Secondary resonance freq

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: Secondary resonance freq

At 07:54 PM 6/10/98 -0500, you wrote:
>From:  Bill the arcstarter [SMTP:arcstarter-at-hotmail-dot-com]
>Sent:  Wednesday, June 10, 1998 10:16 AM
>To:  marco-at-vistacom.fi; tesla-at-pupman-dot-com
>Subject:  Re: Secondary resonance freq
>Marco, coilers,
>> I measured yesterday the resonance frequencies of my secondary. It is 
>> 4.3" diameter PVC tube, winded for a length of 19.7" with AWG 26 wire.
>> I got the following results:
>> 324 KHz
>> 813 KHz
>> 1475 KHz
>> 1766 KHz
>> 2053 KHz
>I measured some similarly 'weird' values for a friend's coil.
>Approx dimensions are 3 inch diam, ~24 inches long, way too many turns 
>of #30 or smaller magnet wire...
>First resonance was at 208 KHz
>Second was at 512 KHz
>Third was at 800 some odd KHz.
>I would have expected the 2nd resonance at 2x or 3x 208KHz but it didn't 
>work that way...
>I noticed that only the first resonance was very deep (an indication of 
>Q?).  The others did dip, but not as far, etc.
>Any ideas what this means?
>All resonance points shifted according to the proximity of stray 
>objects, etc.  Testing was performed w/o a topload and the output of the 
>sine generator was scoped directly through a sense resistor.
>-Bill Pollack (arcstarter)

I notice that the second peaks occur at ~2.5 times the fundamental in both
of your tests to within 2%.  That means something!  I don't know what but
there is a truth to be learned here.

        Terry Fritz