Re: Primary calculations


I'm really surprised you find Wheeler's formula in error.  I have found it is 
quite accurate even when pushed to weird dimensions and aspects which you are not 
doing.  Are you sure you are using the radius of your coil and not the diameter 
in the formula:

   L(uH) = (r^2) * (N^2) / (9*r + 10*h)

   r = coil RADIUS in inches
   N = number of turns
   h = coil height in inches

If I'm being obvious and insulting, please ignore this message, but occasionally 
even the best of us misses something.


>Does anyone have a formula to calculate the inductance of a primary wound on
>a cylindrical form?  I am talking about 3/8" copper tubing wound on a 6.2"
>dia form with 3/8" spacing between turns.   Wheelers formula doesn't seem to
>Thanks,  Ed Sonderman