Quarter Wave Calculations, HELP!!!

From:  Malcolm Watts [SMTP:MALCOLM-at-directorate.wnp.ac.nz]
Sent:  Thursday, April 16, 1998 2:38 PM
To:  Tesla List
Subject:  Re: Quarter Wave Calculations, HELP!!!

Hi Andrew,
              First off, would you please insert the odd carriage 
return. Ireceived your message truncated to a single line of ??? 

> From:  Andrew Chin [SMTP:chinny-at-ozemail-dot-com.au]
> Sent:  Wednesday, April 15, 1998 2:22 PM
> To:  'Tesla List'
> Subject:  RE: Quarter Wave Calculations, HELP!!!

> I simply used a physics formula Frequency = Speed of light /
> Wavelength.  In the case of a quarter wavelength tesla coil, the
> wavelength in this case would be 4 times the length of wire used
> to wind

The length of wire won't correspond with the coil self-F like that 
i.e. a bare resonator will never resonate at a frequency such that 
the wire is 1/4 wavelength long in it. You can do it by adding the 
correct amount of Ctop but I haven't yet seen any good reason to do 
so (other than providing some top energy storage). If you don't 
believe me, measure all of your resonators without a topload. Just 
use Wheeler's L formula and Medhurst's C formula to predict your 
coil's frequency.