Re: New formula for secondary resonant frequency

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

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <paul-at-abelian.demon.co.uk>

John H. Couture wrote:

> The Ver 3.2 gives a much lower kHz (248.06) for this 1700 turn
> coil compared to the formula.

This might be expected if your program is using the Medhurst
capacitance. I would expect the prediction by Medhurst to error on
the low side by about 5 or 10% at this large h/d ratio. See the
comments in 

 http://www.abelian.demon.co.uk/tssp/misc.html

You can see that Medhurst is most in error at large h/d. The h/d of
10.11 of Marc's coil is a good test of any formula for this reason,
and Marc's careful measurements agree very well with precision
modeling at both the quarter and three-quarter wave resonances.

I'm afraid I don't have enough info on John's coil to be able to
do the calculations.

Regards,
--
Paul Nicholson,
Manchester, UK.
--