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Re: Coil dimensions - oops!

Original poster: Ed Phillips <evp@xxxxxxxxxxx>

Original poster: Mddeming@xxxxxxx
In a message dated 5/28/06 12:33:55 P.M. Eastern Daylight Time, tesla@xxxxxxxxxx writes:
For a flat spiral primary,:

L=(rN)2 / (8r+11B)
 L is in microhenries
N is number of turns
r is AVERAGE radius of coil (inches) = r(inner) r(outer) / 2
B is width of coil (inches) = r(outer)-r(inner)

As many people probably noticed this should read:

r is AVERAGE radius of coil (inches) = [r(inner) + r(outer)] / 2

That's the hazard of writing emails after 3AM :^< zzzz

Matt D. "

Convenient and not too accurate a formula, but enough to size a primary big enough to allow tuning.