Tom,

I just modelled that coil in EZNEC and it was self-resonant at 7.5MHz
- very close to the Corum model prediction of 7.4137MHz.

Interesting that both EZNEC and the Corum are wrong and by the same
amount!

73,
Steve G3TXQ



On May 9, 10:06*pm, "Tom Donaly" wrote:

Did you make such a coil and measure its self-resonant frequency? The
reason I ask is that I put the dimensions of an old coil I had
(D=155mm,length=140mm,wire diameter=1.3mm,N=27 turns) into ON4AA's
calculator and got a self resonant number of 7.4137 Mhz. When I measured
it, though, it was 8.93 Mhz. Where did I go wrong? Maybe I entered the
numbers incorrectly.
73,
Tom Donaly, KA6RUH