On Mar 23, 5:55*pm, Richard Fry wrote:
Also this link to a page from John Kraus' ANTENNAS FOR ALL
APPLICATIONS, 3rd Edition:http://i62.photobucket.com/albums/h8...y-woundVertica...

Kraus' short resonant normal-mode helical antenna uses close to 1/4WL
of conductor. We know that because of adjacent turn coupling, when a
conductor is coiled into a helical configuration, more conductor is
required to maintain a constant electrical length, e.g. 90 degrees in
this case. I suspect that Kraus' helical antenna example would be
resonant at about 1.8 times the design frequency rather than at the
design frequency. Please note the last line in the Kraus quote
regarding the advantage of a helix.

Since a helical monopole is 90 degrees long at the design frequency,
one wonders if half of the helix would be 45 degrees long at the
design frequency? And if the missing half of the antenna were replaced
by a whip to return to the original resonant frequency, why wouldn't
we have a base loaded antenna with the base loading coil occupying 45
degrees?
--
73, Cecil, w5dxp.com