K6MM on Helical Wound Vertical
Iβm interested in short vertical antennas, so I keep collecting links to interesting article. K6MM has a nice description of his work with a 25 foot tall HWV antenna for 160M, built from three segments of PVC pipe, a capacitance βtop hatβ and 8 ground radials.
Addendum: Another page describing a very compact HWV antenna for 20m.