I am wanting to build 1/2 wave end fed ground plane independent aerials for
2M and 70cms for use on
touring motorcycles for bike to bike comms.

At the moment we are using 5W hand helds with the helicals, but I was
wanting to experiment with half waves
better sited, to increase the max range possible between the bikes -
groundplanes are not practical. On 70cms
the aerials will be physically smaller but not sure how the range might be
affected / reduced

Has anyone suggestions on band to use and/or designs for suitable aerials,
or a link to a site with details ?

Thanks,

Nick