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Re: Overtones and velocity factors



Original poster: dest <dest@xxxxxxxxxxxxx>

Hallo theorists (no any pun - i swear ^___^) : )

> Original poster: Paul Nicholson <paul@xxxxxxxxxxxxxxxxxxx>

> Gerry wrote (in another thread):

>  > about tfss270501 and md110701 spectral graphs.
>  > Is it  true that the spectral graphs are not harmonic in nature??

> True.  For example here are the resonant frequencies of an
> unloaded coil (one of Terry's, h/d=2.92)

and Marco Denicolai`s first coil (h:d = 4.58) for comparison
(on the right):

http://www.pupman.com/listarchives/1998/June/msg00181.html

                                   |
      Freq         Mode    Ratio   |    Freq         Mode    Ratio
a.  148.4kHz    1/4 wave   1.0     |   324 KHz        1/4     1.00
b.  353.4kHz    3/4 wave   2.38    |   813 KHz        3/4     2.51
c.  513.8kHz    5/4 wave   3.46    |   1475 KHz       5/4     4.55
d.  666.4kHz    7/4 wave   4.49    |   1766 KHz       7/4     5.45
e.  819.8kHz    9/4 wave   5.52    |   2053 KHz       9/4     6.34
f.  977.4kHz   11/4 wave   6.59    |
10. 1133.1kHz  13/4 wave   7.64    |
                                   |

note that data in rows "a-b" is similar, but starting from the row "c"
it looks like one sample is missing here, and all next data is
shifted back. i wonder what`s caused this - different h:d or it`s just
msms error?

> I'll just say a bit about propagation velocity with respect
> to wire length.

> Here are the figures for a coil h/d = 4.66, with 2078 metres
> of wire.

and Marco`s coil again on the right (h:d = 4.58) approx with
425 m of wire:

                                   |
    Freq        Mode         Owvf  |   Freq       Mode    Owvf
a.  61.9kHz     1/4 wave     1.72  |   324 KHz     1/4    1.84
b.  157.9kHz    3/4 wave     1.46  |   813 KHz     3/4    1.54
c.  229.7kHz    5/4 wave     1.27  |   1475 KHz    5/4    1.67
d.  294.4kHz    7/4 wave     1.17  |   1766 KHz    7/4    1.43
e.  355.6kHz    9/4 wave     1.09  |   2053 KHz    9/4    1.29
                                   |

again some inconsistency here, but this time in the coil itself - what
the @#$ row "c" is doing in there? : )
since this last coil has similar h:d ratio to Marco`s one, let`s
calculate and compare all the numbers from the beginning:

                                   |
    Freq        Mode        Ratio  |   Freq        Mode   Ratio
a.  61.9kHz     1/4 wave    1.00   |   324 KHz     1/4    1.00
b.  157.9kHz    3/4 wave    2.55   |   813 KHz     3/4    2.51
c.  229.7kHz    5/4 wave    3.71   |   1475 KHz    5/4    4.55
d.  294.4kHz    7/4 wave    4.76   |   1766 KHz    7/4    5.45
e.  355.6kHz    9/4 wave    5.75   |   2053 KHz    9/4    6.34
                                   |

what if one sample is really absent here - something like that:

                                   |
    Freq        Mode        Ratio  |   Fr eq       Mode   Ratio
a.  61.9kHz     1/4 wave    1.00   |   324 KHz     1/4    1.00
b.  157.9kHz    3/4 wave    2.55   |   813 KHz     3/4    2.51
c.  229.7kHz    5/4 wave    3.71   |    ?          5/4     ?
d.  294.4kHz    7/4 wave    4.76   |   1475 KHz    7/4    4.55
e.  355.6kHz    9/4 wave    5.75   |   1766 KHz    9/4    5.45
f.                                 |   2053 KHz   11/4    6.34
                                   |

like it? : ) then finally:

                                   |
    Freq       Mode   Ratio  Owvf  |  Freq       Mode   Ratio  Owvf
a.  61.9kHz    1/4    1.00   1.72  |  324 KHz    1/4    1.00   1.84
b.  157.9kHz   3/4    2.55   1.46  |  813 KHz    3/4    2.51   1.54
c.  229.7kHz   5/4    3.71   1.27  |  1166 KHz   5/4    3.60   1.32
d.  294.4kHz   7/4    4.76   1.17  |  1475 KHz   7/4    4.55   1.19
e.  355.6kHz   9/4    5.75   1.09  |  1766 KHz   9/4    5.45   1.11
f.                                 |  2053 KHz   11/4   6.34   1.06
                                   |

heck - you must be extremely careful when reading archives and must
constantly do the reality check on all info - that`s really suxxx coz
it takes a lot of time : E
so i want to ask people here a somewhat offtopic question (this may
help me to save some time):

very long time ago i have read a paper written by Marco Denicolai -
"Tesla Coil Tuning (zipped Word document, 158 kB) A theoretical
explanation of how optimal performance can be achieved (temptative)".
you can find it here:

http://www.elisanet.fi/dncmrc/tuning.zip

there is a "Figure 5: Energy transfered and transfer time vs.
coupling coefficient.", from which we can see, how much energy has
left in the primary, when k is not one of the "magic" values, that
permit full energy transfer. this plot is erroneous, if anybody have
correct version - plz send it to me.
thnx.