"Cecil Moore" wrote

Take your NEC helical model and adjust the frequency to
approximately double the resonant frequency and take a
look at the current distribution.

I have already done an illustration based on the currents in the NEC
comparison posted earlier, showing a helix and a linear monopole each about
6 degrees in aperture (link below).

This link shows that even though the length of wire used in the helix is
3.14 X the length used in the linear monopole, the current distribution
along their apertures essentially is the same, as will be the directivity
and radiation pattern of both versions.

This same equivalence would apply to the current distribution, directivity
and pattern of a linear, 1/4-WL monopole and a helically-wound monopole that
was 1/4-WL in aperture, but contained 1/2-WL of coiled wire.

http://i62.photobucket.com/albums/h8...le_Current.gif