Dave wrote:

...
5/8 wavelength antennas do not require a ground plane, do they?

Yeah, in my experience, a vertical 5/8 will require the same as would be
necessary for a 1/4 vertical ... the 1/2 is nice in that advantage, only
requiring a minimal counterpoise.

A few I have seen articles and pictures from, swear the 5/8 beats out
the 1/2--I simply have not found that in actually comparisons. However,
in such situations, I suspect it may be something I am doing wrong, but
for the life of me, I can't find what it could be ... and, it SHOULD
produce a superior radiation pattern for my uses.

And, in a homebrew omni antenna for my 2.4Ghz router, I went 5/8,
mounted ~20ft. in the air, it works well.

Regards,
JS