Cecil Moore wrote:
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.

Please describe your test setup. Where was ground?

I'll tell you what, Cecil. If you'll test your coil, and
describe how you did it, I'll tell you what I did. Fair?
I know you're champing at the bit to claim my test setup was all
wrong and that I used standing wave current when I should have
been using traveling wave current, and all that, but you'll just
have to wait. I reported this in order to get you keyboard theorists
off your fundaments and start dealing with the real world. If you don't,
you'll forever be plagued by the nagging thought that I might be right.
Horrors!
73,
Tom Donaly, KA6RUH

(P.S. If you don't know how to test for a coil's self-resonant
frequency, you should go back to Texas A&M and ask for your money
back.)