"Cecil Moore" wrote
The standing-wave current envelope for the 180 degree long helical
is a sine wave with the current maximum point in the middle
of the helical.

That is true ONLY if the end-to-end length (height) of a normal-mode helical
monopole occupies about 180 degrees of a free-space wavelength.

If that helix occupies only about 90 degrees of a free-space wavelength,
then no matter how much linear wire length is contained in the coils of the
helix, that helical radiator will have the radiation resistance, pattern and
directivity characteristics of a 90-degree linear monopole of the same
end-to-end height.

The length of coiled wire in a helix of any physical length makes very
little difference in the current distribution along its aperture, its
directivity, or its radiation patterns.

Please forget about your previous posting. We are not talking about 6 deg.
electrically short helicals.

Rather than suggesting that my previous posting(s) on this subject should be
forgotten, perhaps they should be re-read -- especially the link to
http://i62.photobucket.com/albums/h8...le_Current.gif .