The multisection Franklin antenna for UHF has been widely published on
the web. The first design is by N9ZIA:

http://www.qsl.net/n9zia/wireless/col432/index.html

This antenna used ground plane radials for decoupling

A modification by N1HFX uses a sleeve and ferrite toroids for
decoupling:

www.rason.org/Projects/collant/collant.htm

There is also a design proposed by WA6SVT with a few variations in
which a tubular sleeve is used and the coax elements covered with
cupper tubes:

http://www.repeater-builder.com/ante...struction.html

I would like to build a pair of vertical multielement antennas for
mobile use (when standing still) use to be used in cdma450 cell fringe
zones. 7-9 dB gain should be enough to reach base stations of the
outskirts of cells.

I suppose that a combination of the principles outlined in the
articles by N1HFX and the ones cited around the WA6SVT design should
work. Any feedback would be appreciated.

Q: How come coils are not used to space half-wave elements from each
other? In several wifi designs, single loop coils are used. In some,
coils consist of several turns:

http://mobileaccess.de/wlan/download...0-all-inst.pdf

So, what size should a phasing coil be for 455 MHz?

Regards
Jonas/SM0WJY