0.1uF, maybe a little less), the value of K increases by about
>0.027. So for a base line of zero, you measured 0.169, but add 0.027 to it and
>baseline is at a K of 0.196! Marco, your running at higher K values than you
>measured for the height assuming main components have not changed. You
probably
>already know this, but thought I'd throw that out for everyones benefit.

Well, I DIDN'T know about that: thanks for pointing it out.

>acmi values for Ls=80.3mH, Lp=104uH
>Marco's measured values are Ls=80.221mH, Lp=103.8uH

Almost all ok, besides that I also measured leads inductance as 4.7uH,
therefore:

Lp = 103.8 - 4.7 = 99.1 uH (see  http://www.saunalahti.fi/dncmrc/th_ccoef.htm)

And as I mailed to you privately, actual number of used turn was 9.5 (not 9).

Hopefully you'll be able (again) to get values from acmi like those I measured
:)

Regards
















Tesla list wrote:
>
> Original poster: "Marco Denicolai by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <Marco.Denicolai-at-tellabs.fi>
>
> Hi Bart.
>
> I have measured some time ago Thor's coupling coeff. and reported my
> results at:
>
>
> <http://www.saunalahti.fi/dncmrc/th_ccoef.htm>http://www.saunalahti.fi/dnc
> mrc/th_ccoef.htm
>
> I can't recall if Paul has already used my data or not.
> The measure was taken by first measuring Lprimary and Lsecondary, then
> Lprimary+secondary (in series) at different primary height.
> >From that M was derived and then k.
>
> I got a pretty linear curve: the little curvature near k=0.12 is probably
> due to
>  the fact that I was forced to change a connection lead for
> that measurement point.
>
> Regards
>
> "Tesla list" <tesla-at-pupman-dot-com> on 22.12.2000 04:28:02
>
> To:   tesla-at-pupman-dot-com
> cc:    (bcc: Marco Denicolai/MARTIS)
> Subject:  Re: More Coupling...
>
> Original poster: "Barton B. Anderson by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <tesla123-at-pacbell-dot-net>
>
> Hi Paul and Everyone,
>
> My reply here is to ask (plead) for more coiers to make coupling
> measurements.
> All that is needed is a DMM capable of volt and amp readings (or meters
> capable
> of this). Also needed is a primary that can be moved above and below the
> secondary base line in steps (or the secondary to achieve the same result).
> Measurement is easy (we can define that later).
>
> If case you haven't kept up with this thread, I have found an increase in
> coupling error to Paul's program "acmi" predictions (error increases in the
> direction of increased coupling). What I would like to find out with your
> help
> is:
>
> 1. is current changing during measurement (and not realized),
> 2. is the flat primary shape causing the error,
> 3. if #2 is correct, does acmi need to apply a correction of some type,
> 4. if #3, is this true for only flat primary's?
> 5. Lot's of other little tid bits to increase our coupling knowledge.
>
> So we need some flat, helical, and conical coupling measurements as well.
> This
> type of comparison has been needed for some time and the information will add
>
> another little wrinkle in our coiling brains.
>
> Any takers? Anyone?
>
> Thanks,
> Bart